Spectroscopic Investigation of Electronic States of the CrO42 Ion in the Visible and Ultraviolet Absorption Region

Low temperature electronic spectra of potassium chromate: pure K2CrO 4 single crystal and the 1:20 solid solution of K2CrO 4 in K2SO4 have been analyzed in detail using filtration and deconvolution methods. The 14000-19000 cm-1 spectral region of crystal has been found to contain extremely low intensity bands which have been assigned to spin and symmetry forbidden CrO charge transfer (CT) transitions. Surprisingly, the whole solid solution spectrum in the 19000-50000 cm-1 energy range was found to be composed exclusively from vibronic transitions with the coupled n1 Cr-O mode.