Diphenylantimony(V) oxo/chloro carboxylates and phosphinates: crystal structures of {SbPh2Cl[O2P(C6H11)2]}2O and [SbPh2(O2CPh)2]2O
Abstract
Reaction of SbPh2Cl3(1 mol) with the silver salt of dicyclohexylphosphinic acid (2 mol) afforded {SbPh2Cl[O2P(C6H11)2]}2O 1; a similar reaction with AgO2P(C8H15)2 gave a product formulated as {SbPh2Cl[O2P(C8H15)2]}2O 2. Similar reactions with silver carboxylates (1 : 3 stoichiometry) led to the crystalline derivatives [SbPh2(O2CR)2]2O (R = Ph 3, CHPh24, 2,4,6-Me3C6H25, 2-MeC6H46 or 4-MeC6H47), whereas the 1 : 2 reaction afforded crystalline SbPh2Cl(O2CR)2(R = Ph 8, 2-MeC6H49 or 4-MeC6H410). Interconversion of the previously known compounds [SbPh2(O2CMe)2]O and Sb4Ph8O6·3MeCO2H was achieved and established by 1H NMR spectroscopy. Compounds 1 and 3 were further characterized by X-ray diffraction; the antimony in 1 is six-co-ordinated with bridging phosphinates whereas in 3 it is seven-co-ordinated with chelating benzoates. Short Sb–O (oxo) distances (1.923 Å) and near linearity at the bridging oxygen (Sb–O–Sb 173.9°) are observed for 3.