SYNTHESIS AND SPECTROSCOPIC STUDIES OF NOVEL PHOTOCHROMIC BENZODITHIACROWN ETHERS AND THEIR COMPLEXES

New styryl dyes containing the benzodithia-18-crown-6 fragment have be en synthesized and their photoisomerization reactions and complexes wi th Hg2+ and Ag+ cations have been investigated by steady-state electro nic and resonance Raman spectroscopy. (4-Formylbenzo)dithia-18-crown-6 , N-carboxypropyl- and N-carboxybutyl-2-methylbenzothiazolium bromides have also been prepared as intermediates for the styryl dye syntheses . Changes in vibrational resonance Raman spectra observed on complexat ion with Ag+ and Hg2+ cations or on variation of solvent polarity have been correlated with changes in the UV-VIS absorption maxima of the d yes. Preliminary assignments of the observed Raman bands to particular vibrations are made.