Termination and side-reactions of polystyryllithium with beta-bromostyrene.

Low molecular weight polystyryllithium was synthesised and terminated with a two-fold molar excess of beta-bromostyrene to produce an end-functionalised polymer. 1,3-Diphenylallyl-terminated polystyrene and other reaction products were analysed by FT-Raman spectroscopy. By comparison with model compounds, it can be deduced that beta-bromostyrene with a predominantly trans configuration gave rise to primarily cis conformational unsaturation at the polystyrene chain-end. It was also demonstrated that a polystyrene 'dimer' and 1,4-diphenylbutadiene were produced via side-reactions which are considered to result from metal-halogen exchange in the reagents.