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Silver Makes Better Electrical Contacts to Thiol‐Terminated Silanes than Gold
Author(s) -
Li Haixing,
Su Timothy A.,
CamarasaGómez María,
HernangómezPérez Daniel,
Henn Simon E.,
Pokorný Vladislav,
Caniglia Caravaggio D.,
Inkpen Michael S.,
Korytár Richard,
Steigerwald Michael L.,
Nuckolls Colin,
Evers Ferdinand,
Venkataraman Latha
Publication year - 2017
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201708524
Subject(s) - silanes , conductance , covalent bond , silane , thiol , molecule , electrode , metal , density functional theory , materials science , work function , nanotechnology , chemistry , chemical physics , computational chemistry , organic chemistry , composite material , condensed matter physics , metallurgy , physics
We report that the single‐molecule junction conductance of thiol‐terminated silanes with Ag electrodes are higher than the conductance of those formed with Au electrodes. These results are in contrast to the trends in the metal work function Φ(Ag)<Φ(Au). As such, a better alignment of the Au Fermi level to the molecular orbital of silane that mediates charge transport would be expected. This conductance trend is reversed when we replace the thiols with amines, highlighting the impact of metal–S covalent and metal–NH 2 dative bonds in controlling the molecular conductance. Density functional theory calculations elucidate the crucial role of the chemical linkers in determining the level alignment when molecules are attached to different metal contacts. We also demonstrate that conductance of thiol‐terminated silanes with Pt electrodes is lower than the ones formed with Au and Ag electrodes, again in contrast to the trends in the metal work‐functions.