Solvent Effects on the Spectral Properties of the Methine Dyes

Recently, methine dyes have attracted interest for their possible application in display devices [1, 2 ] . A liquid crystal display based on the ability of "guest"' pleochroic dyes to align parallel to the "host" liquid crystal was first described by Heilmeier and Zanoni [3 ] . Since then the basic properties of "guest-host" type liquid crystal display devices and the effects of various parameters on their colour display properties have been clarified [1, 2 ] . Unfortunately, the main theoretical problems concerning the molecular interactions between the liquid crystal matrix and the dye molecules remain still open [4, 5 ] . The present study deals with the spectral effects of solvation, complexation and aggregation of two representative methine dyes.