Substituent effect on the UV spectra of p‐disubstituted compounds XPh(CHCHPh) n Y ( n = 0, 1, 2)

Three parameters, ${\rm \sigma }_{\rm CC}^{\rm ex} $ , ${\rm \sigma }_{\rm CC}^{\rm ex} ({\rm XY)}$ and $\upsilon_{{\rm max,}\,{\rm parent}} $ , are developed to express the substituent effect and the effect of the parent molecular structure of p‐disubstituted compounds XPh(CHCHPh) n Y ( n  = 0, 1, 2). The investigated result shows a good correlation between the UV absorption wavenumbers ( υ max ) and the three parameters for a diverse set of title compounds, and the correlation equation can be used to predict the UV absorption energy of compounds with the mentioned structure. This approach provides a new insight for the quantitative structure‐property relationship (QSPR) correlation of the UV absorption energy of p‐disubstituted homologues. Copyright © 2010 John Wiley & Sons, Ltd.