Люминесценция дитолуоилметаната дифторида бора. Образование J-агрегатов

The processes of the formation of J-aggregates during the dissolution 2,2-difluoro-4,6-di(4’-methylphenyl)-1,3,2-dioxaborine crystals (1) and their subsequent dissociation have been studied by absorption and luminescence spectroscopy and quantum-chemical modeling. It is shown that two luminescent centers are observed in the solution 1: monomeric luminescence and luminescence of J-aggregates (dual luminescence). Evolution of absorption, luminescence excitation and luminescence spectra is observed over time, indicating a slow dissociation of J-aggregates.

Quantum Chemical Studies and Electrochemical Investigations of Polymerized Brilliant Blue-Modified Carbon Paste Electrode for In Vitro Sensing of Pharmaceutical Samples

To develop an electrochemical sensor for electroactive molecules, the choice and prediction of redox reactive sites of the modifier play a critical role in establishing the sensing mediating mechanism. Therefore, to understand the mediating mechanism of the modifier, we used advanced density functional theory (DFT)-based quantum chemical modeling. A carbon paste electrode (CPE) was modified with electropolymerization of brilliant blue, later employed for the detection of paracetamol (PA) and folic acid (FA). PA is an analgesic, anti-inflammatory and antipyretic prescription commonly used in medical fields, and overdose or prolonged use may harm the liver and kidney. The deficiency of FA associated with neural tube defects (NTDs) and therefore the quantification of FA are very essential to prevent the problems associated with congenital deformities of the spinal column, skull and brain of the fetus in pregnant women. Hence, an electrochemical sensor based on a polymerized brilliant blue-modified carbon paste working electrode (BRB/CPE) was fabricated for the quantification of PA and FA in physiological pH. The real analytical applicability of the proposed sensor was judged by employing it in analysis of a pharmaceutical sample, and good recovery results were obtained. The potential excipients do not have a significant contribution to the electro-oxidation of PA at BRB/CPE, which makes it a promising electrochemical sensing platform. The real analytical applicability of the proposed method is valid for pharmaceutical analysis in the presence of possible excipients. The prediction of redox reactive sites of the modifier by advanced quantum chemical modeling-based DFT may lay a new foundation for researchers to establish the modifier–analyte interaction mechanisms.

Reactions of Malononitrile Dimer with Isothiocyanates

The reaction of 2-amino-1,1,3-tricyanopropene (malononitrile dimer) with isothiocyanates leads to 1-substituted 4,6-diamino-2-thioxo-1,2-dihydropyridine-3,5-dicarbonitriles or 4,6-diamino-2-(phenylimino)-2H-thiopyran-3,5-dicarbonitrile, depending on the conditions. Quantum-chemical modeling of the IR spectra and reaction routes for the synthesized compounds was carried out. In silico predictive analysis of potential protein targets, compliance with bioavailability criteria, and ADMET parameters was performed.

Quantum-chemical modeling of the processes of cadmium sulfide and cadmium selenide films synthesis in aqueous solutions

The quantum-chemical modeling of the synthesis process chemistry of CdS and CdSe in aqueos solutions was carried out. For that reason, the CdS synthesis simulation was carried out through the formation of Cd(II) complex forms with the trisodium citrate and ammonium hydroxide. At the CdSe synthesis, the sodium selenosulfate with and without trisodium citrate was used. It was established that this process passes through several intermediate stages with the transitional reactive complexes formation. On the basis of obtained data, the energy stages diagrams are constructed and the comparison of CdS and CdSe synthesis processes with various complexing agents has been carried out. The CdS and CdSe films were obtained by chemical synthesis method from an aqueous solution of cadmium salt, complexing and chalcogenizing agents. X-ray phase analysis confirmed the formation of desired compounds, which was predicted by modeling.