Synthesis and photophysical properties of bipolar low-molar-mass amorphous materials

Bipolar molecules containing electron-accepting (trioxothioxanthene, benzotriazole, trinitrophenol) and electron-donating (carbazole) moieties were synthesised and characterised by nuclear magnetic resonance, infrared spectroscopy, and mass spectrometry. The thermal, optical and photoelectrical properties of the synthesised compounds are reported. Two synthesised compounds 6-(9H-carbazole) hexyl 9,10,10-trioxo-9H-thioxanthen-3-oate and 1-(9H-carbazolyl)-3-(2,4,6-trinitrophenoxy)-2-propanol form glasses with glass transition temperatures above room temperature i.e. 45 and 59 °C, respectively, as established by differential scanning calorimetry. The ionisation potentials of these compounds measured by electron photoemission technique are 5.77 and ca. 6 eV, respectively.