Synthesis and absorption spectra of some novel hetaryldisazocalix[4]arene derivatives

Abstract

In this study, a convenient method for the synthesis of thirteen novel disazo dyes containing 25,26,27-tribenzoyloxy-28-hydroxycalix[4]arene have been described. 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrahydroxycalix[4]arene, 25,26,27,28-tetrahydroxycalix[4]arene and 25,26,27-tribenzoyloxy-28-hydroxycalix[4]arene were synthesised based on previously published literature. 2-Arylhdrazone-3-ketiminobutyronitriles were synthesised and reacted with hydrazine hydrate to afford the corresponding 5-amino-4-arylazo-3-methyl-1H-pyrazoles. Thirteen novel hetaryldisazocalix[4]arene derivatives were achieved by diazotisation of 5-amino-4-arylazo-3-methyl-1H-pyrazoles using nitrosylsulphuric acid, coupled with 25,26,27-tribenzoyloxy-28-hydroxycalix[4]arene. The obtained hetaryldisazocalix[4]arene dyes were characterised based on Fourier Transform-infrared, proton nuclear magnetic resonance and mass spectroscopic techniques, as well as elemental analysis. The solvatochromic behaviour of these dyes in various solvents was examined. Acid-base effects on the visible absorption maxima of the dyes were also reported. © 2011 The Authors. Coloration Technology © 2011 Society of Dyers and Colourists.