Studies on transition-metal oxo and nitrido complexes. Part 9. Periodato and tellurato oxo-ruthenium complexes as organic oxidants. X-Ray crystal structure of trans-NaK5[RuO2(HIO6)2]·8H2O

Abstract

Salts of the anion trans-[RuO₂(HIO₆)₂]^6–, earlier formulated as [Ru(OH)₂(IO₆)₂]^6–, and of [RuO₂(H₂TeO₆)₂]^6– have been prepared, and the X-ray crystal structure of the complex trans-NaK₅[RuO₂(HIO₆)₂]·8H₂O determined [monoclinic, space group C2/c, a= 26.869(14), b= 7.359(2), c= 11.471(3)Å, β= 94.47(3)°, Z= 4, R= 0.059]. Vibrational and electronic spectra for these diamagnetic ‘ruthenyl’ complexes are also reported. The periodato complexes function as overall six-electron oxidants in aqueous solution, converting primary alcohols to carboxylic acids and secondary alcohols to ketones; such reactions can be rendered catalytic if periodate is used as a co-oxidant. The tellurato complex functions as a two-electron oxidant for alcohols.