Quantum interference and heteroaromaticity of para- and meta-linked bridged biphenyl units in single molecular conductance measurements.

ABSTRACT: Is there a correlation between the (hetero)aromaticity of the core of a molecule and its conductance in a single molecular junction? To address this question, which is of fundamental interest in molecular electronics, oligo(arylene-ethynylene) (OAE) molecular wires have been synthesized with core units comprising dibenzothiophene, carbazole, dibenzofuran and fluorene. The biphenyl core has been studied for comparison. Two isomeric series have been obtained with 4-ethynylpyridine units linked to the core either at para-para positions (para series 1-5) or meta-meta positions (meta series 6-10). A combined experimental and computational study, using mechanically controlled break junction measurements and density functional theory calculations, demonstrates consistently higher conductance in the para series compared to the meta series: this is in agreement with increased conjugation of the ?-system in the para series. Within the para series conductance increases in the order of decreasing heteroaromaticity (dibenzothiophene?

SUBMITTER: Gantenbein M 

PROVIDER: S-EPMC5431762 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature