Nuclear Quadrupole Resonance Study of β-Chloroisocrotonic Acid

Abstract

Abstract 35Cl nuclear quadrupole resonance frequencies have been measured in powders of β-chlorocrotonic acid, and β-chloroisocrotonic acid to be 34.966 and 34.261 MHz, respectively, at 78 K. Zeeman effect experiments were conducted on a single crystal of β-chloroisocrotonic acid and the asymmetry parameter of the electric field gradient has been determined to be 0.174±0.016 at 78 K. The π-electron density on the chlorine site has been estimated from the asymmetry parameter according to Bersohn and discussed on the basis of the semi-empirical Pariser-Parr-Pople molecular orbital treatment.