SYNTHESIS, CHARACTERIZATION AND UV-VIS PROPERTIES OF AZOCALIX[4]CROWNS

This article describes the synthesis, structure end UV properties of a zocalixcrowns in which the photoresponsive trans-cis azo benzene unit has been introduced in the glycolic chains of the calix[4]crowns. The synthesis proceeded via the selective- 1,3 O-dialkylation of calix[4] arene with glycolic chains terminated by nitrophenyl residues. After r eduction of the nitro groups into amino functions, intramolecular oxid ative coupling produced the capping of the calixarene. The synthetic a pproaches and the cis-trans structure of these new ligands are discuss ed and full details on syntheses and structural data are given. A prel iminary example of cesium complexation by one of the ligands is propos ed.