Electrospray mass spectrometric studies on the solution chemistry of triorganostannyl trifluoromethanesulfonates

Compounds of the type R3Sn(OSO2CF3) (triorganostannyl trifluoromethanesulfonates, R = Me, Bu, Ph) were synthesized and investigated in solution using electrospray mass spectrometry. The mono-acetonitrile adduct [R3Sn .(CH3CN)](+) is the dominant ionic species in acetonitrile solution, with a weaker signal owing to R3Sn+ The relative intensity of R3Sn+ increases significantly upon the use of dichloromethane as a solvent. Variable temperature Sn-119 NMR studies were also undertaken on the trimethylstannyl and triphenylstannyl trifluoromethanesulfonates in dichloromethane solution. The Sn-119 chemical shifts and Lewis-base adduction studies; reveal that the triorganostannyl trifluoromethanesulfonates are only slightly more Lewis-acidic than the corresponding triorganostannyl chlorides. These solutions are too labile to be studied on the NMR timescale.