Abstract
The reduction reaction of the Cu(II)-pitn complex (pitn = 1,3-di(pyridine-2-carboxaldimino)propane) by decamethylferrocene [Fe(Cp∗)2] was examined in acetonitrile. The observed pseudo-first-order rate constants exhibited saturation kinetics with increasing excess amount of [Fe(Cp∗)2]. Detailed analyses revealed that the reaction is controlled by a structural change prior to the electron transfer step, rather than a conventional bimolecular electron transfer process preceded by ion pair (encounter complex) formation. The rate constant for the structural change was estimated to be 275 ± 13 s-1 at 298 K (δH∗= 33.3 ± 1.0 kJ·mol-1, δS∗= 86 ± 5 J·mol-1·K-1), which is the fastest among gated reactions involving CuN4 complexes. It was confirmed by EPR measurement and Conflex calculations that the dihedral angle between the two N-N planes is significantly large (40°) in solution whereas it is merely 17.14° in the crystal.
Original language | English |
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Pages (from-to) | 1479-1486 |
Number of pages | 8 |
Journal | Journal of Solution Chemistry |
Volume | 43 |
Issue number | 9-10 |
DOIs | |
Publication status | Published - 2014 Oct 21 |
Keywords
- Acetonitrile
- Cu(II)(pitn)
- Cyclic voltammetry
- Decemethylferrocene
- Rate constants
ASJC Scopus subject areas
- Biophysics
- Biochemistry
- Molecular Biology
- Physical and Theoretical Chemistry