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.