P. Genix et al., ESTIMATION OF HAMMETT SIGM-CONSTANTS FROM CALCULATED ATOMIC CHARGES USING PARTIAL LEAST-SQUARES REGRESSION, Journal of chemometrics, 10(5-6), 1996, pp. 631-636
Hammett constants describe the electronic donating or withdrawing capa
bilities of a given substituent. Since Hammett constants represent inf
ormation of an electronic nature, their values are to be linked with a
tomic charges and orbital-derived parameters of the atoms of the subst
rate bearing the substituent. A series of 132 para- and meta-substitut
ed benzoic acid structures has been built and energy minimized using M
OPAC/AM1. Atomic charges and frontier orbital coefficients of the benz
oic moiety have been calculated. These parameters were highly interrel
ated. Using partial least squares regression, we showed that Hammett c
onstants can be satisfactorily estimated from these electronic paramet
ers. (C) 1996 by John Wiley & Sons, Ltd.