Excited state lifetimes were determined from fluorescence decays measured in time-resolved studies. These lifetimes are inversely proportional to the excited state decay rate constants in the absence (k0) and presence (kobs) of quencher. The quenching rate constant was obtained from the linear relationship between kobs for each emitting species and the quencher concentration (eq 3). Changes in the normalized absorption and emission spectra of OTPh (0.02 mg mL -1 ) showed that all OTPh was solubilized at 50 mM NaDC and higher concentrations (Figure ), since the absorption maxima and peak ratios between the absorbance at 300-310 nm and 250-260 nm of OTPh were similar to those in chloroform where OTPh is completely soluble. In contrast at 25 mM NaDC, the OTPh absorption peak ratio was lower than observed in chloroform suggesting only partial solubilization of the oligomer. The molar absorption coefficients at the absorption maxima of 301 and 305 nm for OTPh in 50 and 100 mM NaDC were determined to be 18.8 ± 0.5 mL mg - cm -1 and 21.0 ± 0.2 mL mg -1 cm -1 , respectively (Figure , average of two independent experiments), suggesting that OTPh is in similar environments at these two NaDC concentrations.