title: π-Bonded dithiolene complexes: synthesis, molecular structures, electrochemical behavior, and density functional theory calculations.
abstract: The synthesis and X-ray molecular structure of the first metal-stabilized o-dithiobenzoquinone [Cp*Ir-o-(η(4)-C(6)H(4)S(2))] (2) are described. The presence of the metal stabilizes this elusive intermediate by π coordination and increases the nucleophilic character of the sulfur atoms. Indeed, the π-bonded dithiolene complex 2 was found to react with the organometallic solvated species [Cp*M(acetone)(3)][OTf](2) (M = Rh, Ir) to give a unique class of binuclear dithiolene compounds [Cp*Ir(C(6)H(4)S(2))MCp*][OTf](2) [M = Rh (3), Ir (4)] in which the elusive dithiolene η-C(6)H(4)S(2) acts as a bridging ligand toward the two Cp*M moieties. The electrochemical behavior of all complexes was investigated and provided us with valuable information about their redox properties. Density functional theory (DFT) calculations on the π-bonded dithiobenzoquinone ligand and related bimetallic systems show that the presence of Cp*M at the arene system of the dithiolene ligand increases the stability compared to the known monomeric species [Cp*Ir-o-(C(6)H(4)S(2)-κ(2)-S,S)] and enables these complexes Cp*Ir(C(6)H(4)S(2))MCp*][OTf](2) (3 and 4) to act as electron reservoirs. Time-dependent DFT calculations also predict the qualitative trends in the experimental UV-vis spectra and indicate that the strongest transitions arise from ligand-metal charge transfer involving primarily the HOMO-1 and LUMO. All of these compounds were fully characterized and identified by single-crystal X-ray crystallography. These results illustrate the first examples describing the coordination chemistry of the elusive o-dithiobenzoquinone to yield bimetallic complexes with an o-benzodithiolene ligand. These compounds might have important applications in the area of molecular materials.
authors: UPMC Université Paris 06, Institut Parisien de Chimie Moléculaire (UMR CNRS 7201), 4 place Jussieu, C. 42, 75252 Paris Cedex 05, France.
authors: Aurélie
authors: A
authors: Damas
authors: Lise-Marie
authors: LM
authors: Chamoreau
authors: Andrew L
authors: AL
authors: Cooksy
authors: Anny
authors: A
authors: Jutand
authors: Hani
authors: H
authors: Amouri
mesh_terms: D018360:Crystallography, X-Ray; D055664:Electrochemical Techniques; D007495:Iridium / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D011789:Quantum Theory; D012428:Ruthenium / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D013438:Sulfhydryl Compounds; D007495:Iridium; D012428:Ruthenium