title: Metal-Metal Quadruple Bonds (M = Mo or W) Supported by 4-[2-(4-Pyridinyl)ethenyl] Benzoates and their Complexes with Tris(pentafluorophenyl)boron.
abstract: From the reactions between M2(T(i)PB)4 and two equivalents of the acids LH, the compounds trans-M2(T(i)PB)2L2 were isolated where M = Mo, compound I, and M = W, II, T(i)PB = 2,4,6-triisopropylbenzoate, and LH = 4-[2-(4-Pyridinyl)ethenyl]benzoic acid. In related reactions when tris(pentafluorophenyl)boron, A, was added, the Lewis acid-Lewis base complexes Mo2(T(i)PB)2(LA)2, IB, and W2(T(i)PB)2(LA)2, IIB, were isolated. Compounds I and IB are red and purple, respectively, while II and IIB are green. The new compounds have been characterized by (1)H NMR, UV-visible-NIR absorption spectroscopy, and electrochemical studies, which are tied together with density functional theory, DFT, and time-dependent DFT calculations. Chemical reduction of IB and IIB yields anions where the single electron occupies a ligand-based orbital as indicated by EPR spectroscopy. The LUMO and LUMO+1 are ligand-based, and are close in energy, and upon reduction, no IVCT is observed.
authors.affiliation: Department of Chemistry and Biochemistry, The Ohio State University , 100 West 18th Avenue, Columbus, Ohio 43210-1185, United States.
authors.forename: Malcolm H
authors.initials: MH
authors.lastname: Chisholm
authors.affiliation: Department of Chemistry and Biochemistry, The Ohio State University , 100 West 18th Avenue, Columbus, Ohio 43210-1185, United States.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Ziehm
mesh_terms: D001565:Benzoates / Q000138:chemical synthesis / Q000737:chemistry*; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D008024:Ligands; D008956:Models, Chemical; D015394:Molecular Structure; D008982:Molybdenum / Q000737:chemistry*; D010084:Oxidation-Reduction; D014414:Tungsten / Q000737:chemistry*
chemical_list: D001565:Benzoates; D056831:Coordination Complexes; D008024:Ligands; D008982:Molybdenum; D014414:Tungsten