Synthesis and Characterization of Dithia[3.3]paracyclophane-Bridged Binuclear Ruthenium Vinyl and Alkynyl Complexes

The dithia[3.3]­paracyclophane-bridged bimetallic ruthenium alkynyl and vinyl complexes {Cp*­(dppe)­RuCC}2(μ-dithia­[3.3]­paracyclophane) (8) and {(PMe3)3(CO)­ClRuCHCH}2(μ-dithia­[3.3]­paracyclophane) (9) have been prepared and, in the case of 8, structurally characterized. Compounds 8 and 9 each undergo two consecutive one-electron-oxidation processes, with supporting investigations conducted using IR and UV/vis/near-IR spectroelectrochemical methods establishing the redox-noninnocent character of the dithia[3.3]­paracyclophane bridge unit in both 8 and 9. Both [8]+ and [9]+ exhibit multiple transitions in the near-IR region, which have been assigned with the aid of DFT calculations to combinations of MLCT and intraligand transitions and transitions involving the donor sulfur atoms within the cyclophane scaffold to the partially occupied orbital located on the diethynyl- or divinylphenylene portion of the bridging cyclophane.

本研究合成了以二硫杂[3.3]对环芳烷（dithia[3.3]paracyclophane）为桥联单元的双金属钌炔基与乙烯基配合物：{五甲基环戊二烯基(1,2-双(二苯基膦基)乙烷, dppe)钌乙炔基}₂(μ-二硫杂[3.3]对环芳烷)(8)与{(三甲基膦)₃(羰基)氯化钌乙烯基}₂(μ-二硫杂[3.3]对环芳烷)(9)；其中配合物8的晶体结构已得到解析。配合物8与9均可经历两步连续的单电子氧化过程，借助红外（IR）、紫外-可见-近红外光谱电化学方法开展的辅助研究证实，二硫杂[3.3]对环芳烷桥联单元在两种配合物中均表现出氧化还原非惰性特征。阳离子物种[8]+与[9]+的近红外区域均存在多个电荷转移跃迁，结合密度泛函理论（DFT, Density Functional Theory）计算结果，可将这些跃迁归属为金属到配体电荷转移（MLCT, Metal-to-Ligand Charge Transfer）、配体内电荷转移跃迁，以及环芳烷骨架内供体硫原子向桥联环芳烷中二乙炔基或二乙烯基苯亚苯基部分的部分占据轨道的电荷转移跃迁的组合。