New series of oxalato-gallophosphate structures containing transition metal centers

Five organic-inorganic hybrid mixed-metal oxalatophosphates, (C3H12N2)(2)[(VO)(2)(ox)Ga-2(PO4)(4)] (1), (C10H28N4)[(VO)(2)(ox)Ga-2(PO4)(4)].2H(2)O (2), (C7H21N3)(0.5)(H3O)[Mn(H2O)(2)Ga4F2(ox)(PO4)(4)].4H(2)O (3), (C5H14N2)[Mn(H2O)(2)Ga4F2(ox)(PO4)(4)].3H(2)O (4), and (C4H16N3)[MnGa2(ox)(2)(HPO4)(2)(PO4)] (5) (ox = C2O42-), with varied framework topologies, have been synthesized under mild hydrothermal conditions and characterized by single-crystal X-ray diffraction, magnetic susceptibility, and TG analysis. They provide foremost examples of organic-metallophosphate hybrid frameworks that contain hetero metal centers, owing to which the structures of 1-5 are able to be indexed into a series. The vanadium compounds 1 and 2 are layered, whereas the manganese compounds 3, 4, and 5, compositionally and structurally related to 1 or 2, are 3D materials. The oxalate anion can act as a bis-bidentate ligand in all five compounds as well as a monobidentate ligand in 5. Besides homo bioctahedral units of M-2'(ox)O-6 (M' = (VO) for 1 and 2, (GaF) for 3 and 4), we observe the first hetero chelating MnGa(ox)O-8 unit, formed of an unusual (MnO6)-O-[6p] trigonal prism and a GaO6 octahedron, and unique trimeric polyhedral Mn(H2O)(2)(GaF)(2)O-12 and MnGa2O16 units. The fundamental frameworks for 1-5 effectively display a series that is constructed from a substructure of 1D or 2D plus a four-ring linker and/or Mn2+ ions into 2D or 3D structures. The hetero metals have imposed magnetic property to the Ga(ox)PO lattices and led to the first well-defined M-X-Ga (X = O, F) bonds ever observed in the metal phosphate chemistry.