Title
Photophysics and Photochemistry of 2,2'-Bipyridine and 1,10-Phenanthroline Complexes of Vanadium(II)
Document Type
Article
Publication Date
1-1-1986
Abstract
The lifetimes of the lowest energy excited states of V(bpy)32+ (bpy = 2,2/-bipyridine) and V(phen)32+ (phen = 1,10-phenanthroline) are 500 ps and 1.8 ns, respectively, in ethanol at room temperature. These lifetimes are much shorter than those for the isoelectronic chromium(III) complexes. The lowest energy excited states in the vanadium systems are probably either 2E/2T1 or quartet MLCT states. Electrode potentials for the V(NN)33+/2+ couples are approximately 0.09 (NN = bpy) and 0.13 V (NN = phen) in CH3CN vs. Fc/Fc+ (Fc = ferrocene), based on cyclic voltammetry data. Irradiation of V(phen)32+ in its lowest energy electronic absorption band λmax=640 nm) in the presence of various electron acceptors results in one-electron oxidation and ultimate formation of (phen)2V(μ-OH)2V(phen)24+. Similar photoredox processes are observed for V(bpy)32+. The photooxidation mechanism involves oxidative quenching of the V(NN)32+ excited state, followed by hydrolysis and dimerization of V(NN)33+. © 1986, American Chemical Society. All rights reserved.
Publication Source (Journal or Book title)
Inorganic Chemistry
First Page
1867
Last Page
1871
Recommended Citation
Shah, S., & Maverick, A. (1986). Photophysics and Photochemistry of 2,2'-Bipyridine and 1,10-Phenanthroline Complexes of Vanadium(II). Inorganic Chemistry, 25 (11), 1867-1871. https://doi.org/10.1021/ic00231a031