Photoelectron spectra of aluminum complexes with 8-oxyquinoline (Alq 3) and zinc complexes with N, N′-(o-phenylene)-bis(salicylidenediamine) (ZnSaloph) were measured on a photoelectron spectroscopy station at the Kurchatov Centre for Synchrotronic Radiation over the range of photon energies from 10 to 100 eV. Thin films of these compounds (∼20 nm thick) prepared by thermal evaporation onto glass substrates covered with transparent electroconductive layer of solid solution of tin and indium oxides (In2O3, SnO2, ITO) were used as the objects of this study. The spectra of the valence band of these compounds and Al 2p level were measured. The data of quantum chemical calculations of the electronic structure obtained by the density functional theory are in good agreement with the experimental photoelectron spectra. Analysis of performance efficiency of the device was carried out on the basis of the results of calculation. This procedure does not result in decomposition of samples in the process of investigation and may be used for studying the electronic structure of coordination compounds with organic ligands in films.

A multiscale method is proposed for modeling elements of optical chemosensors based on photonic crystals. The method is based on the first-principles quantum-chemical and electrodynamic calculations. A technique is proposed that takes into account electromagnetic emission sources in the framework of the finite-difference time-domain method. An end-to-end simulation of fluorescence in a photonic crystal is performed: the absorption and emission spectra of a dye on a substrate are calculated by quantum chemistry, and it is shown how the dye emission spectra are modified in a three-dimensional photonic crystal.

Tetradentate Schiff bases (H(2)L(i)), derivatives of salicylic aldehyde (H(2)L(1), H(2)L(2)) or o-vanillin (H(2)L(3), H(2)L(4)) with ethylenediamine or o-phenylenediamine as a bridge, and their zinc complexes were studied experimentally and theoretically in view of their possible application as emitters in organic light emitting diodes (OLEDs). The composition of thin films of the complexes was analyzed using a combination of different experimental and molecular modeling techniques taking into account changes in the Gibbs free energy of dehydration and dimerization reactions. The absorption spectra of the initial Schiff bases were investigated in methanol solutions, while the absorption spectra of their zinc complexes were investigated in thin films. Experimental results of elemental analysis, IR spectroscopy, laser desorption/ionization mass spectrometry (LDI MS), and X-ray diffraction as well as theoretical analysis of electronic absorption spectra by the quantum-chemical TD DFT method demonstrate that thin films of the zinc complexes contain binuclear anhydrous molecules. This conclusion should be taken into account when considering both transport and luminescence properties of these complexes in OLED heterostructures. A comparison of the results of CIS, TD DFT/PBE, and TD DFT/PBE0 calculations reveals the crucial importance of the inclusion of the exact exchange in the E(XC) functional for the further correct description of potential energy surfaces of excited states for the systems studied.

The relative stability of the trans -and cis -isomers of 3,3′-diethylthiacarbocyanine (Dye1) and 3,3′-diethyl-9-methylthiacarbocyanine (Dye2) 1 , as well as sections of the potential energy surfaces along the internal coordinate of the isomerization reaction, were studied using the density functional theory. Calculation of the minimum energy pathway for the isomerization reaction showed that the barrier for rotation about the C 8 –C 9 bond is higher for Dye1 than for Dye2. Local minimums were found for the singlet excited state of the 8,9- cis -and trans -isomers of the dyes. In the case of the trans -isomers, substantial changes in the dye structure do not occur and the local minimum of the excited state corresponds to the geometry of the starting trans -isomers, which favors efficient fluorescence. A search for the nearest local minimum of the singlet excited state of the 8,9- cis -isomers leads to structures, which differ significantly from the starting structures, and the intensity of the S 1 → S 0 transition in those structures appears to be practically zero. The results are in agreement with experimental data on the absorption, fluorescence, and fluorescence excitation spectra of the dyes.

Complexes of N-arylaza-15(18)-crown-5(6) ethers with K+ and Na+ are studied by the density functional method with and without regard for the specific solvation of the cation by water molecules in the macrocycle cavity. The effects of solvation on the stability of different complex conformers are studied through explicitly including up to four water molecules in the complex. Two types of conformations are considered, namely, the axial type characterized by the existence of a metal–nitrogen bond and the equatorial type, in which this bond is not formed. The selectivity of the arylaza-15(18)-crown-5(6) ethers for Na+ and K+ is estimated using the bonding energy. It is found that both azacrown ethers are selective for sodium, although interaction with water impairs the selectivity.