title: Effects of hydrogen bonding on current-voltage characteristics of molecular junctions.
abstract: We present a first-principles study of hydrogen bonding effect on current-voltage characteristics of molecular junctions. Three model charge-transfer molecules, 2'-amino-4,4'-di(ethynylphenyl)-1-benzenethiolate (DEPBT-D), 4,4'-di(ethynylphenyl)-2'-nitro-1-benzenethiolate (DEPBT-A), and 2'-amino-4,4'-di(ethynylphenyl)-5'-nitro-1-benzenethiolate (DEPBT-DA), have been examined and compared with the corresponding hydrogen bonded complexes formed with different water molecules. Large differences in current-voltage characteristics are observed for DEPBT-D and DEPBT-A molecules with or without hydrogen bonded waters, while relatively small differences are found for DEPBT-DA. It is predicted that the presence of water clusters can drastically reduce the conductivities of the charge-transfer molecules. The underlying microscopic mechanism has been discussed.
authors.affiliation: Theoretical Chemistry, Royal Institute of Technology, AlbaNova, S-106 91 Stockholm, Sweden.
authors.forename: Mathias
authors.initials: M
authors.lastname: Kula
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
authors.forename: Yi
authors.initials: Y
authors.lastname: Luo