Biphenolate phosphine complexes of tin(IV)

The preparation and structural characterization of tin(IV) complexes supported by (2,2'-phenylphosphino)bis(4,6-di-tert-butylphenolate) (OPO]2-) are described. The reaction of in-situ prepared Li2OPO] with SnCl4 in THF at -35 degrees C produced OPO]SnCl2(THF) as a THF adduct. Addition of SnCl4 to a THF solution of H2OPO] in the presence of 2 equiv of NEt3 at room temperature led to the formation of the "ate" complex {OPO]SnCl3}(HNEt3). The metathetical reactions of Li2OPO] with R2SnCl2 (R=Me, n-Bu) in THF at -35 degrees C generated the corresponding five-coordinate dialkyl complexes OPO]SnR2. In addition to the multinuclear NMR spectroscopic data for all new compounds, X-ray structures of OPO]SnCl2(THF), OPO]SnMe2, and OPO]Sn(n-Bu)2 are presented.