A modified Wittig polycondensation––to high-trans- and high-molecular weight PPVs

A modified Wittig polycondensation was developed by replacing the bulky −PPh3 with −PBu3 ylide. Our studies suggested that the modified polymerization dramatically enhances trans-selectivity due to the decreased 1,3-steric interaction between butyl chain and triphenylamine group, together with the 1,2-steric interaction between the phenyl ring of the ylide and the triphenylamine group of the aldehyde. Moreover, the method also enhances high-molecular weight products by increasing the activity and solubility of the ylide.