Organic-inorganic hybrid materials of the copper molybdate family. Syntheses and structures of [Cu(tpa)Mo₂O₇], [Cu(Me₂bpy) Mo₂O₇] and [Cu(<i>t</i>-Bu₂bpy)Mo₄O₁₃] (tpa = tri-2-pyridylamine, Me₂bpy = 5,5'-dimethyl-2,2'-bipyridine, <i>t</i>-Bu₂bpy = 4,4'-di-<i>tert</i>-butyl-2,2'-bipyridine)

Abstract

2235-2243The hydrothermal react ions of CuSO4 • 5H2O and MoO3 in the presence of various sterically hindered polypyridyl ligands have been studied. Under basic conditions, [Cu(tpa)Mo2O7], (1) and [Cu(Me2bpy) Mo2O7] (2) are formed, while under mildly acidic conditions. [Cu(t-Bu2bpy) Mo4O13)(4) is the product. The structures of 1 and 2 are grossly similar in that both are constructed from molybdate chains decorated with secondary metal -ligand coordination cation subunits. In the case of 1, the molybdate chain consists of alternating pairs of edge-sharing octahedra and square pyramids, while for 2, the chain exhibits corner-sharing octahedra with peripheral tetrahedral sites. The profound structural influences of hydrothermal reaction conditions such as pH are dramatically illustrated by the structure of 4 which consists of octamolybdate clusters linked through binuclear {Cu2(t-Bu2bpy)2}4+ sites