Fokwa Group

2013

• M. Mbarki, R. St. Touzani, B. P. T. Fokwa: Nb₂OsB₂ with a New Twofold Superstructure of the U₃Si₂ Type: Synthesis, Crystal Chemistry and Chemical Bonding. J. Solid State Chem. 2013, doi.org/10.1016/j.jssc.2013.04.018.

• B. Gouet, I. M. Ndassa, P. R. Ndong, P. R. N. Misse, B. P. T. Fokwa: Crystal structure of potassium trans-diaquabis[oxalato-k²O,O] chromate(III) urea disolvate,  K[Cr(C₂O₄)₂(H₂O)₂]·2CO(NH₂)₂, C₆H₁₂CrKN₄O₁₂, Z. Kristallogr. NCS 2013,doi:10.1524/ncrs.2013.0069.

• I. M. Ndassa, M. Gillessen, B. P. T. Fokwa: Electronic Structure, Chemical Bonding and Magnetism of the Metal-Rich Borides MRh₆B₃ (M = Cr, Mn, Fe, Co, Ni) with Th₇Fe₃-Type Structure: A Density Functional Theory Study,  Solid State Sciences. 2013, 17, 14.

• C. Goerens, B. P. T. Fokwa: V_1+xNb_1–xIrB₂ (x ≈ 0.1), The First Quaternary Metal-Rich Boride Adopting The Mo₂IrB₂-Type Structure: Synthesis, Crystal and Electronic Structure and Bonding Analysis, Z. Anorg. Allg. Chem. 2013, doi: 10.1002/zaac.201200439.

2012

• B. P. T. Fokwa, M. Hermus: All-Boron Planar B₆ Ring in the Solid State Phase Ti₇Rh₄Ir₂B₈, Angew. Chem. 2012, DOI: 10.1002/ange.201106798 and Angew. Chem. Int. Ed. 2012, DOI: 10.1002/anie.201106798. Highlighted in Chemical and Engeneering News (02/2012).

• M. Hermus, B. P. T. Fokwa: Competing Electronic and Size Effects When Substituting 3d Elements for Nb in Nb₃Ru₅B₂ En Route to the Quaternary Phases (Nb_2–xSc_x)^4gNb^2aRu₅B₂ (1 ≤ x < 2), Nb_3–xM_xRu₅B₂ (M = Ti, V; x ≈ 1), and Nb_2+xM_1–xRu₅B₂ (M = Cr, Mn, Fe, Co, Ni; 0 < x ≤ 0.5), Eur. J. Inorg. Chem. 2012, doi: 10.1002/ejic.201200627.

• C. Goerens, B. P. T. Fokwa: The complex metal-rich boride Ti_1+xRh_2−x+yIr_3−yB₃ (x=0.68, y=1.06) with a new structure type containing B₄ zigzag fragments: Synthesis, crystal chemistry and theoretical calculations,  J. Solid State Chem. 2012, doi.org/10.1016/j.jssc.2012.04.005.

• P. R. N. Misse, M. Mbarki, B. P. T. Fokwa: Synthesis, crystal structure investigation and magnetism of the complex boride series Cr_x(Rh_1−yRu_y)_7−xB₃ (x=0.88 − 1, y = 0 − 1) with Th₇Fe₃−type structure   J. Solid State Chem. 2012, doi.org/10.1016/j.jssc.2012.04.041.

• V. L. Deringer, C. Goerens, M. Esters,  R. Dronskowski, B. P. T. Fokwa: Chemical Modeling of Mixed Occupations and Site Preferences in Anisotropic Crystal Structures: Case of Complex Intermetallic Borides. Inorg. Chem. 2012, doi/abs/10.1021/ic300023t.

• J. Nenwa, B. Gouet, M. Signé, M. M. Bélombé,  M. Mbarki, B. P. T. Fokwa: 2-Aminopyridinium trans -diaquabis[oxalato(2−)-κ²O¹,O²]chromate(III), Acta Cryst. E38, 2012,  m1325.

• J. Nenwa, O. Befolo, B. Gouet, M. Mbarki, B. P. T. Fokwa: Pyridinium cis -diaquabis[oxalato(2−)-κ²O¹,O²]chromate(III), Acta Cryst. E38, 2012,  m1434.

• J. Nenwa, B. Gouet, P. L. Djonwouo, B. P. T. Fokwa: Synthesis, X-ray structure and spectroscopic characterization of a non-stoichiometric nanostructured silver salt hosting water-guest molecules. Res. J. Chem. Environ. 2012, 16, 111.

• B. Gouet, Y.A. Mbiangué, J. Nenwa, B. P. T. Fokwa: Synthesis and X-ray structures of two acidic cobalt (III) complex salts based on oxamide dioxime ligand system. Res. J. Chem. Environ. 2012, 16, 7.

• M.M. Bélombé, J. Nenwa, N.A.S.N. Tchuisse, F. Emmerling, S. Obbade, A. Semmoud, B.P.T. Fokwa : Synthesis, crystal structure and thermal stability of the novel coordination polymer of general formula: {[(H₂O)Ba(μ-H₂O)Ba(OH₂)₄]@[(C₂O₄)₂Al(μ-OH₂Al(C₂O₄)₂].H₂O}n. ScienceJet 2012, 1, 24.

2011

• M. Hermus, D. Geier, B. P. T. Fokwa: Nb₃Ru₅B₂ – The First Fully Characterized Ternary Phase in the Nb-Ru-B System: Synthesis, Crystal Structure, and Bonding Analysis. Z. Anorg. Allg. Chem. 2011, DOI:10.1002/zaac.201100374.

• P. R. N. Misse, M. Gilleßen, B. P. T. Fokwa:Site-Preferential Design of Itinerant Ferromagnetic Borides: Experimental and Theoretical Investigation of MRh₆B₃ (M = Fe, Co). Inorg.Chem. 2011,DOI:10.1021/ic2013655.

• C. Goerens, J. Brgoch,  G. J. Miller, B. P. T. Fokwa: Scaffolding, Ladders, Chains, and Rare Ferrimagnetism in Intermetallic Borides: Synthesis, Crystal Chemistry and Magnetism. Inorg. Chem. 2011,DOI: 10.1021/jic200668j.

• P. R. N. Misse, R. Dronskowski, B. P. T. Fokwa:Site-Preferential Design of Itinerant Ferromagnetic Borides: Experimental and Theoretical Investigation of MRh6B3 (M = Fe, Co). Z.Naturforsch. 2011, 66b, 1241.

• B. P. T. Fokwa, H.Lueken, R. Dronskowski: Rational Design of Complex Borides – One-Electron-Step Evolution from Soft to Semi-Hard Itinerant Ferromagnets in the New Boride Series Ti₂FeRu_5–nRh_nB₂ (1 ≤ n ≤ 5). Eur. J. Inorg. Chem. 2011, doi: 10.1002/ejic.201100315.

• B. P. T. Fokwa, M. Hermus: Complete Titanium Substitution by Boron in a Tetragonal Prism: Exploring the Complex Boride Series Ti_3−xRu_5−yIr_yB_2+x (0 ≤ x ≤ 1 and 1 < y < 3) by Experiment and Theory. Inorg. Chem. 2011,DOI: 10.1021/ic102148x.

• J. Brgoch, C. Goerens, B. P. T. Fokwa, G. J. Miller: Scaffolding, Ladders, Chains, and Rare Ferrimagnetism in Intermetallic Borides: Electronic Structure Calculations and Magnetic Ordering. J. Am. Chem. Soc. 2011, DOI: 10.1021/ja200909r.

• M. Hermus, B. P. T. Fokwa:Synthesis, Crystal Structure, and Ru/Ir Site Preference in the Complex Boride Series Ti₂FeRu_5–xIr_xB₂ and Zr₂Fe_1–δRu_5–x+δIr_xB₂ (x = 1–4, δ < 0.15). Z. Anorg. Allg. Chem. 2011, DOI:10.1002/zaac.201100024.

2010

• B. P. T. Fokwa: Transition Metal-Rich Borides: Fascinating Crystal Structures and Magnetic Properties, Invited Microreview, Eur. J. Inorg. Chem. 2010, doi: 10.1002/ejic.201000116.

• M. Hermus, B. P. T. Fokwa: Zr₂Ir₆B with an eightfold superstructure of the cubic perovskite-like boride ZrIr₃B_0.5: Synthesis, crystal structure and bonding analysis, J. Solid State Chem. 2010, doi:10.1016/j.jssc.2010.01.026.

• P. R. N. Misse, B. P. T. Fokwa: Synthesis, Characterization, and Magnetic Properties of the New Boride Solid Solutions M_0.5Ru_6.5B₃ (M = Cr, Mn, Co, Ni), Z. Anorg. Allg. Chem. 2010, 10.1002/zaac.200900569.

• B. P. T. Fokwa, C. Goerens, M. Gilleßen: New quaternary complex borides, Ti₉M₂Ru₁₈B₈ (Cr, Mn, Co, Ni, Cu, Zn): synthesis, crystal structure and bonding analysis, Z. Kristallogr. 2010, doi:10.1524/zkri.2010.1239.

• K. Tschulik,  S. Hoffmann, B. P. T. Fokwa, M. Gilleßen, P. Schmidt: Studies regarding the homogeneity range of the zirconium phosphide telluride Zr_2+δPTe₂, Solid State Sciences. 2010, 12, 2030.

• J. Nenwa, M. M. Bélombé,  J Ngoune, B. P. T. Fokwa: 4-(Dimethylamino)pyridinium trans -diaquabis[oxalato(2−)-κ²O¹,O²]chromate(III), Acta Cryst. 2010, E66, m1410.

• M. M. Bélombé, J. Nenwa, O. T. Tene, B. P. T. Fokwa: Synthesis, X-ray structure and thermal behavior of isomorphous silver-deficient channel lattice frameworks with general formula [(Ag_0.25/M_0.25)(H₂O)]@[Ag₂M(C₂O₄)₃].4H₂O (M = Co^III, Cr^III), Global. J. Inorg. Chem. 2010, 1, 34.

2009

• B. P. T. Fokwa: Structure-Property-Relationships in new Metal-rich Borides, Habilitation Thesis,  RWTH Aachen University, 2009.

• B. P. T. Fokwa: Valence-Electron-Driven Ru/Ti Site Preference in the New Ternary Boride Ti₁₀Ru₁₉B₈: Synthesis and Single-Crystal Structure Refinement, Z. Anorg. Allg. Chem. 2009, 635, 2258.

• B. P. T. Fokwa, P. R. N. Misse, M. Gilleßen, R. Dronskowski: Sn-flux Syntheses, Characterizations and Bonding Analyses of OsB and TiB₂, J. Alloys Compd. 2009 DOI:10.1016/j.jallcom.2009.09.125
  

• L Stork, X. Liu, B. P. T. Fokwa, R. Dronskowski:  [CrBr₂(NH₃)₄][CrBr₄(NH₃)₂], a new chromium(III) complex, Acta Cryst. 2009, C65, i54.

• K. Tschulik, M. Ruck, M. Binnewies, E. Milke, S. Hoffmann, W. Schnelle, B. P. T. Fokwa, M. Gilleßen, P. Schmidt: Chemistry and Physical Properties of the Phosphide Telluride Zr₂PTe₂, Eur. J. Inorg. Chem. 2009, 3102.

• M. M. Bélombé, J. Nenwa, Y. A. Mbiangue, B. P. T. Fokwa, R. Dronskowski: Crystal structure of catena-bis[aqua-μ-(2S,3S)-tartratocobalt(II)] trihydrate, [Co(H₂O)(C₄H₄O₆)]₂ · 3H₂O, a new polymorph, Z. Kristallogr. NCS 2009, 224, 241.

2008

• B. P. T. Fokwa, G. D. Samolyuk, G. J. Miller, R. Dronskowski: Ladders of a magnetically active element in the structure of the novel complex boride Ti₉Fe₂Ru₁₈B₈: Synthesis, structure, bonding and magnetism, Inorg. Chem. 2008, 47, 2113. Highlighted in Nachrichten aus der Chemie (03/2009).
  

• B. P. T. Fokwa, R. Dronskowski: New transition-metal-borides containing trigonal-planar B₄-units: Synthesis and single-crystal structure analyses of Ti_1.6Os_2.4B₂ and Ti_1–xFe_xOs₂RhB₂ (0 ≤ x < 0.5), Z. Anorg. Allg. Chem. 2008, 634, 1955.

• D. Sendor, B. P. T. Fokwa, R. Dronskowski, U. Simon: Electrical and optical properties of Cetineite-Type Rb-, Sr-, and Ba-oxoselenoantimonates(III), Eur. J. Inorg. Chem. 2008, 369.

• M. M. Bélombé, J. Nenwa, Y. A. Mbiangue, B. P. T. Fokwa, R. Dronskowski: Tris (oxamide dioxime-κ²N,N^’)nickel(II) sulfate pentahydrate, Acta Cryst. 2008, E64, m1440.

• M. M. Bélombé, J. Nenwa, B. Gouet, B. P. T. Fokwa, R. Dronskowski: Di[tris(oxamide dioxime-κ²N,N^’)cobalt(III)] oxalate disulfate dodecahydrate, Acta Cryst. 2008, E64, m116.

2007

• B. P. T. Fokwa, H. Lueken, R. Dronskowski: Chemical tuning between ferro-magnetism and antiferromagnetism in the complex boride series Sc₂FeRu_5–nRh_nB₂ (0 ≤ n ≤ 5), Chem. Eur. J. 2007, 13, 6040.
  

• G. Samolyuk, B. P. T. Fokwa, R. Dronskowski, G. J. Miller: Electronic structure, chemical bonding and magnetic properties in the intermetallic series Sc₂Fe(Ru_1–xRh_x)₅B₂ from first principles, Phys. Rev. B. 2007, 76, 094404.

• D. Sendor, B. P. T. Fokwa, R. Dronskowski, U. Simon: Noble gases affect the conductivity of cetineite-type nanoporous semiconductors, Angew. Chem. Int. Ed. 2007, 46, 6372; Angew. Chem. 2007, 119, 6491.

• L Stork, X. Liu, B. P. T. Fokwa, R. Dronskowski: Crystal structure determination of thallium carbodiimide, Tl₂NCN, Z. Anorg. Allg. Chem. 2007, 633, 1339.

• M. M. Bélombé, J. Nenwa, B. Gouet, B. P. T. Fokwa, R. Dronskowski: Di[tris(oxamide dioxime-κ²N,N^’)cobalt(III)] oxalate bis(sulfate) dodecahydrate, Acta Cryst. 2007, E63, m2037.

• M. Krott, X.Liu, B. P. T. Fokwa, M. Speldrich H. Lueken, R. Dronskowski: Synthesis, crystal structure determination and magnetic properties of two novel transition metal carbodiimides: CoNCN and NiNCN, Inorg. Chem. 2007, 2204.

• Th. Doert, E. Dashjav, B. P. T. Fokwa: The rare earth metal polyselenides Gd₈Se₁₅, Tb₈Se_15–x, Dy₈Se_15–x, Ho₈Se_15–x, Er₈Se_15–x, and Y₈Se_15–x - Increasing disorder in defective planar selenium layers, Z. Anorg. Allg. Chem. 2007, 633, 261.

• B. P. T. Fokwa, R. Dronskowski: Synthesis, single crystal structure refinement and Fe/T site preference in the ternary borides, Fe_xT_7–xB₃ (T = Ru, Rh; 0 < x < 1.5), J. Alloys Compd. 2007, 428, 84.

2002-2006

• B. P. T. Fokwa, J. von Appen, R. Dronskowski: Synthesis of a missing structural link: The first trigonal planar B₄ units in the novel complex boride Ti_1+xOs_2–xRuB₂ (x = 0.6), Chem. Commun. 2006, 4419. Highlighted in Nachrichten aus der Chemie (03/2007).

• M. M. Bélombé, J. Nenwa, B. P. T. Fokwa, R. Dronskowski: Potassium trans diaquabis[oxalato(2-)-κ²O,O']chromate(III), Acta Cryst. 2006, E62, m1400.

• B. P. T. Fokwa, B. Eck, R. Dronskowski: Ti₂Rh₆B - A new boride with a double perovskite-like structure containing octahedral Rh₆ clusters, Z. Kristallogr.2006, 221, 445.

• B. P. T. Fokwa, R. Dronskowski: Synthesis, crystal structure determination and Fe/Rh site preference in the new ternary boride FeRh₆B₃, Z. Anorg. Allg. Chem. 2005, 631, 2478.

• W. Liao, B. P. T. Fokwa, R. Dronskowski: Eu₈(NCN)_5–dI_6+2d (d = 0.05): a novel rare-earth carbodiimide iodide containing oligomeric tritetrahedral Eu₈ clusters, Chem. Commun. 2005, 3612.

• B. P. T. Fokwa, Th. Doert: The ternary rare-earth polychalcogenides LaSeTe₂, CeSeTe₂, PrSeTe₂, NdSeTe₂, and SmSeTe₂: Syntheses, crystal structures, electronic properties, and charge-density- wave-transitions, Solid State Sciences. 2005, 7, 573.

• Th. Doert, B. P. T. Fokwa, S. Lidin, F. J. Garcia Garcia: Site occupancy wave and charge density waves in the modulated structure of Nd_0.6Gd_0.4Se_1.85, J. Solid State Chem. 2004, 177, 1598.

• Th. Doert, B. P. T. Fokwa, P. Simon, S. Lidin, T. Söhnel: LaSeTe₂ – Temperature dependent structure investigation and electron holography on a charge density waves hosting compound, Chem. Eur. J. 2003, 9, 5865.

• B. P. T. Fokwa, Th. Doert, P. Simon, T. Söhnel, P. Böttcher: PrSeTe₂, an ordered ternary polychalcogenide with the NdTe₃-structure, Z. Anorg. Allg. Chem. 2002, 628, 2612.