Organosilicon–organotin indenyl derivatives. A nuclear magnetic resonance study of their fluxional characteristics

Abstract

The fluxional molecules bis(trimethylsilyl)(trimethylstannyl)indene, (trimethylyl)(trimethylstannyl)indene and bis(trimethylstannyl)indene have been studied by ¹H n.m.r. spectroscopy over the temperature range 0–170°C. The Arrhenius parameters for the metallotropic shift of the trimethylstannyl groups have been determined. Although, in the case of bis(trimethylstannyl)indene, the abundances of the two fluxional isomers were grossly dissimilar (ratio > 20/1), the very sensitive temperature dependence of the spectra enabled accurate rate parameters to be deduced. The spectral line shape changes in all cases were found to be completely compatible with 1,3-metallotropic shifts of the trimethylstannyl group.