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

Abstract

The dithia[3.3]paracyclophane-bridged bimetallic ruthenium alkynyl and vinyl complexes {Cp*(dppe)RuCC} 2 (μdithia[3.3]paracyclophane) (8) and {(PMe 3 ) 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.

Electronically Strongly Coupled Divinylheterocyclic‐Bridged Diruthenium Complexes

“…79–81 For the ruthenium alkenyl complexes that particular property rests on the high ability of the (CHCH)Ru(CO)Cl(P i Pr 3 ) 2 moiety to integrate into the π system of the parent alkyne RCCH, leading to unusually large alkenyl ligand contributions to the relevant “redox‐orbital(s)” in simple monoalkenyl ruthenium and ligand‐bridged bis(alkenyl) diruthenium complexes 17. 19, 20, 23, 28, 82–85…”

Bridge‐Localized HOMO‐Binding Character of Divinylanthracene‐Bridged Dinuclear Ruthenium Carbonyl Complexes: Spectroscopic, Spectroelectrochemical, and Computational Studies

“…After oxidation to 1 + – 4 + within a spectroelectrochemical cell, the ν (CO) bands of 1 + – 4 + show only a little change: the ν (CO) band of 3 + is most shifted to higher energy, but still merely by 1 cm −1 and broader. In addition, the IR spectrum of 1 + shows another weak absorption band at $\tilde \nu $ =1950 cm −1 , which most likely belongs to a secondary product 16b. When further electrolysis was performed in the OTTLE cell, the formation of 1 2+ , 2 2+ , and 4 2+ caused a decrease in peak intensity of the ν (CO) band near $\tilde \nu $ =1922 cm −1 , but displayed no frequency shift, whereas the ν (CO) band of complex 3 2+ sequentially shifted to higher energy at $\tilde \nu $ =1925 cm −1 ; this may contribute to the better coplanarity of carbonyl along with anthracene.…”

Experimental and Theoretical Studies of Charge Delocalization in Biruthenium–Alkynyl Complexes Bridged by Thiophenes

“…To further understand the electronic properties of structures [ 1a ] n + , [ 1b ] n + , and [ 1c ] n + , model complexes [ 1a H] n + , [ 1b H] n + , and [ 1c H] n + ( n =0, 1, 2) were selected and density functional theory (DFT) calculations were performed at the B3LYP/3‐21G* level of theory, as described in the literature 8b. i, 28 The extension “H” indicates that the η‐C 5 Me 5 and dppe ligands are replaced by η‐C 5 H 5 and two PH 3 ligands. Selected frontier orbitals of structures [ 1a H], [ 1b H], and [ 1c H] are shown in Figure 6 and the Supporting Information, Figure S5.…”