Bellec Nathalie, Vacher Antoine, Barrière Frédéric, Xu Zijun, Roisnel Thierry, Lorcy Dominique
Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, Campus de Beaulieu, Bât 10A, 35042 Rennes cedex, France.
Inorg Chem. 2015 May 18;54(10):5013-20. doi: 10.1021/acs.inorgchem.5b00632. Epub 2015 Apr 30.
Tetrathiafulvalenes (TTF) and bis(cyclopentadienyl) molybdenum dithiolene complexes, Cp2Mo(dithiolene) complexes, are known separately to act as good electron donor molecules. For an investigation of the interaction between both electrophores, two types of complexes were synthesized and characterized. The first type has one Cp2Mo fragment coordinated to one TTF dithiolate ligand, and the second type has one TTF bis(dithiolate) bridging two Cp2Mo fragments. Comparisons of the electrochemical properties of these complexes with those of models of each separate electrophore provide evidence for their mutual influence. All of these complexes act as very good electron donors with a first oxidation potential 430 mV lower than the tetrakis(methylthio)TTF. DFT calculations suggest that the HOMO of the neutral complex and the SOMO of the cation are delocalized across the whole TTF dithiolate ligand. The X-ray crystal structure analyses of the neutral and the mono-oxidized Cp2Mo(dithiolene)(bismethylthio)TTF complexes are consistent with the delocalized assignment of the highest occupied frontier molecular orbitals. UV-vis-NIR spectroelectrochemical investigations confirm this electronic delocalization within the TTF dithiolate ligand.
四硫富瓦烯（TTF）和双（环戊二烯基）钼二硫纶配合物，即Cp2Mo（二硫纶）配合物，分别被认为是良好的电子供体分子。为了研究这两种电子受体之间的相互作用，合成并表征了两种类型的配合物。第一种类型是一个Cp2Mo片段与一个TTF二硫纶配体配位，第二种类型是一个TTF双（二硫纶）桥连两个Cp2Mo片段。将这些配合物的电化学性质与每个单独电子受体的模型进行比较，为它们的相互影响提供了证据。所有这些配合物都是非常好的电子供体，其第一氧化电位比四（甲硫基）TTF低430 mV。密度泛函理论计算表明，中性配合物的最高占据分子轨道（HOMO）和阳离子的单占据分子轨道（SOMO）在整个TTF二硫纶配体上离域。中性和单氧化的Cp2Mo（二硫纶）（双甲硫基）TTF配合物的X射线晶体结构分析与最高占据前沿分子轨道的离域归属一致。紫外-可见-近红外光谱电化学研究证实了TTF二硫纶配体内的这种电子离域。
