Substituent group effects on the NQR frequency of Cl in certain chloromethane derivatives

Abstract

AbstractAn empirical method is suggested for estimating the NQR frequencies of substituted chloromethanes. The frequencies are given by the equation νCl = νo + ∑imi, where the parameters mi are characteristic of the substituent groups, with additive properties in the case of multiple substitution for substituted chloromethanes. The calculations reveal that (i) as in chlorobenzenes, the effect of substituent groups on the NQR frequencies is additive to a first order of approximation, (ii)the effect is much larger in chloromethanes than in chlorobenzenes, (iii) the relative effects of different substituent groups are similar in the two sets, (iv) where there is more than one substituent group their mutual interaction is of the same order of magnitude as the crystal field effects.