Effect of Metal−Metal Interactions on Electron Transfer: an STM Study of One-Dimensional Metal String Complexes

Linear metal string complexes of [MnL4(NCS)2] (Scheme , M = NiII, CoII, or CrII; n = 3 or 5; L = dpa- or
tpda2- where dpa- is dipyridylamido anion and tpda2- is tripyridyldiamido dianion) are studied for the
fundamental understanding of the effect of inter-nuclei interactions on electron transfer (ET). The metal strings
are isolated within n-alkanethiol monolayers and the properties of ET through various metal strings are
differentiated by scanning tunneling microscopy. Although very similar in physical dimension, their apparent
heights against the same alkanethiol background are significantly different. The discrepancy is ascribed to
electron localization−delocalization among the metal centers.

本研究以[MnL4(NCS)2]型线性金属链配合物（Scheme，其中M为NiII、CoII或CrII；n=3或5；配体L为dpa-或tpda2-，dpa-为二吡啶胺阴离子，tpda2-为三吡啶二胺二阴离子）为研究对象，旨在从基础层面阐明核间相互作用对电子转移（ET）的影响。将此类金属链隔离于正烷硫醇单分子膜中，借助扫描隧道显微镜（STM）区分不同金属链介导的电子转移特性。尽管这些金属链的物理尺寸极为相近，但在相同的烷硫醇背景下，它们的表观高度却存在显著差异。这种表观高度的差异可归因于金属中心之间的电子定域-离域效应。