By solid-phase synthesis from elemental Cu, Ni, Sn, and S samples Cu 2-delta NiSnS 4 (0≤delta≤0.2) was prepared. The parameters of their crystal lattice have been refined. The lifetimes of photogenerated current carriers in Cu 2-delta NiSnS 4 were estimated for the first time by the contactless time-resolved microwave photoconductivity method. This times turned out to be tau~7 ns, which is comparable with the literature data for the times in kesterites CZTS. Herewith, in kinetics of loses of photogenerated cureent carriers is observed predominance of bimolecular recombination processes over capture processes. Keywords: Cu 2-delta NiSnS 4 , onequilibrium current carriers, lifetimes, kinetics.

By solid-phase synthesis from elemental Cu, Ni, Sn, and S samples Cu2 - δNiSnS4 was prepared . The parameters of their crystal lattice have been refined. The lifetimes of photogenerated current carriers in Cu2 - δNiSnS4 were estimated for the first time by the contactless time-resolved microwave photoconductivity method. This times turned out to be τ ≈ 7 ns, which is comparable with the literature data for the times in kesterites CZTS. Herewith, in kinetics of loses of photogenerated cureent carriers is observed predominance of bimolecular recombination processes over capture processes.

Polycrystalline Cu2ZnSn(SхSe1– х)4 solid solutions have been prepared by a single-temperature method using elemental Cu, Zn, Sn, S, and Se. The chemical composition of the synthesized materials has been determined by X-ray microanalysis and their crystal structure and phase composition have been studied by X-ray diffraction and Raman spectroscopy. Using frequency-time-resolved microwave photoconductivity measurements, we examined the effect of sulfur and selenium content on photogenerated current carrier loss kinetics in the Cu2ZnSn(SхSe1– х)4 solid solutions. An increase in sulfur content has been shown to result in the formation of additional deep levels, capable of acting as electron acceptors.

By solid-phase synthesis, macrocrystalline Cu2 − δZn2 − xSnxS4 − ySey monograin powders have been prepared, the chemical composition of which was shown by XRD and Raman spectroscopy to be different in powder fractions of different sizes formed during the synthesis. The influence of synthesis conditions on the decay kinetics of photogenerated charge carriers in different fractions has been studied using the frequency–time-resolved microwave photoconductivity method. The characteristic photoresponse half-life, τ1/2, increased with increasing grain size. The smallest values of the lifetime were observed for the fraction with sizes of 50–70 μm (τ1/2 <5 ns), and the largest values were for the fraction with a grain size of 70–90 μm (τ1/2 ~ 12 ns).

A structure-property relationship was used to estimate the free energy of formation of host-guest complexes of α-cyclodextrin with monosubstituted benzene and phenol derivatives and with symmetrical 1,4-disubstituted benzene derivatives, in which various nonvalent interactions (hydrophobic, van der Waals, donor-acceptor) play a significant role. The calculated values are well consistent with the experiment.

The previously suggested quantitative structure-property relationship was used for predicting properties of aliphatic carboxylic acids. The boiling points, octanol-water partition factors (log P), and toxicities [log(1/IGC(50))] were calculated for a series of monocarboxylic, dicarboxylic, and unsaturated monocarboxylic acids. The calculated values are well consistent with the experimental data.

A property-property correlation based on the previously suggested general expression for the quantitative structure-property relationship was obtained; it allows accurate estimation of many properties of organic compounds. Its connection with the Bronsted and Hammett equations was demonstrated.

Differences in various properties of organic compounds of different classes of the same or similar composition but of different structure, as well as complexes of such compounds and transient complexes in their chemical reactions are associated with different mobility of terminal molecular fragments and can be explained in terms of the “hot termini” effect.

The quantitative structure-property relationship was used to calculate the boiling points of 74 aliphatic monohydric alcohols of various structures; the trends in the properties of isomers and their compositionally related compounds were explained with account for the “hot ends” effect.

The previously suggested quantitative structure-property relationship was applied to estimating the properties of polycyclic aromatic hydrocarbons containing from two to six benzene rings fused in various modes. For these compounds, the boiling points, retention indices, and distribution factors in the octanol-water system were calculated. The results obtained are well consistent with the experimental data.

The solubility of oxygen in organic solvents was estimated from property-property correlations.

The simple approach suggested previously for estimating properties of molecules RX was applied to constructing quantitative relationships between the structure of alkyl substituent R and the properties of stable complexes and transition states considered as supermolecules RX. The enthalpies and free energies of complexation of a series of aliphatic amines with trimethylboron, the logarithms of the relative rates of esterification of aliphatic carboxylic acids, and the Taft steric constants were calculated.

The previously suggested structure-property relationship was applied to estimating the properties of methane and silane derivatives C(Si)H e X m Y4−e−m in which substituents X and Y at the same central atom differently interact with each other. In these compounds, the two-fragment 1⋯3 interactions, multifragment interactions, and interactions corresponding to the electrostatic contribution to intermolecular interactions play a significant role. The boiling points were calculated for the F, Cl, and F,Cl derivatives of methane, silane, and methylsilanes; for the methane derivatives, the octanol-water partition coefficients (log P) systems and heat capacities at constant pressure (Cp) were also calculated. The results obtained are well consistent with the experimental data.

The quantitative structure-property relationship was applied to calculate the enthalpy of formation of aliphatic polynitro compounds, which was estimated from data for alkane molecules using appropriate corrections. Two alternatives of the suggested approach were considered, in which the molecule of a nitro compound is constructed by replacement of an H atom or CH3 group with the NO2 group in a definite position of a saturated hydrocarbon.

A simple approach to estimating properties of branched molecules is suggested: A property of any nonlinear molecule is considered as a sum of the property of the corresponding linear molecule and correction "for branching,"] determined by the interaction of atoms of the substituting group with atoms of the main chain. The potential of this approach is demonstrated by the calculation of the melting points, heat capacities, entropies, and enthalpies and free energies of formation for 117 saturated hydrocarbon molecules, including all the linear C1-C20 molecules and branched C4-C10 molecules with methyl substituents; also the heats of vaporization are calculated for 72 molecules including all linear C1-C20 molecules and branched C4-C9 molecules with methyl substituents. The accuracy of all the estimates is high. When the linear contribution is taken into account more accurately, with correction for nonlinear variation of properties of linear molecules, it becomes possible to highly accurately in estimate various properties of both linear and branched molecules, using the molecular connectivity indices.

The structure-property correlation for linear molecules of the An type is represented by a simple function of n with a restricted number of parameters. The correlation is similar for all linear molecules with similar variations of all contributing values, so that related properties of any linear molecules vary similarly. This was exemplified by various physicochemical properties (boiling point, melting point, heat of sublimation, heat of vaporization, diamagnetic susceptibility, ionization potential, long-wave transition energy, hyperpolarizability, logarithm of the octanol-water distribution coefficient) for all saturated linear hydrocarbons and corresponding perfluoro derivatives, unsaturated linear hydrocarbons and those with conjugated double bonds, oligothiophenes, linearly fused aromatic rings, RNA duplexes, and bilayer lipide membranes. The simplified relations obtained allow a sufficiently precise assessment of various properties of any linear molecule.