Ivanovo State University of Chemistry and Technology

The paper considers the application of the RRHO and RRAO models (rigid rotor–harmonic oscillator and rigid rotor–anharmonic oscillator) to the calculations of thermodynamic functions ( H^∘ (T) - H^∘ (0) , Φ ^∘ (T) , etc.) of amino acids in the ideal gas state using valine as an example, taking into account internal hindered rotations. The dependence of thermodynamic functions on the number of conformers included in the ensemble is studied. It has been established that the RRHO approximation, when limited to only the main conformer, can be used to quickly estimate the high-temperature components of enthalpy when recalculating the enthalpy of sublimation, obtained according to the second law of thermodynamics, from the experimental temperature to 298.15 K. It has been shown that reliable determination of the enthalpy of sublimation according to the third law of thermodynamics with the least error requires very resource-intensive calculations according to the RRAO model taking into account internal rotations. A compromise option that provides an enthalpy error of 3–4

A series of new dicyano-containing dibenzo[b,f]imidazo[1,2-d][1,4]oxazepines was synthesized in 25–90

The capabilities of Knudsen effusion mass spectrometry in thermodynamic studies of chemical substances are demonstrated for four classes of compounds: porphyrins, spiropyrans, amino acids, and ionic liquids.

Thin crystalline films of a new complex Etioporphyrin-I silicon(IV) difluoride SiF2-EtioP-I were deposited by thermal vacuum evaporation. A distinct feature is an abnormal broadening of the Soret-band in the absorption spectrum of these films relative to the molecular form of the spectrum. For a 100 nm thick film the width (FWHMB) of this band exceeds 140 nm, which makes the porphyrin 'green gap' almost negligible. The spectral profile changes with a film thickness: the thinner the film, the narrower the absorption band. In similarly deposited films of their closest analogues, Etioporphyrin oxovanadium(IV) VO-EtioP-III (classical petroporphyrin) and VO-petroporphyrin mixture, the solid-state broadening of the Soret-band is smaller. Specific conductivity of the films decreases as follows: SiF2-EtioP-I > VO-EtioP-III > VO-PPs. We report fabricating and testing of thin-film solar cells with a single planar molecular D/A-junction, where a porphyrin donor is paired with a chlorinated subphthalocyanine acceptor (Cl(6)SubPc). SiF2-EtioP-I yields a better device performance than is achieved with its above analogues, due to a broader spectral activity and a higher efficiency of photon-to-electron conversion in the Soret-band range, accompanied by structuring of the D/A-interface. The power conversion efficiency of the cells employing SiF2-EtioP-I exceeds 5% under 1sun illumination and 14% when illuminated in the Soret-band range.

A new selective fluorescent probe based on a vitamin B6 derived hydrazone was synthesized and characterized for the detection of Al3+ and Ga3+ ions. The probe’s selectivity and sensitivity were evaluated using UV-Vis, fluorescence, and NMR spectroscopy in a buffered DMSO/water solution, complemented by density functional theory (DFT) calculations to elucidate the electronic structure and coordination modes of the resulting complexes. The probe exhibited a notable “turn-on” fluorescence response upon binding Al3+ and Ga3+, with emission maxima at 466 nm and 477 nm, respectively, and detection limits as low as 48 nM for Al3+ and 33 nM for Ga3+. The probe showed high selectivity for these ions over a wide range of competing cations and anions, forming stable 1:1 complexes with log β′ values of 5.98 for Al3+ and 6.28 for Ga3+. DFT calculations revealed a tridentate coordination mode via the phenolic oxygen, azomethine nitrogen, and carbonyl oxygen, with distinct electronic transitions for each complex, including a ligand-to-metal charge transfer character in the Ga3+ complex. The probe demonstrates reversibility and excellent solution stability, offering a simple and sensitive platform for the environmental and biological monitoring of aluminum(III) and gallium(III) ions.