Acidity of Cl3SnCH2CH2CO2H

Abstract Interaction of Cl 3 SnCH 2 CH 2 CO 2 H with aniline bases in CH 2 Cl 2 solution has been studied by UV-visible spectroscopy. As measured by the extents of complexation with the bases, Cl 3 SnCH 2 CH 2 CO 2 H is a stronger acid than the corresponding esters, Cl 3 SnCH 2 CH 2 CO 2 R (Lewis acids) and also very much more stronger than the Bronsted acid, CH 3 CH 2 CO 2 H. The enhanced Bronsted acidity arises from the stabilisation of the anion, Cl 3 SnCH 2 CH 2 CO 2 − , by the intramolecular coordination of the tin centre by the carboxylate group.