Synthesis and characterization of deep-coloured squarylium dyes for laser optical recording media

摘要: Abstract The synthesis and characterization of some deep-coloured squarylium dyes was studied with respect to the development media in optical recording systems. reaction 3-ethyl-2-methylbenzothiazolium iodide squaric acid benzene/1-butanol gave 2,4-bis[(3-ethyl-2-benzothiazolylidene)methyl]-cyclobutadienylium-1,3-diolate (λ max 667nm) its adduct type compound as by-product. latter a new had an absorption maximum at 796 nm. Similarly 2,4-bis[(3-ethyl-2-benzoselenazolylidene)methyl] cyclobutadienylium-1,3-diolate also synthesized from 3-ethyl-2-methylbenzoselenazolium acid. This 815 nm, i.e. infrared wavelength region. Thus, these iodine atom butoxy group generally absorbed much longer (120–130 nm) than corresponding parent dyes. structures is discussed on basis IR ESCA analyses.