Article ID Journal Published Year Pages File Type
177515 Dyes and Pigments 2010 18 Pages PDF
Abstract

To examine the strengths and limitations of the time-dependent density functional theory in calculating the absorption wavelengths of dye, 130, non-radical, radical and biradical coloured organic compounds, including perylenimide, porphyrin, azobenzene, quinone, croconaine, squaraine and push–pull-type colorants, were randomly selected. The first intense electronic transitions were satisfactorily calculated using time-dependent density functional theory. Whilst polymethine dyes behaved exceptionally, the calculated transition energies for cyanines, oxonols and various related dyes were systematically too large. Broken-symmetry unrestricted density functional calculations revealed the biradical character of several quinoid compounds derived from p-quinodimethane as well as that of some non-Kekulé-type structures.

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Physical Sciences and Engineering Chemical Engineering Chemical Engineering (General)
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