Electrospray ionization mass spectrometry of non-covalent complexes formed between N -alkylimidazolium-containing zwitterionic sulfonates and protonated bases

摘要: This paper describes non-covalent complexes between zwitterionic 3-(1-alkyl-3N-imidazolio)- propane-1-sulfonates and different amines. Electrospray ionization (ESI) mass spectrometry collision- induced dissociation were used to measure the stability of such in solution gas phase. Generally, sulfonates formed more abundant with protonated 5-methylcytosine (5-MCH) than aliphatic The results show that association constants half-dissociation threshold energies these nonlinearly depend on alkyl chain length zwitterion. It is shown lowest exist acetonitrile or factors responsible for this complicated behavior are discussed. structure was investigated by quantum chemical calculations using molecular mechanics density functional theory. Hydrogen bonding proposed as main type interaction ion-zwitterion complexes. In summary, information obtained study could be development new derivatization reagents some compounds containing amidinium groups, like 5-MCH, increase selectivity ESI-based methods.