The synthesis and 19F NMR spectra of some derivatives of (4-fluorophenyl)dimethyltin

Abstract

A number of (4-fluorophenyl)dimethyltin compounds and their carbon analogues have been prepared, and the fluorine chemical shifts for these compounds relative to fluorobenzene as an internal standard have been determined in cyclohexane, chloroform and pyridine. It has been shown that the electron-accepting capacity of the Sn-(CH 3) 2X substituents (where X is a heteroatom) increases in chloroform solution and decreases in pyridine solution relative to the value in cyclohexane, pyridine inhibiting transmission of electronic effects through the tin atom. Correlation between the 19F chemical shifts and the σ 1 and Σσ 0 values for the groups on the metal atom has been found, indicating that the electronic interactions between the substituents and the tin atom are mainly inductive in nature. The abilities of Sn(CH 3) 2 and C(CH 3) 2 bridging groups to transmit such electronic effects have been shown to be similar.