Fluorescence and phosphorescence spectra and the decay profiles of both these emissions have been investigated for the polycrystals of phenanthridine and 7,8-benzoquinoline, in the liquid helium (5 K) - room temperature range. These two monoazaderivatives of phenanthrene, which differ only by the position of N-heteroatom in the aromatic ring skeleton of phenanthrene, were found to exhibit very different fluorescence spectra, which also differ greatly in their temperature behavior. Supplementary investigations of the fluorescence of single crystals of 7,8-benzoquinoline have supported classification of observed fluorescence as an excimer fluorescence (caused by the specific arrangement of molecules of 7,8-benzoquinoline in the crystal). In contrary fluorescence of phenanthridine crystals is of the monomeric type. Phosphorescence spectra observed for the crystals of both molecules are very similar, but their temperature dependence is also different. This may be considered as an indication of a different physical mechanism of nonradiative intersystem crossing processes, which are operating between the lowest excited singlet state and the lowest excited triplet state in the crystals of both molecules.
Macrocyclic and macropolycyclic ligands incorporating heteroaromatic N-oxides (3,3'-biisoquinoline-2,2'-dioxide) form strongly luminescent complexes with lanthanide ions: Eu(III) and Tb(III). Most of these complexes are stable water solutions, with excellent luminescent properties, regarding luminescence lifetimes in the range of 0.2-0.7 ms, and the quantum yields for emission up to 0.25. Several complexes are stable also in the presence of affecting ions, such as Ca(II), or phosphates. These features make them attractive as potential fluorescent labels for time-resolved fluoroimmunoassays.
Langmuir and Langmuir-Blodgett films of some organic dyes (perylene-like dyes, derivatives of 4-amino-naphthali-mide, derivatives of naphthoylene-benzi-mida-zole, azo dyes) and their mixtures with thermotropic liquid crystal or arachidic acid have been investigated. Surface pressure as a function of the mean molecular area for the Langmuir films were measured and information about organization of molecules at the air-water interface has been obtained. Absorption spectra in situ for the Langmuir films and both absorption and fluorescence spectra for Langmuir-Blodgett films were recorded. The results obtained from spectroscopic studies have led to conclusions about formation of self-aggregates of dye molecules, both in ground and excited states, at the phases interfaces.
The magnetic properties of C_{60}Fe_{x} resemble spin glass with the freezing onset above 200 K. The unusual magnetization behavior at intermediate temperatures is ascribed to bonds reorganization.
Slow dynamics of the initially photoinduced state has been observed by the pump-probe type time-resolved reflection spectroscopy in the charge separated phase of the half-filled strong dimer system, Et_2Me_2Sb[Pd(dmit)_2]_2 (dmit = 1,3-dithiol-2-thione-4,5-dithiolate). We have succeeded to reproduce the probe photon energy dependence of the time profile qualitatively in the time delay range from 10 ps to 1 ns assuming the dynamical expansion of the domain of the photo-induced dimer-Mott insulating phase in the host charge-separated one.
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