Isomeric separation in donor–acceptor systems of Pd(II) and Pt(II) and a combined structural, electrochemical and spectroelectrochemical study

0369089 - ÚFCH JH 2012 RIV GB eng J - Journal Article
Deibel, N. - Schweinfurth, D. - Fiedler, Jan - Záliš, Stanislav - Sarkar, B.
Isomeric separation in donor–acceptor systems of Pd(II) and Pt(II) and a combined structural, electrochemical and spectroelectrochemical study.
Dalton Transactions. Roč. 40, č. 38 (2011), s. 9925-9934. ISSN 1477-9226. E-ISSN 1477-9234
R&D Projects: GA MŠMT LD11086
Institutional research plan: CEZ:AV0Z40400503
Keywords : electrochemistry * spectroelectrochemistry * palladium
Subject RIV: CG - Electrochemistry
Impact factor: 3.838, year: 2011

Compounds of the form [(pap)M(Q2−)] (pap = phenylazopyridine; Q = 3,5-di-tert-butyl-benzoquinone, M = Pd, 1a and 1b, M = Pt, 2a and 2b; Q = 4-tert-butyl-benzoquinone, M = Pd, 3a and 3b; M = Pt, 4a and 4b) were synthesized in a one-pot reaction. The geometrical isomers, which are possible because of the built in asymmetry of these ligands, have been separated by using different temperatures and variable solubility. Structural characterization of 1b shows that the metal centers are in a square planar environment, the pap ligand is in the unreduced neutral state and the quinones are in the doubly reduced, Q2− catecholate form.Cyclic voltammetric measurements on the complexes display two one-electron oxidations and two one-electron reductions. EPR and vis-NIR spectra of the one-electron oxidized forms of the complexes indicate that the first oxidation takes place on the Q2− ligands to produce a metal bound semiquinone (Q−) radical.
Permanent Link: http://hdl.handle.net/11104/0203238