FLUORESCENCE QUENCHING OF PARASUBSTITUTED STYRENES BY TETRAMETHYLETHYLENE - CORRELATION-ANALYSIS OF THE QUENCHING COEFFICIENT K-SV AND THE QUENCHING RATE-CONSTANT K(Q) BY THE DUAL-PARAMETER EQUATION WITH POLARAND SPIN-DELOCALIZATION SUBSTITUENT CONSTANTS

The fluorescence quenching coefficient (K-SV) and the quenching rate c onstant kg of ten para-substituted styrenes (1-Ys) have been measured and correlation-analyzed by both the dual-parameter equation (Eq. 1) w ith (rho(x) sigma(x)+rho(.)sigma(.)) and the single-parameter equation (Eq. 2) with rho(x) sigma(x). Excellent results have been obtained fo r the correlation of K-SV against (rho(x) sigma(mb) + rho(.)sigma(JJ)( .)) or (rho(x) sigma(+)+rho(.)sigma(JJ)(.)). Our results suggest that, possibly, there might be no need to use excited-state substituent con stant for the fluorecence quenching process of excited states of styre nes.