Spectroscopic and thermal properties of newly mixed azocalix[4]arene ester derivatives

• In this work, some interesting data on newly synthesized novel azocalixarene-esters have been presented.
• These compounds may have significance in synthesizing new, novel organic materials.
• In the IR and 1H NMR spectrum of compounds were not detected –NH peaks so all azocalix[4]arenes exist in azo form.

The mono-, di-, tri-, and tetra-acryloyl esters of p-chloroazocalix[4]arene which include the first examples of mixed azo ester dyes were synthesized by reacting acryloyl chloride with sodium salts of p-chloroazocalix[4]arene in tetrahydrofuran with inert atmosphere. Diazonium salt of p-chloroaniline was synthesized by using n-amlynitrite and coupled with calix[4]arene in anhydrous condition. This is the diazo coupling reactions used for the first time for synthesized azocalix[4]arene. The characterization of synthesized compounds by spectroscopic methods revealed that azocalix[4]arenes adopt a cone conformation if they contain at least one free phenolic group. The structures of these compounds have been characterized by infrared (IR), ultraviolet–visible (UV–VIS), proton nuclear magnetic resonance (1H NMR) and carbon nuclear magnetic resonance (13C NMR). Differential thermal analysis (DTA), thermogravimetry (TG) and derivative thermogravimetry (DTG) were used to determine the thermal behaviors of the compounds.

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