The ground state of copper acetylacetonate

Abstract

The crystal spectra of copper acetylacetonate first measured by Ferguson are re-interpreted using the results of an accurate crystal structure determination. The principles involved in such an analysis are fully discussed. The analysis does not provide unambiguous assignments of the observed bands because of the unfortunate orientation of the molecule in unit cell and also because it is not known which vibrations are effective in promoting the transitions. Therefore, there is now no reason to discard the ground state assignment based on the crystal field theory and results of electron spin resonance. The spectral data in solutions is reviewed and tentative assignments of the bands are proposed.