Influences of secondary metal–ligand subunits on molybdenum oxide structures: the hydrothermal syntheses and structures of [M(tpytrz)2Mo4O13] (M = Fe, Co, Ni, Zn; tpytrz = tripyridyltriazine), [Ni(tpytrz)Mo2O7] and [Zn2(tpytrz)Mo2O8]

The hydrothermal reactions of the appropriate salts of the first row transition metal dipositive cations M′(II), MoO3 and 2,4,6-tri(4-pyridyl)-1,3,5-triazine (tpytrz) yielded the bimetallic oxide hybrid solids [M′(tpytrz)2Mo4O13] [M′ = Fe (1), Co (2), Ni (3), Zn (4)], [Ni(tpytrz)Mo2O7] (6) and [Zn2(tpytrz)Mo2O8] (7) and the molecular compound [Ni(H2O)4(Htpytrz)2][Mo8O26]·1.2H2O (5·1.2H2O). The isomorphous series 1–4 exhibits a two-dimensional bimetallic oxide network constructed from chains of corner-sharing Mo(VI) octahedra and tetrahedra, linked by {M′O4N2} octahedra. The inorganic layers are tethered by bidentate tpytrz ligands, each of which bonds to an M′ site of one layer and an octahedral {MoO5N} site of an adjacent layer, with one pyridyl group adopting a pendant mode in the interlamellar region. In contrast, the structure of [Ni(tpytrz)Mo2O7] (6), while adopting the prototypical motif of alternating bimetallic oxide networks and bridging ligand domains, is characterized by an oxide layer constructed from bimolybdate units {Mo2O7}2− linked through {NiO4N2} octahedra. Curiously, the {Zn2Mo2O8} network of [Zn2(tpytrz)Mo2O8] (7) is constructed from {MoO4} tetrahedra linked through binuclear units of edge-sharing {ZnO4N} square pyramids.