Activation of E–Cl bonds (E = C, Si, Ge and Sn) by a C,N-chelated stannylene

Abstract

The reactivity of (L(CN))(2)Sn (1) (where L(CN) is 2-(N,N-dimethylaminomethyl)phenyl-) towards various substrates containing E–Cl bond(s) has been studied (E = C, Si, Ge and Sn). Alkyl chlorides like chloroform or dichloromethane reacts with 1 to form (L(CN))(2)SnCl(2) and unidentified by-products in poor yields. The reaction of benzoyl chloride with 1 at low temperature yielded a thermally unstable product (L(CN))(2)Sn(Cl)C(O)Ph (2) which was isolated and characterized by both multinuclear NMR spectroscopy and X-ray diffraction techniques. The vicinity of the central tin atom in 2 reveals trigonal bipyramidal geometry. Attempts to oxidize 2 by dioxygen to give the corresponding organotin(IV) benzoate failed. On the other hand, the reaction of the in situ prepared (L(CN))(2)Sn=O (synthesized by the reaction of 1 with dioxygen) with PhCOCl resulted in the formation of the desired organotin(IV) benzoate (L(CN))(2)Sn(Cl)C(=O)OPh (3). The reaction of 1 with Ph3GeCl yielded triphenylgermyl-substituted diorganotin(IV) chloride (L(CN))(2)Sn(Cl)GePh(3) (4) which subsequently gave mixed diorganotin(IV) chloride-oxide [(L(CN))(2)SnCl](2)O (5) upon loss of the GePh(3) moiety in the air. When the same reaction was carried out in benzene instead of chloroform a unique [Ph(3)Ge](4)[Sn(6)O(8)] cluster (6) was obtained. Similarly, the reaction of 1 with Ph3SiCl provided triphenylsilyl-substituted diorganotin(IV) chloride (L(CN))(2)Sn(Cl)SiPh(3) (7) which was then oxidized to (L(CN))(2)Sn(Cl)OSiPh(3) (8). The unprecedented reaction of 1 with (n-Bu)(3)SnCl provided the distannane (L(CN))(2)Sn(Cl)SnBu(3) (9) which could be oxidized by dioxygen to a distannoxane (L(CN))(2)Sn(Cl)OSnBu(3) (10). In addition, the solid-state structures of 3, 5, 6 and 8 were determined by the X-ray diffraction techniques.