title: N-heterocycle chelated oxomolybdenum(VI and V) complexes with bidentate citrate.
abstract: A 1,10-phenanthroline (phen) chelated molybdenum(VI) citrate, [(MoO2)2O(H2cit)(phen)(H2O)2] x H2O (1) (H4cit = citric acid), is isolated from the reaction of citric acid, ammonium molybdate and phen in acidic media (pH 0.5-1.0). A citrato oxomolybdenum(V) complex, [(MoO)2O(H2cit)2(bpy)2] x 4H2O (2), is synthesized by the reduction of citrato molybdate with hydrazine hydrochloride in the presence of 2,2'-bipyridine (bpy), and a monomeric molybdenum(VI) citrate [MoO2(H2cit)(bpy)] x H2O (6) is also isolated and characterized structurally. The citrate ligand in the three neutral compounds uses the alpha-alkoxy and alpha-carboxy groups to chelate as a bidentate leaving the two beta-carboxylic acid groups free, that is different from the tridentate chelated mode in the citrato molybdate(VI and V) complexes. 1 and in solution show obvious dissociation based on 13C NMR studies.
authors.affiliation: State Key Laboratory for Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China. zhzhou@xmu.edu.cn
authors.forename: Zhao-Hui
authors.initials: ZH
authors.lastname: Zhou
authors.forename: Can-Yu
authors.initials: CY
authors.lastname: Chen
authors.forename: Ze-Xing
authors.initials: ZX
authors.lastname: Cao
authors.forename: Khi-Rui
authors.initials: KR
authors.lastname: Tsai
authors.forename: Yuan L
authors.initials: YL
authors.lastname: Chow
mesh_terms: D002614:Chelating Agents / Q000737:chemistry*; D019343:Citric Acid / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006571:Heterocyclic Compounds / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D008982:Molybdenum / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry*
chemical_list: D002614:Chelating Agents; D006571:Heterocyclic Compounds; C044659:molybdate; D019343:Citric Acid; D008982:Molybdenum; D010100:Oxygen