CI
Professeur
Activité scientifique
Profil chercheur
Enseignant-chercheur à l’Université de Yaoundé I. Grade : Professeur.
Publications scientifiques
Marie T. Tandja, Cyprian Chunkang Mikwa, Serges A.M. Mejonang, Ledoux S. Pouamo, Tiberiu Roman, Mohammad Azam et 2 autre(s)
SSRN Electronic Journal
Aurélie M.K. Kuisseu, Bridget N. Ndosiri, Aminou Mohamadou, Ledoux S. Pouamo, Colince Nde, Frédéric Capet et 3 autre(s)
Open MIND
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Aurélie M.K. Kuisseu, Bridget N. Ndosiri, Aminou Mohamadou, Ledoux S. Pouamo, Colince Nde, Frédéric Capet et 3 autre(s)
Polyhedron
André G. Nguifo, Ledoux S. Pouamo, Serge Eteme Enama, Colince Nde, Martin Signé, James B. Orton et 3 autre(s)
SSRN Electronic Journal
André G. Nguifo, Ledoux S. Pouamo, Serge E. Eteme, Colince Nde, Martin Signé, James B. Orton et 3 autre(s)
Journal of Molecular Structure
Serges A.M. Mejonang, Bridget N. Ndosiri, Ledoux S. Pouamo, Idelle N. Kamga, Colince Nde, Mohammad Azam et 1 autre(s)
Journal of Molecular Structure
Serges A.M. Mejonang, Bridget N. Ndosiri, Ledoux S. Pouamo, Idelle N. Kamga, Colince Nde, Boniface P. T. Fokwa et 1 autre(s)
SSRN Electronic Journal
Colince Nde, Adam Bouraima, Bridget N. Ndosiri, Idelle N. Kamga, Ledoux S. Pouamo, Frédéric Capet et 2 autre(s)
Polyhedron
An oxalato-bridged heterometallic heptanuclear [K 5 I Fe 2 III ] hybrid salt, (CH 6 N 3 )[K 5 (H 2 O) 4 Fe 2 (C 2 O 4 ) 6 ] ( 1 ) (CH 6 N 3 + = guanidinium cation) has been synthesized and characterized by elemental and thermal analyses, IR spectroscopy, single-crystal X-ray diffraction, EPR and SQUID magnetometry. The asymmetric unit in 1 is composed of a dimetallic heptanuclear [K 5 (H 2 O) 4 Fe 2 (C 2 O 4 ) 6 ] − anionic complex and a guanidinium CH 6 N 3 + cation insuring the charge compensation. Each Fe 3+ center in the anionic complex is six-coordinate in a distorted octahedron defined by three chelating oxalato(2-) ligands. In contrast, the coordination numbers for K + centers range from 7 to 9. The structural feature of focal interest in 1 is formation of an extended anionic network encapsulating guanidinium cations. This structure can be considered a sheet-MOF, where metal ions and oxalates (linkers) form infinite 2D units. The 3-D supramolecular architecture is stabilized by O H∙∙∙O and N H∙∙∙O hydrogen bonds linking polymeric oxalato-bridged anionic assemblies and organic cations. The thermal studies confirmed the anhydrous character of salt 1 and showed a three-step decomposition to yield a mixture of Fe 2 O 3 and K 2 O as final residue. EPR spectrum of 1 is in accordance with the oxidation state + 3 of the iron center in an octahedral environment. Temperature-dependence susceptibility measurements investigated in the temperature range 2–300 K revealed weak antiferromagnetic coupling at low temperatures in salt 1 . The distributions of different types of intermolecular interactions in the crystal structure were quantified by Hirshfeld surface analysis and their associated fingerprint plots.
Colince Nde, Augustin N. Nana, Idelle N. Kamga, Mohammad Azam, Frédéric Capet, Michel Foulon et 1 autre(s)
Journal of Molecular Structure
Ledoux S. Pouamo, Carole F.N. Nguemdzi, Mohammad Azam, Diana Luong, Kate A. Gibson, Wangxiang Li et 3 autre(s)
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Tanyi Rogers Fomuta, Golngar Djimassingar, Jean Ngouné, Nana Odette Ngnabeuye, Jean Jacques Anguilé, Justin Nenwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Coustel M. N. Choubeu, Bridget N. Ndosiri, Hervé Vezin, Claire Minaud, James B. Orton, Simon J. Coles et 1 autre(s)
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Clémence Eboga Tanke, Bridget N. Ndosiri, Yves A. Mbiangué, Gouet Bebga, Justin Nenwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Coustel M. N. Choubeu, Bridget N. Ndosiri, Hervé Vezin, Claire Minaud, James B. Orton, Simon J. Coles et 1 autre(s)
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Cyrielle L. F. Dazem, Francoise M. Amombo Noa, Justin Nenwa, Lars Öhrström
CrystEngComm
Network topology analysis is applied to a large number of mineral and synthetic oxalates, and is shown to be a superior method in describing and communicating the structure of these materials, including the first natural MOF weddellite.
Cyrielle L. F. Dazem, Bridget N. Ndosiri, Emmanuel N. Nfor, Roberto Köferstein, Pritam Shankhari, Boniface P. T. Fokwa et 1 autre(s)
Journal of Molecular Structure
Carole F.N. Nguemdzi, Frédéric Capet, Jean Ngouné, Gouet Bebga, Michel Foulon, Justin Nenwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Carole F.N. Nguemdzi, Frédéric Capet, Jean Ngouné, Gouet Bebga, Michel Foulon, Justin Nenwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Clémence T. Eboga, Gouet Bebga, Yves A. Mbiangué, Emmanuel N. Nfor, Patrick L. Djonwouo, Michel M. Bélombé et 1 autre(s)
Open Journal of Inorganic Chemistry
Reaction of Ba0.50[Ag2Cr(C2O4)3]·5H2O with Ag2SO4 in an aqueous solution of sulfuric acid (pH ≈ 3) yielded the silver(I)/chromium(III) oxalate salt H0.50[Ag2.50Cr(C2O4)3]·5H2O (1). Compound 1 can be best described as an anionic silver-deficient oxalatochromate(III) complex [Ag2.50Cr(C2O4)3]0.5- with nanochannels containing hydrogen-bonded water molecules and protons. Thermal analyses show significant weight losses corresponding to the elimination of water molecules of crystallization followed by the decomposition of the network.
Tanyi Rogers Fomuta, Jean Ngouné, Golngar Djimassingar, Tayo Alain Djampouo, Junior Ma Ntep Tobie Matemb, Jean Jacques Anguilé et 1 autre(s)
Open Journal of Inorganic Chemistry
The new salt bis(4,5-dihydro-1H-benzo[g]indazole)silver(I) hexafluorophosphate, [Ag(N2H10C11)2]PF6, has been synthesized in methanol at ambient temperature and characterized by elemental and thermal analyses, FTIR and 1HNMR spectroscopies, Rietveld refinement from powder diffraction data and DFT studies. The salt crystallizes in the triclinic space group P-1 with the parameters: a = 7.776 Å, b = 8.676 Å, c = 9.226 Å, α = 69.27° β = 89.86°, γ = 74.50°, V = 558.02 Å3, Z = 1. In the structure, the silver center is coordinated to two nitrogen atoms from two 4,5-dihydro-1H-benzo[g]indazole ligands, forming a centrosymmetric complex cation, [Ag(N2H10C11)2]+, with a linear coordination geometry around the silver center. The hexafluorophosphate ion, , acts as counter anion. The crystal packing is governed by N-H···F and C-H···F hydrogen bonds that interconnect the ionic constituents and Ag···F and Ag···π interactions help for the stabilization of the packing. The optimized structure was obtained at B3LYP/LanL2DZ level in the gas phase. The stability and reactivity of the structure were studied using respectively HOMO-LUMO gap and electronic global quantities (ionization potential (I) and electron affinity (A)) as descriptors.
Justin Nenwa, Issoufou Kaboré, Yves A. Mbiangué, Patrick L. Djonwouo, Peter T. Ndifon
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Djuikom Sado Yanick Gaëlle, Moise Ondoh Agwara, Divine Mbom Yufanyi, Justin Nenwa, R. Jagan
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Edith D. Djomo, F. Capet, Justin Nenwa, Michel M. Bélombé, Michel Foulon
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Noé Makon Ma Houga, F. Capet, Justin Nenwa, Gouet Bebga, Michel Foulon
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Justin Nenwa, Issoufou Kaboré, Yves A. Mbiangué, Patrick L. Djonwouo, Peter T. Ndifon
Crystal Structure Theory and Applications
A new compound of general formula {[(H2O)2K(μ-H2O)Sr]@[Cr(C2O4)3]}n (1) has been synthesized in water and characterized by elemental and thermal analyses, EDX, IR and UV-Vis spectroscopies and by single crystal X-ray structure determination. Compound 1 crystallizes in the chiral space group Fdd2 of orthorhombic system with a = 14.110 (4) ?, b = 36.074 (11)?, c =11.034 (3)? and Z = 16. Compound 1 is a coordination polymer in which the three-dimensional lattice framework is realized by the interconnectivity between K+ cations, Sr2+ cations, aqua ligands and [Cr(C2O4)3]3– complex anions. The asymmetric unit of 1 consists of one cationic motif formally written [(H2O)2K(μ-H2O)Sr]3+ and one anionic entity, [Cr(C2O4)3]3–. The K+ and Sr2+ ions in the cationic motif are both eight-coordinate while the Cr3+ ions in the anionic complex are six-coordinate in a distorted octahedral geometry. Coulombic interactions between the ionic motifs and the three-dimensional H-bonding involving aqua ligands help to consolidate the bulk structure. Thermogra-vimetric analysis (TGA) shows that compound 1 is stable to heat up to ca. 80℃.
Justin Nenwa, Patrick L. Djonwouo, Emmanuel N. Nfor, Michel M. Bélombé, Erwann Jeanneau, Mohamed Mbarki et 1 autre(s)
Zeitschrift für Naturforschung B
The dimeric copper(II) complex [Cu(C 2 O 4 )(H 2 oxado)(H 2 O)]2 (1), where H 2 oxado=oxamide dioxime, has been synthesized in water and characterized by elemental and thermal analyses, IR spectroscopy, and single-crystal X-ray diffraction. Complex 1 is composed of two neutral [Cu(C 2 O 4 )(H 2 oxado)(H 2 O)] entities connected by Cu-O bonds between oxalate oxygen atoms and copper(II) ions, thereby producing a centrosymmetric dimer, with the Cu(II) centers exhibiting a strongly distorted octahedral coordination. Neighboring dimers are hydrogen-bonded through O- H···O interactions leading overall to a layer structure. Thermal analyses of complex 1 showed two significant weight losses corresponding to the coordinated water molecules, followed by the decomposition of the network. Variable-temperature (10 - 300 K) magnetic susceptibility measurements revealed very weak antiferromagnetic interactions (θ = 0:86 K from Curie-Weiss law behavior) within the dinuclear unit
Michel M. Bélombé, Justin Nenwa, N.A.S.N. Tchuisse, Franziska Emmerling, S. Obbade, A. Semmoud et 1 autre(s)
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Jean Ngouné, Corrado Di Nicola, Justin Nenwa, Claudio Pettinari, Eleuterio Álvarez, Siméon Ponou
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Justin Nenwa, Gouet Bebga, Martin Signé, Michel M. Bélombé, Mohamed Mbarki, Boniface P. T. Fokwa
Acta Crystallographica Section E Structure Reports Online
In the title hybrid salt, (C(5)H(7)N(2))[Cr(H(2)O)(2)(C(2)O(4))(2)], the Cr(III) ion is coordinated in a slightly distorted octa-hedral environment by four O atoms from two oxalate ligands in the equatorial plane and by two water O atoms in the axial sites. The 2-amino-pyridinium cation is disordered over two sets of sites in a 0.800 (7):0.200 (7) ratio. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds connect the components into a three-dimensional network. The crystal studied was an inversion twin with components in a ratio 0.75 (2):0.25 (2).
Jean Ngouné, Corrado Di Nicola, Justin Nenwa, Claudio Pettinari, Eleuterio Álvarez, Siméon Ponou
Transition Metal Chemistry
Michel M. Bélombé, Justin Nenwa, Jean Ngouné, Eleuterio Álvarez, Agustı́n Galindo
Acta Crystallographica Section E Structure Reports Online
The unit cell of the title compound, poly[[μ-aqua-μ-hydroxido-di-μ-oxalato-chromium(III)disodium] monohydrate], {[CrNa(2)(C(2)O(4))(2)(OH)(H(2)O)]·H(2)O}(n), contains four [Na1(μ-H(2)O)Na2][(C(2)O(4))(2)Cr(μ-OH)·H(2)O] formula units, each of which consists of two crystallographically independent Na(+) sites (bridged by one aqua ligand), one half of a centrosymmetric di-μ-hydroxido-bis-[cis-bis-(oxalato)chromate(III)] dimer, [(C(2)O(4))(2)Cr(μ-OH)(2)Cr(C(2)O(4))(2)](4-), and one uncoordin-ated water mol-ecule. The structure is best described as a coordination polymer in which the three-dimensional lattice framework is realized by the inter-connection of the metallic atoms via the O atoms of the aqua, hydroxide and oxalate ligands. One Na atom is hepta-coordinated by one water, one hydroxide and five oxalate O atoms, whilst the other is penta-coordinated by one water and four oxalate O atoms. The coordination around the Cr(3+) sites is pseudo-octa-hedral, involving four aqua and two hydroxide O atoms. Adjacent Na atoms are separated by 3.593 (2) Å, whereas the intra-dimer Cr⋯Cr spacing is 2.978 (1) Å. The crystal structure is consolidated by extended relatively weak O-H⋯O hydrogen bonding with O⋯O distances ranging from 2.808 (4) to 3.276 (5) Å.
Justin Nenwa, Michel M. Bélombé, Jean Ngouné, Boniface P. T. Fokwa
Acta Crystallographica Section E Structure Reports Online
In the title salt, (C(7)H(11)N(2))[Cr(C(2)O(4))(2)(H(2)O)(2)], the asymmetric unit contains one half-cation and one half-anion. The Cr atom, the C and N atoms involved in C- N(exocyclic) bonding and the N and H atoms of N-H groups lie on twofold rotation axis. The Cr(III) atom of the complex anion is six-coordinated in a distorted (4 + 2) octa-hedral geometry with four equatorial O atoms of two nearly coplanar oxalate and two quasi-axial aqua O atoms. In the crystal, the protonated N atoms of the pyridine rings are hydrogen bonded to the carbonyl O atoms of the anions, forming chains along [010]. These chains are connected by lateral O-H⋯O hydrogen bonds, stabilizing the structure.
Michel M. Bélombé, Justin Nenwa, Yves-A. Mbiangué, Gouet Bebga, Felicite Majoumo‐Mbe, Evamarie Hey‐Hawkins et 1 autre(s)
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Michel M. Bélombé, Justin Nenwa, Evamarie Hey‐Hawkins, Peter Lönnecke, Peter Strauch, Klaus R. Koch
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Justin Nenwa, Michel M. Bélombé, Boniface P. T. Fokwa, R. Dronskowski
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Michel M. Bélombé, Justin Nenwa, Yves A. Mbiangué, Boniface P. T. Fokwa, R. Dronskowski
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Michel M. Bélombé, Justin Nenwa, Gouet Bebga, Boniface P. T. Fokwa, Richard Dronskowski
Acta Crystallographica Section E Structure Reports Online
In the title compound, [Co(C2H6N4O2)3]2(C2O4)(SO4)212H2O, the Co3+ ion adopts a distorted octahedral coordination involving six imino N atoms of three bidentate oxamide dioxime ligands. The oxalate ion is centrosymmetric. The bulk structure is consolidated by a network of O—H⋯O and N—H⋯O hydrogen bonds, interconnecting the building blocks in such a manner that the framework delineates infinite channels parallel to [100]. The 12 water molecules are lodged inside the channels, six of them being O—H⋯O and N—H⋯O bonded to the ionic species, whilst the other six, located along the central axis of the channel, form infinite cyclohexameric water tapes. Two of the water molecules are disordered over two sites, in 0.786 (7):0.214 (7) and 0.637 (8):0.363 (8) ratios.
Michel M. Bélombé, Justin Nenwa, Gouet Bebga, Boniface P. T. Fokwa, R. Dronskowski
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Michel M. Bélombé, Justin Nenwa, Boniface P. T. Fokwa, R. Dronskowski
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Michel M. Bélombé, Justin Nenwa, Astride L. Kammoe, Pierre F. P. Poudeu
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Michel M. Bélombé, Justin Nenwa, Yves-A. Mbiangué, Germain Evina Nnanga, Israël M. Mbomekallé, Evamarie Hey‐Hawkins et 2 autre(s)
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Michel M. Bélombé, Justin Nenwa, Yves-A. Mbiangué, Germain Evina Nnanga, Israël M. Mbomekallé, Evamarie Hey‐Hawkins et 2 autre(s)
Dalton Transactions
Reaction of BaII and CrIII,VI compounds with oxalates in water affords a salt of empirical formula {Ba6(H2O)17[Cr(ox)3]4}·7H2O (1), consistent with the expected 3BaII/2CrIII ratio; the triclinic structure is held together by unusual water and oxalate bridges, and compound 1 proved to be suitable for the synthesis of new salts with chiral cations and anions.
Aurélie M.K. Kuisseu, Bridget N. Ndosiri, Aminou Mohamadou, Ledoux S. Pouamo, Colince Nde, Frédéric Capet et 3 autre(s)
SSRN Electronic Journal
Anselme E. K. Diffo, Bridget N. Ndosiri, Ledoux S. Pouamo, Colince Nde, Martin Signé, Tiberiu Roman et 2 autre(s)
Polyhedron
Anselme E. K. Diffo, Bridget N. Ndosiri, Ledoux S. Pouamo, Colince Nde, Martin Signé, Tiberiu Roman et 2 autre(s)
SSRN Electronic Journal
Ornela B.T. Tchougong, Carole F.N. Nguemdzi, Bridget N. Ndosiri, Ledoux S. Pouamo, Idelle N. Kamga, Mohammad Azam et 3 autre(s)
SSRN Electronic Journal
Ornela B.T. Tchougong, Carole F.N. Nguemdzi, Bridget N. Ndosiri, Ledoux S. Pouamo, Colince Nde, Mohammad Azam et 3 autre(s)
Polyhedron
Ornela B.T. Tchougong, Carole F.N. Nguemdzi, Bridget N. Ndosiri, Ledoux S. Pouamo, Colince Nde, Mohammad Azam et 3 autre(s)
SSRN Electronic Journal
Cyrielle L. F. Dazem, A. Ken Inge, Dominique Luneau, Lars Öhrström, Justin Nenwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Cyrielle L. F. Dazem, A. Ken Inge, Dominique Luneau, Lars Öhrström, Justin Nenwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Line Njiki, Bridget N. Ndosiri, Augustin N. Nana, Adam Bouraima, Ledoux S. Pouamo, Frédéric Capet et 2 autre(s)
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Line Njiki, Bridget N. Ndosiri, Augustin N. Nana, Adam Bouraima, Ledoux S. Pouamo, Frédéric Capet et 2 autre(s)
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Cyrielle L. F. Dazem, A. Ken Inge, Dominique Luneau, Lars Öhrström, Justin Nenwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Cyrielle L. F. Dazem, A. Ken Inge, Dominique Luneau, Lars Öhrström, Justin Nenwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Colince Nde, Adam Bouraima, Bridget N. Ndosiri, Idelle N. Kamga, Ledoux S. Pouamo, Frédéric Capet et 2 autre(s)
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Line Njiki, Bridget N. Ndosiri, Augustin N. Nana, Adam Bouraima, Ledoux S. Pouamo, Frédéric Capet et 2 autre(s)
Polyhedron
Ledoux S. Pouamo, Carole F.N. Nguemdzi, Mohammad Azam, Diana Luong, Kate A. Gibson, Wangxiang Li et 3 autre(s)
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Colince Nde, Augustin N. Nana, Idelle N. Kamga, Mohammad Azam, Frédéric Capet, Michel Foulon et 1 autre(s)
The Cambridge Structural Database
Cyrielle L. F. Dazem, A. Ken Inge, Dominique Luneau, Lars Öhrström, Justin Nenwa
CrystEngComm
In the Cu( ii ) oxalate salts of (C 5 H 7 N 2 O) 2 [Cu(C 2 O 4 ) 2 ] 1 and C 13 H 16 N 2 [Cu(C 2 O 4 ) 2 ] 2, the oxalate adopts different coordination modes: the common bidentate chelating oxalate in 1 and the relatively scarce μ-oxalato-κ 3 O 1 ,O 2 :O 1 ′ in 2.
Ledoux S. Pouamo, Carole F.N. Nguemdzi, Mohammad Azam, Diana Luong, Kate A. Gibson, Wangxiang Li et 3 autre(s)
Journal of Molecular Structure
Coustel M. N. Choubeu, Bridget N. Ndosiri, Hervé Vezin, Claire Minaud, James B. Orton, Simon J. Coles et 1 autre(s)
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Idelle N. Kamga, Augustin N. Nana, Bridget N. Ndosiri, Frédéric Capet, Michel Foulon, Justin Nenwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Idelle N. Kamga, Bridget N. Ndosiri, Augustin N. Nana, Tiberiu Roman, Ledoux S. Pouamo, Justin Nenwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Idelle N. Kamga, Bridget N. Ndosiri, Augustin N. Nana, Tiberiu Roman, Ledoux S. Pouamo, Justin Nenwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Djogang Lucie Karelle, Forlemu Neville, Alphonse Emadak, Njabon Njankwa Eric, Issofa Patouossa, Justin Nenwa
Computational Chemistry
Malaria is a life-threatening disease responsible for half a million death annually, and with nearly half of the world’s population at risk. The rapid drop in observed cases of malaria in the last two decades has been due to a combination of preventive and therapeutic remedies. However, the absence of a vaccine, new antimalarial chemotherapies and increased parasitic resistance have led to a plateau of infections and renewed research interest in target human and Plasmodium (the malaria parasite) receptors and new drugs. In this study, the impact of mutation on the affinity on antimalarial drugs with the bifunctional enzyme complex, dihydrofolate reductase (DHFR) is explored. In addition, homology modeling is used to build the three-dimensional models of the enzymes Plasmodium telomerase reverse-transcriptase (pf-TERT) and Plasmodium dihydropteroate synthetase (pf-DHPS) to determine their affinity with antimalarial drugs. The interaction energies and stable complexes formed between these enzymes and antimalarial drugs (chloroquine, artemisinin, primaquine, pyrimethamine, sulfadoxine and pentamidine) were modelled using AutoDock vina. Our data indicate that pf-TERT and pf-DHPS form stable complexes with the antimalarial ligands with affinity ranging from ?4.0 to ?6.9 kcal/mol. The affinity with crystal structures of DHFR receptors was higher ranging from ?6.0 to ?10.0 kcal/mol. The affinity to DHFR also decreases with the mutation a confirmation of the source of resistance. The highest affinity interaction for all the receptors modeled is observed with Artemisinin a benchmark antimalarial drug. This can be attributed to the size, shape and dipolar surface of the ligand. The observed complexes are stabilized by strategic active site polar and non-polar contacts.
Idelle N. Kamga, Bridget N. Ndosiri, Augustin N. Nana, Tiberiu Roman, Ledoux S. Pouamo, Justin Nenwa
Polyhedron
Idelle N. Kamga, Augustin N. Nana, Bridget N. Ndosiri, Frédéric Capet, Michel Foulon, Justin Nenwa
Zeitschrift für Naturforschung B
Abstract A new salt (CH 6 N 3 )[ t -Cr(C 2 O 4 ) 2 (H 2 O) 2 ]·2H 2 O ( 1 ) (CH 6 N 3 + = guanidinium cation) has been synthesized and characterized by single-crystal X-ray diffraction, FT-IR and UV–Vis spectroscopies, elemental and thermogravimetric analyses. In the crystal structure of 1 , the chromate(III) ion lies on an inversion center in the form of an elongated octahedron. The coordination sphere consists of four oxygen atoms of two chelating oxalato ligands in the equatorial plane and two axial oxygen atoms of water ligands. The structural feature of focal interest in the structure of 1 is the formation of pillars of [Cr(C 2 O 4 ) 2 (H 2 O) 2 ] − complex anions and CH 6 N 3 + guanidinium cations, with the next-neighbor cations rotated by an angle of 60° relative to each other. O–H···O and N–H···O hydrogen bonds play an important role in the construction of the three-dimensional network. The electron paramagnetic resonance (EPR) and magnetic properties of 1 have also been investigated.
Coustel M. N. Choubeu, Bridget N. Ndosiri, Hervé Vezin, Claire Minaud, James B. Orton, Simon J. Coles et 1 autre(s)
Journal of Coordination Chemistry
By modifying the stoichiometric ratio of starting materials, two tris(oxalato)chromate(III) salts, (C7H11N2)3[Cr(C2O4)3] (1) and (C5H8N3)2(NH4)[Cr(C2O4)3]·2H2O (2) {(C7H11N2)+ = 2-amino-4,6-dimethylpyridinium, (C5H8N3)+ = 2,6-diaminopyridinium}, were synthesized and characterized by elemental and thermal analyses, single-crystal X-ray diffraction, IR and UV − Vis spectroscopies, EPR and SQUID measurements. Salt 1 exhibits a 3-D supramolecular framework based on [Cr(C2O4)3]3- and 2-amino-4,6-dimethylpyridinim cations, (C7H11N2)+, via N–H···O hydrogen bonds. Interestingly, π–π stacking interactions between pyridine rings contribute to the stabilization of the crystal packing. In contrast to salt 1, no π–π stacking interactions are observed in the mixed-cation salt 2 and its crystal packing is consolidated by N–H···O and O − H···O hydrogen bonds. EPR spectra of 1 and 2 are consistent with the oxidation state +3 of the chromium center in an octahedral environment. Temperature-dependence of the magnetic susceptibility data investigated from 2 to 300 K revealed the existence of zero-field splitting effects (ZFS) for Cr(III) ions in both compounds.
Coustel M. N. Choubeu, Bridget N. Ndosiri, Hervé Vezin, Claire Minaud, James B. Orton, Simon J. Coles et 1 autre(s)
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Gouet Bebga, Emmanuel N. Nfor, Yves A. Mbiangué, Patrick L. Djonwouo, Justin Nenwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Augustin N. Nana, Delia A. Haynes, Hervé Vezin, Claire Minaud, Pritam Shankhari, Boniface P. T. Fokwa et 1 autre(s)
Journal of Molecular Structure
Bridget N. Ndosiri, Emmanuel N. Nfor, Jérôme Marrot, Aminou Mohamadou, Justin Nenwa
Crystal Structure Theory and Applications
A novel chiral Nickel (II) complex of N-(2-pyridylmethyl)-L-alanine (Hpyala) 1 has been prepared and structurally characterized by elemental analysis, FT-IR, UV-visible, TGA and single crystal X-ray diffraction techniques. Complex 1 crystallizes in an orthorhombic P212121 space group. The nickel (II) centre in the complex adopts a distorted octahedral geometry. This compound has been seen to exhibit structural diversity resulting from the number of lattice water molecules. The photoluminescent properties of this compound which have also been investigated, indicates the potential application in luminescence.
Coustel M. N. Choubeu, Bridget N. Ndosiri, Hervé Vezin, Claire Minaud, James B. Orton, Simon J. Coles et 1 autre(s)
Polyhedron
Carole F.N. Nguemdzi, Frédéric Capet, Jean Ngouné, Gouet Bebga, Michel Foulon, Justin Nenwa
Journal of Coordination Chemistry
Two organic–inorganic hybrid salts, tris(2-amino-4,6-dimethylpyridinium) tris(oxalato)ferrate(III), (C7H11N2)3[Fe(C2O4)3] (1), and tris(4-dimethylaminopyridinium) tris(oxalato)ferrate(III) tetrahydrate, (C7H11N2)3[Fe(C2O4)3]·4H2O (2), have been synthesized and characterized by elemental and thermal analyses, IR spectroscopy, single-crystal X-ray diffraction, and SQUID magnetometry. Compounds 1 and 2 crystallize in triclinic P-1 and monoclinic C2/c space groups, respectively. Each compound contains the anionic complex [Fe(C2O4)3]3- in which the central metal is six-coordinate in a slightly distorted octahedron defined by three chelating oxalate(2-) ligands. The two substituted pyridinium cations are isomers. However, due to the great steric hindrance provided by the bulky cation, 2-amino-4,6-dimethylpyridinium, only the 4-dimethylaminopyridinium cation, the smallest of this series, led to formation of 2 with enough vacant spaces to be occupied by four solvent water molecules. In the crystals, cations and anions are connected via hydrogen-bonds of the types N–H⋯O in 1 and N–H⋯O and O–H⋯O in 2, with π–π stacking interactions between the pyridine rings stabilizing the 3-D framework. The thermal studies confirmed the anhydrous character of salt 1 and the presence of water molecules in salt 2. The magnetic susceptibility measurements in the 2–300 K temperature range revealed weak antiferromagnetic coupling in the two salts.
Tanyi Rogers Fomuta, Golngar Djimassingar, Jean Ngouné, Nana Odette Ngnabeuye, Jean Jacques Anguilé, Justin Nenwa
Crystal Structure Theory and Applications
A new silver complex salt [Ag(N2C11H10)2]NO3 (where N2C11H10 = 4,5-dihydro-1H-benzo[g]indazole), has been synthesized and characterized by elemental and thermal analyses, IR and 1HNMR spectroscopies, single crystal X-ray structure determination and DFT studies. Its molecular structure comprises of a silver center coordinated to two nitrogen atoms from two 4,5-dihydro-1H-benzo[g]indazole molecule giving rise to a cationic complex entity, [Ag(N2C11H10)2]+ with as counter ion. The bulk structure is consolidated by N–H…O, C–H…π, Ag…π and Ag…O intermolecular interactions, thus generating a pseudo-helical network. The optimized structure, frontier molecular orbitals (HOMO and LUMO) and global reactivity descriptors were investigated by performing DFT calculations.
Jean Ngouné, Jean Jacques Anguilé, Justin Nenwa, Golngar Djimassinga, Claudio Pettinari, Eleuterio Álvarez et 1 autre(s)
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Djuikom Sado Yanick Gaëlle, Moise Ondoh Agwara, Divine Mbom Yufanyi, Justin Nenwa, R. Jagan
Inorganic and Nano-Metal Chemistry
A novel Cu(II) complex with mixed ligands, [azido-bis(1,10-phenanthroline-κ2N,N′)copper(II)]nitrate hydrate has been synthesized and was characterized by physicochemical and spectroscopic methods. The central Cu(II) atom is five coordinate with four N atoms of two 1,10-phenanthroline molecules and one terminal N atom from an azide anion, giving a distorted trigonal bipyramidal geometry with a CuN5 chromophore. The molecular structure of the compound is consolidated by H-bonding and face-to face π-π stacking between the aromatic rings of 1,10-phenanthroline ligand. The ligands, metal salt, and the complex were also evaluated for their antimicrobial activities in vitro.
Jean Ngouné, Jean Jacques Anguilé, Justin Nenwa, Golngar Djimassinga, Claudio Pettinari, Eleuterio Álvarez et 1 autre(s)
Inorganica Chimica Acta
Clémence Eboga Tanke, Bridget N. Ndosiri, Yves A. Mbiangué, Gouet Bebga, Justin Nenwa
American Journal of Analytical Chemistry
A novel mixed barium(II)/silver(I)/chromium(III) oxalate salt, Ba0.5Ag2[Cr(C2O4)3]·5H2O (1), with open architecture has been synthesized in water and characterized by elemental analysis, vibrational and electronic spectra, and single crystal X-ray structure determination. Compound 1 crystallizes in a monoclinic space group C2/c, with unit cell parameters a = 18.179(3), b = 14.743(2), c = 12.278(2)Å, β = 113.821(3), V = 3010.34(90) Å3, Z = 8. The structure is characterized by a network of anionic [Cr(C2O4)3]3- units connected through the O atoms of the oxalates to Ba2+ and Ag+ sites, forming a three-dimensional coordination polymer with one-dimensional isolated nanochannels parallel to the c axis, and encapsulating hydrogen-bonded guest water molecules. The bulk structure is consolidated by O–H···O bridgings within the nanochannels and by coulombic interactions.
Jean Ngouné, Anguile Jean Jacques, Justin Nenwa, Djimassinga Golngar, Pettinari Claudio, Alvarez Eleuterio et 1 autre(s)
Inorganica Chimica Acta
Noé Makon Ma Houga, Brian S. Dolinar, Justin Nenwa, Gouet Bebga
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Justin Nenwa, Edith D. Djomo, Emmanuel N. Nfor, Patrick L. Djonwouo, Mohamed Mbarki, Boniface P. T. Fokwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Justin Nenwa, Edith D. Djomo, Emmanuel N. Nfor, Patrick L. Djonwouo, Mohamed Mbarki, Boniface P. T. Fokwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Edith D. Djomo, Frédéric Capet, Justin Nenwa, Michel M. Bélombé, Michel Foulon
Acta Crystallographica Section E Crystallographic Communications
The Fe(III) ions in the hybrid title salt, (C7H11N2)[Fe(C2O4)2(H2O)2]·0.5H2O, show a distorted octa-hedral coordination environment, with four O atoms from two chelating oxalate dianions and two O atoms from two cis aqua ligands. The average Fe-O(oxalate) bond length [2.00 (2) Å] is shorter than the average Fe-O(water) bond length [2.027 (19) Å]. The ionic components are connected via inter-molecular N-H⋯O and O-H⋯O hydrogen bonds into a three-dimensional network.
Noé Makon Ma Houga, Frédéric Capet, Justin Nenwa, Gouet Bebga, Michel Foulon
Acta Crystallographica Section E Crystallographic Communications
In the title hybrid salt, (C7H11N2)3[Cr(C2O4)3]·4H2O, the central Cr(III) ion of the complex anion (point group symmetry 2) is coordinated by six O atoms from three chelating oxalate(2-) ligands in a slightly distorted octa-hedral coordination sphere. The Cr-O bond lengths vary from 1.9577 (11) to 1.9804 (11) Å, while the chelate O-Cr-O angles range from 82.11 (6) to 93.41 (5)°. The 4-(di-methyl-amino)-pyridinium cations (one situated in a general position and one on a twofold rotation axis) are protonated at the pyridine N atoms. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds link the cations and anions into a three-dimensional network. π-π inter-actions between the pyridine rings of adjacent cations provide additional stabilization of the crystal packing, with the closest centroid-to-centroid distances being 3.541 (1) and 3.575 (1) Å.
Gouet Bebga, Emmanuel N. Nfor, Yves A. Mbiangué, Patrick L. Djonwouo, Justin Nenwa
Crystal Structure Theory and Applications
A new cobalt(II) complex, [Co(H2 oxado)3 ]C2 O4 H2 oxado·2H2 O (H2 oxado = oxamide dioxime), has been synthesized in aqueous solution and characterized by elemental analysis and single crystal X-ray structure determination. The complex crystallizes in the triclinic space group P-1, with the parameters a = 9.46(4), b = 11.84(5), c = 12. 81(5) Å, α = 104.94(6), β = 99.29(5), γ = 106.73(5), V = 1284(9) Å3, Z = 2. The central cobalt(II) cation is pseudo-octahedrally coordinated by six imino N atoms of the neutral oxamide dioxime ligand. In the solid state, each of the following bricks, namely the cationic complexes, the oxalate dianions as well as the oxamide dioxime crystallization molecules, pile up parallel to the a axis. The bulk structure is consolidated by an extended three-dimensional network of hydrogen bridgings—that link the ionic partners, oxamide dioxime and water molecules to one another—and by coulombic interactions.
Justin Nenwa, Edith D. Djomo, Emmanuel N. Nfor, Patrick L. Djonwouo, Mohamed Mbarki, Boniface P. T. Fokwa
Polyhedron
Emmanuel N. Nfor, Luke L. Keenan, Justin Nenwa, Peter T. Ndifon, Romanus N. Njong, Christelle N. T. Dzesse et 1 autre(s)
Crystal Structure Theory and Applications
A novel dinuclear complex [Co2(atr)3(mal)2(H2O)2]·4H2O(1) (atr = 4-amino-1,2,4-triazole and mal = malonic acid) containing mixed N and O-donor atoms has been prepared and structurally characterized. The structure is made up of the symmetrically 1, 2, 4-triazole bridged [Co2(atr)3(mal)2(H2O)2] moiety and four lattice water molecules. The single crystal X-ray analysis reveals that the complex has a distorted octahedral structure. Magnetic susceptibility measurements reveals that antiferromagnetic interactions exists between the high spin Co(II) ions within the dinuclear unit.
Justin Nenwa, Patrick L. Djonwouo, Emmanuel N. Nfor, Michel M. Bélombé, Erwann Jeanneau, Mohamed Mbarki et 1 autre(s)
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Noé Makon Ma Houga, Brian S. Dolinar, Justin Nenwa, Gouet Bebga
Open Journal of Inorganic Chemistry
Reaction of Ba(NO3)2 with Fe(NO3)3·9H2O and H2C2O4·2H2O in aqueous medium readily affords, in high yield, the bimetallic complex polymer of chemical composition {Ba6(H2O)17[Fe(C2O4)3]4}·7H2O (1), consistent with the expected ratio of 3BaII vs. 2FeIII. Compound 1 was fully characterized by elemental and thermal analyses, vibrational FTIR spectroscopy, and by single crystal X-ray structure determination. The bulk structure of 1 is a 3-D metal-organic framework held together by intermetallic linkages across oxalate and aqua oxygen bridgings. Thermal analyses of 1 show significant weight losses corresponding to water molecules (lattice and coordinated), followed by the decomposition of the network.
Jean Ngouné, Corrado Di Nicola, Justin Nenwa, Claudio Pettinari, Eleuterio Álvarez, Siméon Ponou
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Emmanuel N. Nfor, Peter F. Asobo, Justin Nenwa, Oswald Ndi Nfor, Julius N. Njapba, Romanus N. Njong et 1 autre(s)
The Cambridge Structural Database
Emmanuel N. Nfor, Peter F. Asobo, Justin Nenwa, Oswald Ndi Nfor, Julius N. Njapba, Romanus N. Njong et 1 autre(s)
The Cambridge Structural Database
Justin Nenwa, Patrick L. Djonwouo, Michel M. Bélombé, Emmanuel N. Nfor, Franziska Emmerling
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Justin Nenwa, Patrick L. Djonwouo, Michel M. Bélombé, Emmanuel N. Nfor, Franziska Emmerling
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Gouet Bebga, Martin Signé, Justin Nenwa, Mohamed Mbarki, Boniface P. T. Fokwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Emmanuel N. Nfor, Peter F. Asobo, Justin Nenwa, Oswald Ndi Nfor, Julius N. Njapba, Romanus N. Njong et 1 autre(s)
International Journal of Inorganic Chemistry
Two new complexes of nickel (II) with 4-amino-3, 5-bis(pyridyl)-1, 2, 4-triazole (abpt) and iron (II) with 2-(3-phenyl-1H-pyrazole-5-yl) pyridine (phpzpy) have been synthesized and characterized by elemental analysis and IR spectroscopy. The crystal structures of the complexes have been determined by single crystal X-ray diffraction techniques. In the nickel and iron complexes, the ligands are coordinated through nitrogen atoms in bidentate manner. The ligands and their respective complexes have been tested for their antifungal activity against Aspergillus niger, Aspergillus flavus, and Candida albicans . From the study, the complexes showed enhanced activities against the tested organisms compared to the ligands.
Gouet Bebga, Martin Signé, Justin Nenwa, Mohamed Mbarki, Boniface P. T. Fokwa
Acta Crystallographica Section E Structure Reports Online
The asymmetric unit of the title solvated mol-ecular salt, (C5H6N)[Cr(C2O4)2(H2O)2]·CO(NH2)2, contains half a formula unit. Each component is completed by crystallographic twofold symmetry: in the cation, one C and the N atom lie on the rotation axis; in the anion, the Cr(III) ion lies on the axis; in the solvent mol-ecule, the C and the O atom lie on the axis. The aqua ligands are in a trans disposition in the resulting CrO6 octa-hedron. In the crystal, the components are linked by O-H⋯O, N-H⋯O and N-H⋯(O,O) hydrogen bonds, generating a three-dimensional network.
Michel M. Bélombé, Justin Nenwa, Jean S. T. Wankap Kouamo, Siméon Ponou, Andreas Fischer
Acta Crystallographica Section C Crystal Structure Communications
The crystal structure of the title compound, {[Cu(C(4)H(4)O(6))(C(2)H(6)N(4)O(2))]·4H(2)O}(n), contains the central Cu(II) cation in a distorted octahedral coordination, symmetrically chelated by the two imine N atoms of a neutral oxamide dioxime (H(2)oxado) ligand [Cu-N = 1.9829 (16) Å] and unsymmetrically bis-chelated by two halves of the L-(+)-tartrate(2-) (tart) ligands, each half being linked to the Cu(II) cation via the deprotonated carboxylate group and protonated hydroxy group [Cu-O = 1.9356 (14) and 2.4674 (13) Å, respectively]. The extended asymmetric unit is defined by twofold axes, one passing through the Cu(II) cation and the centre of the oxamide dioxime (H(2)oxado) ligand and the another two (symmetry related) bisecting the central C-C bonds of the tartrate ions. The structure is chiral, consisting of enantiomeric linear-chain polymers oriented along [001], with virtual monomeric {Cu(tart(0.5))(2)(H(2)oxado)} repeat units and with the chains interleaved face-to-face into `twin pillars'. Nanochannels exist, running parallel to the c axis and bisecting a and b, which host `double strings' of solvent water molecules. Extensive hydrogen bonding (O-H···O and N-H···O) between the chains and solvent water molecules, together with extended π-σ interactions, consolidate the bulk crystal structure.
Michel M. Bélombé, Justin Nenwa, Franziska Emmerling
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Michel M. Bélombé, Justin Nenwa, Jean S. T. Wankap Kouamo, Siméon Ponou, Andreas Fischer
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Justin Nenwa, Gouet Bebga, Stanton Martin, Michel M. Bélombé, M. Mbarki, Boniface P. T. Fokwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Justin Nenwa, Olivier Befolo, Gouet, B., M. Mbarki, Boniface P. T. Fokwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Justin Nenwa, Olivier Befolo, GOUET BEBGA, Mohamed Mbarki, Boniface P. T. Fokwa
Acta Crystallographica Section E Structure Reports Online
The title compound, (C(5)H(6)N)[Cr(C(2)O(4))(2)(H(2)O)(2)], contains one protonated pyridine mol-ecule and one [Cr(C(2)O(4))(2)(H(2)O)(2)](-) complex anion in the asymmetric unit. The Cr(III) in the complex anion is coordinated in a distorted octa-hedral environment by two O atoms from two cis water mol-ecules and four O atoms from two chelating oxalate dianions. The crystal packing is stabilized by inter-molecular N-H⋯O(oxalate) and O-H⋯O(oxalate) hydrogen bonds and by π-π stacking inter-actions (centroid-centroid distance = 3.602 Å) between pyridine rings, thereby building up a three-dimensional network.
Michel M. Bélombé, Justin Nenwa, N.A.S.N. Tchuisse, Franziska Emmerling, S. Obbade, A. Semmoud et 1 autre(s)
HAL (Le Centre pour la Communication Scientifique Directe)
The novel coordination polymer of general formula {[(H<sub>2</sub>O)Ba(<i>μ</i>-H<sub>2</sub>O)Ba(OH<sub>2</sub>)<sub>4</sub>]@ [(C<sub>2</sub>O<sub>4</sub>)<sub>2</sub>Al(<i>μ</i>-OH)<sub>2</sub>Al(C<sub>2</sub>O<sub>4</sub>)<sub>2</sub>].H<sub>2</sub>O}n (1), has been synthesized in water and characterized by FTIR spectra, elemental and thermal analyses, and by full X-ray structure determination. Compound 1 crystallizes in an interesting nonmolecular coordination network where oxalato ligands <i>μ</i>-bridge neighboring Ba(II) and Al(III) centers. The asymmetric unit of 1 consists of one cationic tri-<i>μ</i>-oxygen-bridged pseudo-dimer - formally [(H<sub>2</sub>O)Ba1(μ-H<sub>2</sub>O)Ba2(OH<sub>2</sub>)<sub>4</sub>]<sup>4+</sup> - one centrosymmetric anionic di-<i>μ</i>-hydroxido-bis[<i>cis</i>-bis(oxalato)aluminate] dimer - [(C<sub>2</sub>O<sub>4</sub>)<sub>2</sub>Al1(<i>μ</i>-OH) <sub>2</sub>Al2(C<sub>2</sub>O<sub>4</sub>)<sub>2</sub>]<sup>4-</sup> - and one solvent water molecule. The Ba<sup>2+</sup> ions in the cationic dimer are both ten-coordinate and 4.335(1) Å apart. The Al<sup>3+</sup> ions in the anionic dimer each experience distorted octahedral coordination by six O atoms, being distant by 2.854 Å in average and centered at two independent lattice positions related by the <i>P</i>2<sub>1</sub>/n space group symmetry. The anionic dimers are interconnected amongst themselves via O-H***O bridgings across the hydroxido groups into 1-D pillars that run parallel to [001]. These negatively charged pillars are tightly cross-linked <i>via</i> coordinate bonds of oxalato O atoms to the cationic Ba dimers. Coulombic interactions between the ionic motifs and extended 3-dimensional H-bonding involving solvent water molecules as well, concur to consolidate the bulk structure. Thermogravimetric analysis (TGA) shows that compound 1 is stable to heat up to 400 °C.
Michel M. Bélombé, Justin Nenwa, Yves A. Mbiangué, Felicite Majoumo‐Mbe, Peter Lönnecke, Evamarie Hey‐Hawkins
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Michel M. Bélombé, Justin Nenwa, Yves A. Mbiangué, Felicite Majoumo‐Mbe, Peter Lönnecke, Evamarie Hey‐Hawkins
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Michel M. Bélombé, Justin Nenwa, Jean Ngouné, E. Álvarez, A. Galindo
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Justin Nenwa, Michel M. Bélombé, Jean Ngouné, Boniface P. T. Fokwa
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Michel M. Bélombé, Justin Nenwa, Franziska Emmerling
Journal of Chemistry
A new proton‐transfer organic salt, quinolinium hydrogensquarate (C 13 H 9 NO 4 ), has been synthesized and fully characterized by single crystal x‐ray diffraction. The salt crystallizes in the monoclinic space group P 2 1 /n with the parameters: a = 3.8290(12) Å, b = 20.960(6) Å, c = 13.802(4) Å, β = 95.452(5) ° , V = 1102.7(6) Å3, Z = 4 formula units. The structure consists of uncommon supramolecular neutral dimers which pile up parallel to [100] forming infinite sheets. These centrosymmetric dimers are held together by lateral hydrogen‐bonds whereby two neighboring coplanar hydrogensquarate anions act as a bridge between two terminal quinolinium cations and C‐H…O bridgings interlink next neighboring sheets. The bulk structure of this salt is consolidated by weak π—π interactions within the sheets which are neatly ordered side‐by‐side relative to one another.
Michel M. Bélombé, Justin Nenwa, Peter Lönnecke, Evamarie Hey‐Hawkins
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Michel M. Bélombé, Justin Nenwa, F. Emmerling
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Michel M. Bélombé, Justin Nenwa, Boniface P. T. Fokwa, R. Dronskowski
The Cambridge Structural Database
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Michel M. Bélombé, Justin Nenwa, Boniface P. T. Fokwa, Richard Dronskowski
Zeitschrift für Kristallographie - New Crystal Structures
Article Crystal structure of catena- bis[aqua-μ-(2S,3S)-tartratocobalt(II)]trihydrate,[Co(H2O)(C4H4O6)]2·3H2O, a new polymorph was published on April 1, 2009 in the journal Zeitschrift für Kristallographie - New Crystal Structures (volume 224, issue 1-4).
Michel M. Bélombé, Justin Nenwa, Boniface P. T. Fokwa, Richard Dronskowski
Zeitschrift für Kristallographie - New Crystal Structures
Article Crystal structure of catena-bis[aqua-μ-(2S,3S)-tartratocobalt(II)] trihydrate, [Co(H2O)(C4H4O6)]2 · 3H2O, a new polymorph was published on June 1, 2009 in the journal Zeitschrift für Kristallographie - New Crystal Structures (volume 224, issue 2).
Michel M. Bélombé, Justin Nenwa, Franziska Emmerling
Zeitschrift für Kristallographie - New Crystal Structures
Article Crystal structure of quinolinium trans-diaquabis(oxalato-0,0')- chromate(III), [C9H8N][Cr(H2O)2(C2O4)2] was published on April 1, 2009 in the journal Zeitschrift für Kristallographie - New Crystal Structures (volume 224, issue 1-4).
Michel M. Bélombé, Justin Nenwa, Franziska Emmerling
Zeitschrift für Kristallographie - New Crystal Structures
Article Crystal structure of quinolinium trans-diaquabis(oxalato-O,O′)- chromate(III), [C9H8N][Cr(H2O)2(C2O4)2] was published on June 1, 2009 in the journal Zeitschrift für Kristallographie - New Crystal Structures (volume 224, issue 2).
Michel M. Bélombé, Justin Nenwa, Yves-A. Mbiangué, Felicite Majoumo‐Mbe, Peter Lönnecke, Evamarie Hey‐Hawkins
Dalton Transactions
Compound (H(3)oxado)[Co(H(2)oxado)(3)](SO(4))(2).2H(2)O () (H(3)oxado(+) = oxamide dioximemonoximium) reacted metathetically with Ba(6)(H(2)O)(17)[Cr(C(2)O(4))(3)](4).7H(2)O in water to give the one-dimensional complex salt {[Co(H(2)oxado)(3)][Cr(C(2)O(4))(3)].5H(2)O}(infinity) () (H(2)oxado = oxamide dioxime). Compounds and were characterized by elemental analysis, FTIR, UV-Vis and by single crystal X-ray structure determination. The structure of consists of infinite pillars of alternating chiral complex cations and anions linked together along [100] by electrostatic and longitudinal O-HO interactions, with an average intrachain CoCr separation of 4.94 A. Equatorial N-HO bridges cross-link neighboring pillars (which are of opposite chirality) and consolidate a three-dimensional lattice framework which delineates elliptic nanochannels parallel to the a axis, encapsulating highly disordered water molecules. The thermal stability of both compounds was assessed by TGA, and the effective magnetic moment of , checked at room temperature, revealed considerable spin-orbit coupling.
Michel M. Bélombé, Justin Nenwa, Peter Lönnecke, Evamarie Hey‐Hawkins
Zeitschrift für anorganische und allgemeine Chemie
Abstract Co(OAc) 2 reacts with oxamide dioxime (H 2 oxado) in water in the presence of ClO 4 – ions to produce [Co(Hoxado) 2 (H 2 oxado)]ClO 4 · 6H 2 O ( 1 ), where Hoxado – is the anion of H 2 oxado, derived from the deprotonation of one of the two hydroximinic groups, and in which oxidation of Co II to Co III (in air) had occurred. 1 is the first example of a salt in which the cation, [Co(H 2 oxado) 3 ] 3+ , is doubly deprotonated to generate the chiral cation, [Co(Hoxado) 2 (H 2 oxado)] + . The central cobalt cation is pseudo‐octahedrally coordinated by six nitrogen atoms. In the solid state, the complex cations form centro‐symmetric dimers via O–H ··· O bridges. The bulk structure is consolidated by an extended three‐dimensional network of O–H ··· O and N–H ··· O bridges that interconnect the ionic constituents and the water molecules.
Michel M. Bélombé, Justin Nenwa, Evamarie Hey‐Hawkins, Peter Lönnecke, Peter Strauch, Klaus R. Koch
Polyhedron
Michel M. Bélombé, Justin Nenwa, Yves A. Mbiangué, Boniface P. T. Fokwa, Richard Dronskowski
Acta Crystallographica Section E Structure Reports Online
The asymmetric unit of the title compound, [Ni(C(2)H(6)N(4)O(2))(3)]SO(4)·5H(2)O, contains two complex cations, two sulfate anions and ten lattice water mol-ecules. In both independent cations, the central Ni(II) ion adopts a distorted octa-hedral coordination involving six imino N atoms of three bidentate oxamide dioxime ligands. The bulk structure is achieved by a three-dimensional network of O-H⋯O and N-H⋯O hydrogen bonds which inter-link the ionic partners and some water mol-ecules in such a manner that the lattice framework thus formed defines channels parallel to [100]. The other water mol-ecules are lodged inside these channels. Two of the ten water mol-ecules in the asymmetric unit are disordered over three sites, in 0.356 (3):0.324 (5):0.320 (5) and 0.247 (3):0.293 (6):0.460 (6) occupancy ratios, and one O atom of a sulfate ion is also disordered over two sites, with occupancies of 0.621 (5) and 0.379 (5).
Justin Nenwa, Michel M. Bélombé, Boniface P. T. Fokwa, Richard Dronskowski
Acta Crystallographica Section E Structure Reports Online
A monoclinic polymorph of the title compound, {[BaCu(C(2)O(4))(2)(H(2)O)(5)]·H(2)O}(n), is reported. The structure is best described as a coordination polymer where the Cu(II) and Ba(II) centers are coordinated by five and nine O atoms, respectively, in capped quadratic antiprismatic and tetragonal pyramidal geometries. The polymerization arises due to the presence of bridging mono- and bidentate oxalate ligands as well as bridging water mol-ecules. The crystal structure is consolidated by a three-dimensional network of hydrogen bonding.
Michel M. Bélombé, Justin Nenwa, Yves-A. Mbiangué, Gouet Bebga, Felicite Majoumo‐Mbe, Evamarie Hey‐Hawkins et 1 autre(s)
Inorganica Chimica Acta
Michel M. Bélombé, Justin Nenwa, Astride L. Kammoe, Pierre F. P. Poudeu
Acta Crystallographica Section E Structure Reports Online
The title compound, (H3O)[Ni(C2H6N4O2)3]I3 or (H3O)[Ni(H2oxado)3]I3, where H2oxado = oxamide dioxime, contains six [Ni(H2oxado)3]2+ cations, six H3O+ cations and eighteen I− anions in the unit cell. The Ni atom lies on a position of site symmetry 32 and the hydronium cation is disordered on a position of site symmetry \overline{3}. The crystal packing is consolidated by O—H⋯O hydrogen bonds that link the cations along c into positively charged pillars. The proton balancing the charge of the iodide ions is attached to the water molecule of crystallization, thus forming a hydronium ion.
Michel M. Bélombé, Justin Nenwa, Astride L. Kammoe, Pierre F. P. Poudeu
Michel M. Bélombé, Justin Nenwa, Boniface P. T. Fokwa, Richard Dronskowski
Acta Crystallographica Section E Structure Reports Online
The title compound, K[Cr(C2O4)2(H2O)2], was crystallized from an aqueous solution. It is the first member without uncoordinated water molecules of formula Am[M(C2O4)2(H2O)2]·xH2O, where A = monovalent cation, m = 1 or 2, M = metal(II) or metal(III), x ≥ 0. The crystal packing is governed by electrostatic and coordinative interactions, and intermolecular hydrogen bonds help to stabilize the packing. The coordination of the Cr sites is quasi-octahedral, and the K ions are eight-coordinated by O atoms of oxalate ligands, forming strongly distorted square antiprisms.
Michel M. Bélombé, Justin Nenwa, Mbiangue Y-A, Germain Evina Nnanga, Mbomekalle I-M, Evamarie Hey‐Hawkins et 2 autre(s)
Dalton Transactions
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