Charge transfer excitation of aqueous benzylpentacyanocobaltate(III) led to a redox reaction with formation of Co(CN)53- and benzyl radicals in the primary photochemical step. In the absence of oxygen the benzyl radicals dimerized to bibenzyl. At 313 nm irradiating wavelength the quantum yield was 0,13 ± 0,02. In the presence of air oxygen was apparently inserted into the carbon-cobalt bond with the intermediate formation of [Co(CN)5O2CH2C6H5]3-, which decomposed to give Co(CN)5H2O2- and benzaldehyde (ɸ = 0,15 ± 0,02). The significance of these results is discussed with regard to the photochemistry of acidopentacyanocobaltates(III) and organocobalamins.
© 1946 – 2014: Verlag der Zeitschrift für Naturforschung
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.