Enhanced chain order and dependence of the linear absorption of poly (p-phenylenevinylene) on the solution environment of its precursor polymer

A large change in the linear absorption spectrum of poly (p-phenylenevinylene) (PPV) occurs when it is prepared from freshly synthesized and undialysed poly(sulfonium chloride) salt. The red shift of the linear absorption maximum of the PPV is 30–50 nm compared to that obtained from dialysed prepolymer. Subsequent changes in the chain order, as monitored by the changes in the linear absorption spectrum of the converted PPV, have been investigated as a function of solvent, time and temperature. The use of water in the polysulfonium ion synthesis is critical for the attainment of high chain order. Water was also found to be better than methanol in preserving the chemical and conformational integrity of the precursor salts. The observed effects of water have been attributed to its high ionizing and solvating ability, and a lower nucleophilicity compared to methanol.