Studies of fluorescent dyes: part 2. An investigation of the synthesis and electronis spetral properties of substituted 3-(2'-benzimidazoyl)coumarins

摘要

A series of 3-(2'-benzimidazolyl) coumarins containing a variety of substituents in the benzene ring of teh coumarin system have beens ynthesized and their spectral properties investigated. The results of PPP molecular orbital calculations, uing previously optimised parameters, were found to provide a reasonable account of the electronic absorption spectra for this series of dyes, except for some compound which are likely to be non-planar as a result of steric congestion. The absorption and emission properties of the dyes are discussed in terms of their electronic structures.