A Diruthenium Complex of a %26quot;Nindigo%26quot; Ligand

作者：Mondal Prasenjit; Ehret Fabian; Bubrin Martina; Das Amit; Mobin Shaikh M; Kaim Wolfgang^*; Lahiri Goutam Kumar

来源：Inorganic Chemistry, 2013, 52(15): 8467-8475.

DOI：10.1021/ic400390b

The compound ((mu-Nindigo)[Ru(acac)(2)](2)} = 1, H-2(Nindigo) = indigo-N,N%26apos;-diphenylimine and acac(-) = 2,4-pentanedionate, has been structurally characterized in the rac form, which exhibits two edge-sharing six-membered chelate rings involving ruthenium, and the former beta-diketiminato functions with a twist angle of 33.9 degrees around the central C-C bond. The metric parameters suggest a neutral pi acceptor bridge containing coupled s-trans configurated alpha-diimines, which are coordinated by two ruthenium(II) centers. DFT calculations confirm the experimental structure and oxidation state assignment of the rac form; both diastereoisomers are present in solution according to H-1 NMR spectroscopy. A very intense long-wavelength MLCT absorption at 630 nm (epsilon = 66 800 M-1 cm(-1)) and a weaker near-IR band at 1120 nm (epsilon = 3000 M-1 cm(-1)) are observed for the CH3CN solution. Reversible one-electron reduction and oxidation steps were studied by cyclic voltammetry, differential pulse voltammetry, EPR, and UV-vis-NIR spectroelectrochemistry to exhibit metal-centered oxidation and mixed metal/ligand-centered reduction. These results are supported by TD-DFT calculations of the species rac- or meso-1(n), n = 3+, 2+, +, 0, -, 2-.

• 出版日期2013-8-5