the challenge of synthesizing oligomers for molecular wires合成的寡聚物分子导线的挑战.pdf

Polymers 2011, 3, 545-557; doi:10.3390/polym3010545 OPEN ACCESS polymers ISSN 2073-4360 /journal/polymers Article The Challenge of Synthesizing Oligomers for Molecular Wires Roar Søndergaard and Frederik C. Krebs * RisøNational Laboratory for Sustainable Energy, Technical University of Denmark, Frederiksborgvej 399, DK-4000 Roskilde, Denmark; E-Mail: rosq@risoe.dtu.dk * Author to whom correspondence should be addressed; E-Mail: frkr@risoe.dtu.dk; Tel.: +45-4677-4799; Fax: +45-4677-4791. Received: 17 January 2011; in revisedform: 6 February 2011 / Accepted: 23 February 2011 / Published: 28 February 2011 Abstract: Controlling the size of the oligomer and introducing functional groups at the ends of the oligomer that allow it to react with separate electrodes are critical issues when preparing materials for molecular wires. We demonstrate a general synthetic approach to oligophenylenevinylene (OPV) derivative molecules with a molecular length up to 9–10 nm which allow for the introduction of aromatic thioacetate functionality in fully conjugated oligomer systems. Oligomers containing 3–15 phenyl units were synthesized by step wise Horner-Wadsworth-Emmons (HWE) reactions of a bifunctional OPV-monomer, which demonstrated good control of the size of the OPVs. Workup after each reaction step ensures a high purity of the final products. End group functionalization was introduced as a last step. Keywords: molecular wire; oligomer; oligophenylenevinylene; aromatic thioacetate