Synthesis, crystal structure, computational and photophysical studies of new hydrazono-thiazole derivatives decorated with N-methyl tetrahydrocarbazole pendant

2,3-Dihydro-1H-carbazol-4(9H)-one, obtained from 2,3-Dichloro-5,6-Dicyanobenzoquinone (DDQ) oxidation of tetrahydrocarbazole, on methylation with N, N-dimethylformamide dimethyl acetal (DMF-DMA) furnish N-methyl derivative. The thiosemicarbazone of N-methyl derivative on reaction with 2-bromopropionic acid, ethyl bromopyruvate and dimethyl acetylenedicarboxylate (DMAD) afford hydrazono-thiazolidin-4-one derivatives with tetrahydrocarbazole pendant. X-ray diffraction and DFT studies of (Z)-5-methyl-2-((E)-(9-methyl-2,3-dihydro-1H-carbazol-4(9H)-ylidene)hydrazono)thiazolidin-4-one 5 have been reported. The reaction with dimethyl acetylenedicarboxylate (DMAD) and ethyl bromopyruvate take place without any catalyst and organic solvent. The photophysical properties of these compounds were studied by means of UV/visible absorption spectroscopy and fluorescence spectroscopy.