Synthesis Of Rhodanine Blue Laser Merocyanine Dyes As Well As Their Spectral Properties

The blue laser organic recording dyes have attracted wide attention due to their core role in the super-high density recording technology.There are many literatures on their synthesis and applications.In this paper,the preparation and application of blue laser organic recording dyes,such as porphyrin dyes,azo dyes,cyanine dyes,stilbene dyes and coumarin derivatives are presented.Their research trends are prospected.A series of 2-methylthio quaternary salts were synthesized.By both solvent method and microwave method,6 different rhodanine merocyanine dyes were synthesized using rhodanine, 2-methyithio quaternary salts and 1H-indole-3-carbaldehyde as starting materials.The products were identified by ¹H NMR,1R,UV-Vis spectra and elemental analysis.3 different dyes were characterized and analyzed by X-ray diffraction.The UV-vis spectra of 6 rhodanine blue laser merocyanine dyes in different solvents and film were investigated.The results indicated that the profile was not changed in different solvents,but the absorbance was effected.With the increasing of refractive index of solvents, theλ_max of these dyes had a red-shift.Theλ_max of dye-films had a red-shift about 10nm.The fluorescence spectra of 6 dyes was detected in the solvent of chloroform,DMSO, water,acetone,ethanol and methanol.The results suggested that the fluorescenceλ_em of these dyes was blue-green ranging from 440-560nm.Theλ_em was the longest in water for the same dye.The fluorescence intensity in the solvent of DMSO and methanol was stronger than in other solvents.Stokes shifts were effected by the volume of dye molecular.Stokes shifts were wider as the enlarging of the volume of dye molecular.