title: MM Quadruply Bonded Complexes Supported by Vinylbenzoate Ligands: Synthesis, Characterization, Photophysical Properties and Application as Synthons.
abstract: From the reactions between M2(TiPB)4compounds andmetaandpara- vinylbenzoic acids (2 equiv) in toluene at room temperature the compoundstrans-M2(TiPB)2L2, where L =m-vinylbenzoate1A(M = Mo) and1B(M = W) and TiPB = 2,4,6-triisopropylbenzoate, and where L =p-vinylbenzoate2A(M = Mo) and2B(M = W) have been isolated. Compounds1Aand2Ahave been shown to undergo Heck carbon-carbon coupling reactions with phenyliodide to producetrans-Mo2(TiPB)2(O2CC6H4-m-CH=CH-C6H5)2,3Aandtrans-Mo2(TiPB)2(O2CC6H4-p-CH=CH-C6H5)2,4A. The molybdenum compounds1Aand2Ahave been structurally characterized by single crystal X-ray crystallography. All the new compounds have been characterized by1H NMR, IR, UV-Visible absorption and emission spectroscopy, high resolution MALDITOF MS, fs- and ns- transient absorption spectroscopy and fs- time-resolved IR spectroscopy. Electronic structure calculations employing density functional theory, DFT, and time-dependent DFT have been employed to aid in the interpretation of spectral data. All compounds show intense absorptions in the visible region corresponding to M2δ to Lπ* charge transfer transitions. The lifetimes of the1MLCT state fall in the range of 1 - 10 ps and for the molybdenum complexes the T1states are3δδ* with lifetimes ~50 μs while for the tungsten complexes the T1are3MLCT with lifetimes in the range of 3 - 10 ns.
authors.affiliation: The Ohio State University, Department of Chemistry and Biochemistry, 100 W. 18 Avenue, Columbus, Ohio, 43202, USA.
authors.forename: Samantha E
authors.initials: SE
authors.lastname: Brown-Xu
authors.affiliation: The Ohio State University, Department of Chemistry and Biochemistry, 100 W. 18 Avenue, Columbus, Ohio, 43202, USA.
authors.forename: Malcolm H
authors.initials: MH
authors.lastname: Chisholm
authors.affiliation: The Ohio State University, Department of Chemistry and Biochemistry, 100 W. 18 Avenue, Columbus, Ohio, 43202, USA.
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Durr
authors.affiliation: The Ohio State University, Department of Chemistry and Biochemistry, 100 W. 18 Avenue, Columbus, Ohio, 43202, USA.
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Spilker
authors.affiliation: The Ohio State University, Department of Chemistry and Biochemistry, 100 W. 18 Avenue, Columbus, Ohio, 43202, USA.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Young