Synthesis and structures of new mono- and multi-nuclear benzyltin carboxylates and phosphinates: A novel dibenzyltin phosphinate stabilized by intramolecular hydrogen bonding

Abstract

The reaction of dibenzyltin dichloride 1 with 2 mol equivalents each of AgO2P(C6H11)2 and (C6H11)2PO2H afforded the novel monometallic complex Sn(CH2Ph)2[O2P(C6H 11)2]2[HO2P(C6H 11)2]2 2. When 1 was treated with 2 mol equivalents of AgO2P(C6H11)2 only the trinuclear O-capped cluster [{Sn(CH2Ph)(OH)[O2P(C6H11) 2]}3O]-[O2P(C6H11) 2] 4 was obtained by an Sn-C bond cleavage via an intermediate formulated as {Sn(CH2Ph)(OH)-[O2P(C6H11) 2]2}2 3. In the reaction with silver carboxylates the type of product isolated depends on the carboxylic acid used. Thus the 'ladder' {[(PhCH2)SnO·O2CMe]2(PhCH 2)Sn(O2CMe)3}2 5, the 'hexagonal prismanes' [(PhCH2)SnO·O2CR]6 (R = Me 6, But 7, C5H4N 8, CH=CMe2 9 or CHPh2 10) and the mononuclear compound Sn(CH2Ph)2(O2CCHPh2)2 11 have been isolated. X-Ray structural analysis confirmed the identities of 2, 4·CHCl3, and 5·2CH2Cl2. In 2 the mononuclear structure is stabilized by internal hydrogen bonding between P-OH and P=O of the co-ordinated phosphinic acid and the phosphinate, respectively, from the same molecule. Compound 4 has a tristannoxane ring with a capping oxygen, whereas in 5 the stannoxane skeleton is that of a 'ladder' with three different types of tin.