Studies of the complexes of the 4-cyanophenyl[bis(ethylsulfonyl)]methane and 4-cyanophenyl[bis(benzylsulfonyl)]methane C-acids and TBD and MTBD N-bases

The 1:1 complexes of 4-cyanophenyl[bis(ethylsulfonyl)]methane (CHA) and 4-cyanophenyl[bis(benzylsulfonyl)]methane (CHB) with 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) have been examined by ESI MS, 1H NMR and FT-IR spectroscopy. In all complexes, the proton transfer from the CH acid to the N-base was observed with the formation of the ionic pairs. The presence of carbanions within the complexes was directly detected in the negative ion mode ESI MS spectra. The fragmentation pathways of the carbanions of CHA and CHB are proposed.