Precise Synthesis of End-Functionalized Oligo(2,5-dialkoxy-1,4-phenylene vinylene)s with Controlled Repeat Units via Combined Olefin Metathesis and Wittig-Type Coupling

The precise synthesis of chemically, analytically pure oligo(2,5-dialkoxy-1,4-phenylene vinylene)s [OPVs, alkoxy = O(CH2)(2)OSiiPr(3)] with strictly controlled repeat units (up to 15 repeat units) and well-defined end groups has been achieved by a combined olefin metathesis reaction of 2,5-dialkon-1,4 divinylbenzene or their derivatives with a molybdenum-alkylidene complex and the subsequent Wittig-type cleavage with their dicarboxaldehyde analogues. The effects of the repeat units and the end functional groups toward their UV-vis and the fluorescence spectra have been clearly demonstrated.