Synthesis, Characterization, and Properties of Anthracene-Bridged Bimetallic Ruthenium Vinyl Complexes [RuCl(CO)(PMe₃)₃]₂(μ-CH═CH-anthracene-CH═CH)

Abstract

Four anthracene-based bimetallic ruthenium vinyl complexes, in which two ruthenium units are attached at different positions (the 9,10-, 1,5-, 2,6-, and 1,8-positions) of the anthracene moiety, have been synthesized by treating the appropriate anthracene-based ethynes with [RuHCl(CO)(PPh3)3]. These bimetallic complexes have been thoroughly characterized by NMR, X-ray diffraction, and elemental analysis. According to the single-crystal X-ray structures, the 2,6-disubstituted ruthenium vinyl complex has a more planar structure compared with the 9,10-disubstituted complex, possibly because it has less steric hindrance. Furthermore, we have investigated the optical electronic properties of these complexes, such as their UV/vis absorption spectra, fluorescence spectra, and electrochemical properties. The optical electronic results indicated that the 2,6-disubstituted ruthenium vinyl complex displayed the strongest fluorescence emission due to the more planar structure of its organic conjugated bridge, and the electrochemical studies showed that the two ruthenium centers displayed obvious differences in electronic communication when they are located at different positions on the anthracene unit, with the 9,10- and 1,8-disubstituted ruthenium vinyl complexes exhibiting better electronic communication and higher stability of the mixed-valence complex than the 1,5- and 2,6-disubstituted complexes.

Electronic Structures of Divinylchalcogenophene‐Bridged Biruthenium Complexes: Exploring Trends from O to Te

“…Binuclear ruthenium mixed‐valence complexes incorporating two “RuCl(CO)(PR 3 ) 2 L” (L = neutral two‐electron donor or free coordination site) redox‐active termini connected by a carbon‐rich unsaturated spacer display well‐behaved redox chemistry and are ideally suited for studies of the electron‐density distribution and interplay between the properties of the bridge and metal centres as well as charge‐transfer characteristics , , , , , . In particular, the synergistic nature of the bonding interactions between the Ru metal centre and ancillary CO ligand results in the v (CO) IR band being an excellent reporter group of metal electron density , , .…”

Electronically Strongly Coupled Divinylheterocyclic‐Bridged Diruthenium Complexes

“…[16] More recently it was found that such ruthenium alkenyl complexes display aw ell-behaved redox chemistry and are thus particularly suited for the investigation of intramolecular electron-transfer processesi no rganometallic compounds comprising two or more of such redox-actives ites. [17][18][19][20][21][22][23][24][25][26][27][28][29] In addition to their relatively low oxidation potentials, their associated radical cations are quite stable and can thus be investigatedb ye lectronic, vibrational and EPR spectroscopy.…”

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

“…[19] Because of interesting electronic properties associated with the delocalized linear p system, anthracene and its derivatives have also been used as bridging ligands to build up mixed-valence di-and polynuclear metal complexes. [20] In a previous report, we described the syntheses of a series of divinylanthracenebridged diruthenium carbonyl complexes 1-4.…”