Halogen

The thermoluminescence studies of poly(9-vinylcarbazole) (PVK) modified by substitution with halogens (Cl, Br, I) carried out in 15-325 K temperature range are reported. Spectral analyses of the thermoluminescence at different temperatures are discussed and compared with the analogues results obtained for unsubstituted PVK. It has been found that introduction of halogen atoms to the carbazol-9-yl groups does not change the thermoluminescence mechanisms characteristic of PVK, but reduces the probability of excimer formation due to a steric hindrance. For all the investigated poly(9-vinylhalogenocarbazole)s, the bathochromic shift in the emission spectra was observed, due to mesomeric effects of the halogen atoms on the p-carbazolic system.

Novel supramolecular self-assemblies of nitroxide free radicals via noncovalent halogen bonding are synthesised. A directional NO Å Á Á ÁI interaction is observed in a one-dimensional coordination polymer consisting of alternating electron donor and acceptor molecules.