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 Li2[OPO] with SnCl4 in THF at -35 degrees C produced [OPO]SnCl2(THF) as a THF adduct. Addition of SnCl4 to a THF solution of H2[OPO] 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 Li2[OPO] 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.