%0 Generic %A Maurer, Jörg %A Linseis, Michael %A Sarkar, Biprajit %A Schwederski, Brigitte %A Niemeyer, Mark %A Kaim, Wolfgang %A Záliš, Stanislav %A Anson, Chris %A Zabel, Manfred %A Winter, Rainer F. %D 2008 %T Ruthenium Complexes with Vinyl, Styryl, and Vinylpyrenyl Ligands:  A Case of Non-innocence in Organometallic Chemistry %U https://acs.figshare.com/articles/dataset/Ruthenium_Complexes_with_Vinyl_Styryl_and_Vinylpyrenyl_Ligands_A_Case_of_Non_innocence_in_Organometallic_Chemistry/2963806 %R 10.1021/ja075547t.s003 %2 https://acs.figshare.com/ndownloader/files/4662907 %K Experimental findings %K Carbonyl band shifts %K pyrenyl %K HOMO increases %K phosphine ligands %K PR %K hexenyl complexes %K hexenyl ligand %K Organometallic ChemistryWe %K vinyl ligands %K coordination number %K vinyl ligand increases %K vinyl complexes %K Ruthenium Complexes %K CH %K CO %K ESR spectra %K organometallic ruthenium chemistry %K vinyl ligand %K coordination site %K substituent R %K anodic oxidation processes %K R changes %K peak potentials show %K cations display %X We herein describe a systematic account of mononuclear ruthenium vinyl complexes L−{Ru}−CHCH−R where the phosphine ligands at the (PR‘3)2Ru(CO)Cl{Ru} moiety, the coordination number at the metal (L = 4-ethylisonicotinate or a vacant coordination site) and the substituent R (R = nbutyl, phenyl, 1-pyrenyl) have been varied. Structures of the enynyl complex Ru(CO)Cl(PPh3)212-nBuHCCHC⋮CnBu), which results from the coupling of the hexenyl ligand of complex 1a with another molecule of 1-hexyne, of the hexenyl complexes (nBuCHCH)Ru(CO)Cl(PiPr3)2 (1c) and (nBuCHCH)Ru(CO)Cl(PPh3)2(NC5H4COOEt-4) (1b), and of the pyrenyl complexes (1-Pyr-CHCH)Ru(CO)Cl(PiPr3)2 (3c) and (1-Pyr-CHCH)Ru(CO)Cl(PPh3)3 (3a-P) have been established by X-ray crystallography. All vinyl complexes undergo a one-electron oxidation at fairly low potentials and a second oxidation at more positive potentials. Anodic half-wave or peak potentials show a progressive shift to lower values as π-conjugation within the vinyl ligand increases. Carbonyl band shifts of the metal-bonded CO ligand upon monooxidation are significantly smaller than is expected of a metal-centered oxidation process and are further diminished as the vinyl CHCH entity is incorporated into a more extended π-system. ESR spectra of the electrogenerated radical cations display negligible g-value anisotropies and small deviations of the average g-value from that of the free electron. The vinyl ligands thus strongly contribute to or even dominate the anodic oxidation processes. This renders them a class of truly “non-innocent” ligands in organometallic ruthenium chemistry. Experimental findings are fully supported by quantum chemical calculations:  The contribution of the vinyl ligand to the HOMO increases from 46% (Ru-vinyl delocalized) to 84% (vinyl dominated) as R changes from nbutyl to 1-pyrenyl. %I ACS Publications