The thiolate anion as a nucleophile Part XI. Effect of the size of the nucleophile

The nucleophilic substitution reactions of some simple fluorobenzenes, C₆H_6?xF_x with sodium methanethiolates Na⁺SR^?(R=Et, $\text{i}$-Pr, $\text{t}$-Bu) have been studied. Some fully substituted products, C₆H_6?x(SR)_x, could be obtained in DMF as solvent with R = Et and $\text{i}$-Pr, but not when R = $\text{t}$-Bu. All the new products isolated have been characterized by elemental analysis, and NMR (H-1 and F-19), infrared and mass spectroscopy.