Synthesis of new hole-transporting molecular glass with pendant carbazolyl moieties

The synthesis and properties of amorphous hole-transporting 4,4′-bis[11-carbazol-9-yl)-6,8,10-tri(carbazol-9-methyl)-3-hydroxy-5,7,9-trioxa-1-thia]thiobisbenzene with two end and six pendant carbazolyl moieties, separated from the main chain by CH₂ spacers, is reported. It was prepared by a multistep synthesis route from 1,6-di(carbazol-9-yl)-5-(carbazol-9-methyl)-4-oxa-2-hexanol glycidyl ether. Glass transition temperatures of intermediate and final products established by differential scanning calorimetry are reported. The hole drift mobility, measured by the time of flight technique, in this well defined molecular glass depends little on the strength of the electric field and exceeds 10⁻⁵ cm² V⁻¹ s⁻¹. The ionization potentials measured by electron photoemission method, light absorption and fluorescence spectra are closed to those reported for the other organic photoconductors containing electronically isolated carbazole moieties.     

Investigation of the monomeric and oligomeric molecular forms of human growth hormone and poly-L-lysine using fluorescence anisotropy measurement method

Summary This work illustrates the usefulness of fluorescence anisotropy measurement using a long-lifetime fluorescence label bis-(bipyridine)-5-(isothiocyanatophenanthrolin)-Ru(PF^6-)₂ for the investigation of large macromolecules - human growth hormone forms with different aggregation degree and poly-L-lysine hydrobromides with different molecular weights. Three molecular forms of this hormone – monomeric and two oligomeric (with polymerization degree 3 and 5) – and poly-L-lysine hydrobromides with different molecular weights were for the first time investigated using fluorescence anisotropy measurement by the constant viscosity. Fluorescence anisotropy and rotational correlation time are determined for each substance. Calculated rotational correlation times in investigated media are linear proportional to polymerization degree of molecular forms of the hormone. Relationship between rotational correlation time and molecular weight of random coil structure poly-L-lysines (with similar molecular weights) is nonlinear. It was shown what measured fluorescence anisotropy of the simple mixtures of two labeled molecular forms of the hormone well corresponds with theoretical anisotropy calculated with average values of the anisotropies of the separately investigated pure compounds.     

Synthesis of new hole-transporting molecular glasses with pendant carbazolyl-based hydrazone moieties

Synthesis, thermal, optical and photoelectrical properties of new hole-transporting molecular glasses with pendant carbazolyl-based hydrazone moieties, linked by aliphatic linking fragments, are reported. Electron photoemission spectra of the synthesized derivatives have been recorded and the ionization potentials have been established. The hole drift mobility values in compositions of the designed structures with bisphenol Z polycarbonate exceed 10^?5 cm² V^?1 s^?1 at an electric field 10⁶ V/cm.