关键词: 靛蓝, 吸收光谱, 络合物, 激发态

Abstract:

Based on the structures of the cis- and trans-indigo isomers, the possible geometries and photochemical properties of zinc-indigo complex were symmetrical investigated and analyzed by density function theory. It is predicted that there are different mechanisms for the excitation of the frontier orbitals between cis- and trans-forms, which result in the different absorption spectra for the isomers. From the configuration analyses of the Zinc-indigo isomers, it is assumed that there are three isomers for the cis- form indigo molecules working as ligand to Zinc ion, and one for trans-form. Because Zn-O₄ is the most stable isomer, a conclusion can be drawn that the isomeration of indigo may exist during complex formation. From the characteristic absorption spectra of the compounds, the possible mechanism for indigo decoloration can be predicted when it works as the indicator to detect the metallic content.

Key words: Indigo, Absorption spectrum, Complex, Excited state