The molecular structures and the absorption maxima of the H-chromophores of the indigoid dyes

✍ Scribed by P. C. Chen

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 450 KB
• Volume: 16
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.540160804

✦ Synopsis

The molecular structures of the H-chromophore of the indigoid dyes and five other isomers are studied by ab initio MP2/6-31 + G*//HF/6-31 + G* method.

The bond angles are affected by the r-electron conjugation. The molecular structures of the H-chromophores and indigoid dyes indicate that the benzene rings and the five-membered rings are structurally important. The absorption maxima of the H-chromophores are successfully calculated by CI-singles-MP2/6-31 + G* theory for the first time and correspond to the HOMO, LUMO transition. All these transitions are the r-r* transitions. Like the indigoid dyes, trans isomers have the bathochromic shifts of the absorption maxima, and the bathochromic shifts are found with the best donor group of -NH. From these calculations, the absorption maxima of some indigoid dyes can be explained by their H-chromophores qualitatively. 0 1995 by John Wiley & Sons, Inc.

* Six pages of the geometries and total atomic charges of the H-chromophores with different donors are available from the ity.

author upon request.