Invariant Oxidation State of Copper but not of Ruthenium in Complexes with Noninnocent N-(2-Methyl-5,8-dioxo-5,8-dihydroquinolin-7-yl)acetamide: A Combined Structural, Electrochemical and Spectroelectrochemical Investigation

0359540 - ÚFCH JH 2012 RIV DE eng J - Journal Article
Paretzki, A. - Das, H. S. - Weisser, F. - Scherer, T. - Bubrin, D. - Fiedler, Jan - Nycz, J. E. - Sarkar, B.
Invariant Oxidation State of Copper but not of Ruthenium in Complexes with Noninnocent N-(2-Methyl-5,8-dioxo-5,8-dihydroquinolin-7-yl)acetamide: A Combined Structural, Electrochemical and Spectroelectrochemical Investigation.
European Journal of Inorganic Chemistry. -, č. 15 (2011), s. 2413-2421. ISSN 1434-1948. E-ISSN 1099-0682
R&D Projects: GA ČR GA203/09/0705; GA ČR GA203/08/1157
Institutional research plan: CEZ:AV0Z40400503
Keywords : copper * ruthenium * quinones
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 3.049, year: 2011

The compounds [(dppf)Cu(L)](BF4) (1[BF4]) [dppf = 1,1′-bis(diphenylphosphanylferrocene), L = N-(2-methyl-5,8-dioxo-5,8-dihydroquinolin-7-yl)acetamide] and [(acac)2Ru(L)] (2) (acac = acetylacetonato) were prepared from the reactions of [Cu(dppf)(CH3CN)2](BF4) or [Ru(acac)2(CH3CN)2], respectively with L. Structural characterization of 1[BF4] shows a distorted tetrahedral coordinated copper center. Both complexes show one-electron reversible oxidation as well as reduction processes in their cyclic voltammogram. The first oxidation process of 1[BF4] leads to absorptions at around 900 nm in the UV/Vis/NIR spectrum and results in an EPR silent species up to 110 K thus indicating a dppf-centered oxidation. The reduction processes of 1[BF4] show features in the UV/Vis/NIR, IR as well as EPR spectrum that are compatible with L-centered redox processes. In contrast to this, the ruthenium complex 2 shows metal-centered spin in both the one-electron oxidized as well as reduced forms.
Permanent Link: http://hdl.handle.net/11104/0197314