Fluorescence quenching of para‐substituted styrenes by tetramethylethylene. Correlation analysis of the quenching coefficient KSV and the quenching rate constant kq by the dual‐parameter equation with polar and spin‐delocalization substituent constants

Abstract The fluorescence quenching coefficient ( K SV ) and the quenching rate constant k q of ten para ‐substituted styrenes (1‐Ys) have been measured and correlation‐analyzed by both the dual‐parameter equation (Eq. 1) with (ρ x σ x + ρ · σ · ) and the single‐parameter equation (Eq. 2) with ρ x σ x . Excellent results have been obtained for the correlation of K SV against (ρ x σ mb + ρ · σ · JJ ) or (ρ x σ + + ρ · σ · JJ ). Our results suggest that, possibly, there might be no need to use excited‐state substituent constant for the fluorescence quenching process of excited states of styrenes.