Dithiocarbamate anchoring in molecular wire junctions: A first principles study
Dithiocarbamate anchoring in molecular wire junctions: A first principles study
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DOI：
10.1021/jp0610665
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发表时间：
2006-05-25
影响因子：
3.3
通讯作者：
Kosov, Daniel S.
中科院分区：
文献类型：
--
作者：
Li, Zhenyu;Kosov, Daniel S.
最近的实验实现[J。化学会，127（2005）7328]中描述的方法，为使用二硫代氨基甲酸酯接头将分子线锚定到金电极上提供了可能性。在本文中，我们探讨这个假设计算。基于密度泛函理论和非平衡绿色函数，计算了4，4 '-联吡啶（BP），4，4'-联吡啶-1，1 '-二硫代酸盐（BPBC），4-（4'-吡啶基）-二硫代酸盐（BPC）分子结的电子输运性质.我们证明了与共轭二硫代氨基甲酸酯连接体相关的较强的分子-电极耦合加宽了费米能附近的透射共振。随着π共轭从分子到金电极的扩展，加宽效应沿着产生，导致BPBC分子电导增强。在外加偏压为1.0 V时，电导增强因子高达25。预测了具有不对称锚定基团的BPC分子线结的整流行为。
Recent experimental realization [J. Am. Chem. Soc., 127 ( 2005) 7328] of various dithiocarbamate self-assembly on gold surface opens the possibility for use of dithiocarbamate linkers to anchor molecular wires to gold electrodes. In this paper, we explore this hypothesis computationally. We computed the electron transport properties of 4,4'-bipyridine (BP), 4,4'-bipyridinium-1,1'-bis(carbodithioate) (BPBC), 4-(4'-pyridyl)-peridium-1- carbodithioate (BPC) molecule junctions based on the density functional theory and nonequilibrium Green's functions. We demonstrated that the stronger molecule-electrode coupling associated with the conjugated dithiocarbamate linker broadens transmission resonances near the Fermi energy. The broadening effect along with the extension of the pi conjugation from the molecule to the gold electrodes lead to enhanced electrical conductance for BPBC molecule. The conductance enhancement factor is as large as 25 at applied voltage bias 1.0 V. Rectification behavior is predicted for BPC molecular wire junction, which has the asymmetric anchoring groups.