Electronic absorption spectra and the structure of the ligand in metal complexes with purpurin

Purpurin complexes with metals are formed due to metal coordination at the peri- or ortho-hydroxycarbonyl group involving anthraquinoid tautomers. The πl,π*bands of metal purpurinates correspond to 1,10- and 1,4-anthraquinoid anions, 9,10-anthraquinoid structures are not typical of them. © 2005 Pleiades Publishing, Inc.