Redox-Rich Spin-Spin-Coupled Semiquinoneruthenium Dimers with Intense Near-IR Absorption

0360223 - ÚFCH JH 2012 RIV US eng J - Journal Article
Kundu, T. - Sarkar, B. - Mondal, T. K. - Mobin, S. M. - Urbanos, F. A. - Fiedler, Jan - Jimenez-Aparicio, R. - Kaim, W. - Lahiri, G. K.
Redox-Rich Spin-Spin-Coupled Semiquinoneruthenium Dimers with Intense Near-IR Absorption.
Inorganic Chemistry. Roč. 50, č. 11 (2011), s. 4753-4763. ISSN 0020-1669. E-ISSN 1520-510X
R&D Projects: GA ČR GA203/09/0705; GA MŠMT LD11086
Institutional research plan: CEZ:AV0Z40400503
Keywords : transition metal complexes * nuclear magnetic resonance * density functional theory
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 4.601, year: 2011

Using the [RuCl(mu-tppz)ClRu](2+) [tppz=2,3,5,6-tetrakis(2-pyridyl)pyrazine] platform for bridging two o-quinone/catecholate two-step redox systems (unsubstituted,Q(n), or 3,5-ditert-butyl-substituted,DTBQ(n)), we have obtained the stable complexes [(Q(center dot-))(RuCl)-Cl-II(mu-tppz)ClRuII(Q(center dot-))] (1) and the structurally characterized [(DTBQ(center dot-))(RuCl)-Cl-II(mu-tppz)ClRuII(DTBQ(center dot-))] (2). The compounds exhibit mostly quinone-ligand-based redox activity within a narrow potential range, high-intensity near-IR absorptions (lambda(max) approximate to 920 nm; epsilon > 50 000 M-1 cm(-1)), and variable intra- and intermolecular spin-spin interactions. Density functional theory calculations, electron paramagnetic resonance (EPR), and spectro-electrochemical results (UV-vis-near-IR region) for three one-electron-reduction and two one-electron-oxidation processes were used to probe the electronic structures of the systems in the various accessible valence states.
Permanent Link: http://hdl.handle.net/11104/0006474