Abstract

p-Tetrakis(4-nitrophenylazo)tetrahydroxytetrathiacalix[4]arene and p-tetrakis(phenylazo)tetrahydroxytetrathiacalix[4]arene were prepared and fully characterized using ¹H and ¹³C NMR, mass spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The solid-state structure of p-tetrakis(4-nitrophenylazo)tetrahydroxytetrathiacalix[4]arene was investigated by single crystal X-ray diffraction. It crystallized in the triclinic system (space group: P). z-Scan experiments were performed on the p-tetrakis(4-nitrophenylazo)tetrahydroxytetrathiacalix[4]arene showing non linear absorption due to two photon absorption with a TPA cross-section of about 50 × 10⁻⁵⁰ cm⁴ s per photon. Optical power limiting measurements on the p-tetrakis(phenylazo)tetrahydroxytetrathiacalix[4]arene at 532 nm (48% linear transmission) was found to limit the energy to ∼9 µJ.