New Series of Oxalato-Gallophosphate Structures Containing Transition Metal Centers

Five organic−inorganic hybrid mixed-metal oxalatophosphates, (C 3 H 12 N 2 ) 2 [(VO) 2 (ox)Ga 2 (PO 4 ) 4 ] ( 1 ), (C 10 H 28 N 4 )[(VO) 2 (ox)Ga 2 (PO 4 ) 4 ]·2H 2 O ( 2 ), (C 7 H 21 N 3 ) 0.5 (H 3 O)[Mn(H 2 O) 2 Ga 4 F 2 (ox)(PO 4 ) 4 ]·4H 2 O ( 3 ), (C 5 H 14 N 2 )[Mn(H 2 O) 2 Ga 4 F 2 (ox)(PO 4 ) 4 ]·3H 2 O ( 4 ), and (C 4 H 16 N 3 )[MnGa 2 (ox) 2 (HPO 4 ) 2 (PO 4 )] ( 5 ) (ox = C 2 O 4 2 - ), 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 Mn [6p] O 6 trigonal prism and a GaO 6 octahedron, and unique trimeric polyhedral Mn(H 2 O) 2 (GaF) 2 O 12 and MnGa 2 O 16 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 Mn 2+ 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.