Isolation and Structural Characterization of Tetra-<i>n</i>-propyl Zirconate in Hydrocarbon Solution and the Solid State

Abstract

Tetra-n-propyl zirconate has been purified by vacuum distillation and isolated as an extremely moisture sensitive, crystalline solid. According to a single-crystal X-ray diffraction study, crystalline tetra-n-propyl zirconate is composed of tetrameric Zr4(OPrn)16 (1) molecules whose Zr4O16 metal−oxygen core structure has virtual C2h symmetry, the same structure observed previously for n-alkyl orthotitanates. Carbon-13 NMR spectroscopic data indicate that this core structure is retained in hydrocarbon solution. Molecule 1 has the same M4O16 metal−oxygen core structure as [CH3C(CH2O)3]2M4(OPri)10, M = Ti, where the metal centers have octahedral coordination geometry, but a metal−oxygen core structure different from that of the M = Zr case, where trigonal metaprismatic coordination geometry is observed