文摘
The reaction of Na(OSip>tp>Bu2Me) with CrCl3 yields solid [Cr(OSip>tp>Bu2Me)3]n (1), which can be crystallized in the presence of excess Na(OSip>tp>Bu2Me) to yield [Na(THF)][Cr(OSip>tp>Bu2Me)4] (2). This complex is oxidized to yield Cr(OSip>tp>Bu2Me)4 (3), a crystalline chromium(IV) siloxide complex that is air- and moisture-stable. Electronic spectroscopic analysis of the absorption spectrum of 3 indicates a particularly weak ligand field (螖T = 7940 cmp>鈥?p>) and covalent Cr鈥揙 bonding. 3 provides the first structural and spectroscopic characterization of a homoleptic chromium(IV) siloxide complex and provides a benchmark for tetrahedral chromium(IV) ions residing in solid oxide lattices.