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Vol 522, No 1 (2025)
CHEMISTRY
Structural Diversity and Luminescent Properties of Lanthanide Coordination Polymers with 4,7-Di(4-Carboxypyrazole-1-Yl)-2,1,3-Benzoxadiazole
Abstract
A series of new lanthanide metal-organic coordination polymers with 4,7-di(4-carboxypyrazol-1-yl)-2,1,3-benz- oxadiazole were synthesized. It was established that, depending on the position of element in the lanthanide series, products of four structural types are formed. In the case of the Ce3+ cation, the coordination polymer represents 1D chains, for Pr3+–Er3+ cations it is a 2D layered structure with layer concatenation, and for the late lanthanides Tm3+–Lu3+ two types of layered coordination polymers were identified, differing in the carboxylate group coordination mode and the number of coordinated water molecules in the coordination sphere of the central ion. The coordination polymers of Sm3+, Eu3+, Gd3+, and Tb3+ exhibit only ligand-centered luminescence with a maximum in the range of 540–550 nm, while the luminescence spectrum of Nd3+ coordination polymer additionally contains characteristic bands of metal-centered emission in the near infrared range at 878, 1054, 1330, and 1568 nm.
Doklady Chemistry. 2025;522(1):3-13
3-13
Features of the Structure of 2,5-Dimercapto-1,3,4-Thiadiazole
Abstract
For the first time, using quantum chemical analysis, the structure of 2,5-dimercapto-1,3,4-thiadiazole was proposed, which is described by a single formula in the form of three putative isomers, which is a crystalline tribasic RS–H Brensted acid formed solely by hydrogen bonds involving four nitrogen atoms and three sulfur atoms, which is confirmed by X-ray diffraction analysis and FTIR spectra. These structural features must be considered in the production technology of the target product.
Doklady Chemistry. 2025;522(1):14-18
14-18
Synthesis and evaluation of the proteolytic stability of вос-trp-pro-pro-trp and trp-pro-pro-trp of peptide analogues of pam-43 of allosteric modulator of ampa receptors
Abstract
Peptides Вос-Trp-Pro-Pro-Trp and Trp-Pro-Pro-Trp were synthesized, structurally similar to PAM-43, which is a positive allosteric modulator (PAM) of AMPA receptors, the malfunction of which is considered as a symptom of many pathologies. The use of peptides synthesized from amino acids of a natural structure, unlike chemical compounds foreign to the body, as a rule, have low cytotoxicity, which allows their use in the necessary doses. It was shown that the most successful way to obtain Вос-Trp-Pro-Pro-Trp and Trp-Pro-Pro-Trp was to start synthesis by obtaining Pro-Pro, which was condensed with Вос-Trp and Trp. Their resistance to the action of peptidases has been determined. It turned out that the main way of degradation of peptides is the cleavage of the C-terminal bond of Pro-Trp with the formation of corresponding metabolites, which also degrade due to the cleavage of peptide bonds from the C-terminus of the molecule. Further studies of these peptides will make it possible to consider them as possible candidates for a new direction in the search for effective peptide analogues of PAM, with the aim of creating medicines based on them in the future.
Doklady Chemistry. 2025;522(1):19-28
19-28
PHYSICAL CHEMISTRY
Photooxidation of bis-thiacarbocyanine dyes and their supramolecular complexes with cucurbit[8]uril by viologens
Abstract
The photooxidation reaction of bis-thiacarbocyanines based on 3,3'-dimethylthiacarbocyanine by viologens (methyl viologen, p-chlorophenyl viologen, p-cyanophenyl viologen) in acetonitrile, as well as their complexes with cucurbit[8]uril by monomeric complexes of viologens with cucurbit[8]uril in water was studied. The result of the photooxidation reaction of dye monomers in acetonitrile is the formation of the thiacarbocyanine dication-radical, bis-thiacarbocyanine trication-radicals and viologen cation-radicals. The consequence of photooxidation in water in the presence of cucurbit[8]uril is the formation of trication radicals of dye complexes and cation radicals of viologen complexes.
Doklady Chemistry. 2025;522(1):29-34
29-34
Photoinduced Electron Transfer in Reactions of 6-Oxofascaplysine with Biomolecules Studied by the Chemically Induced Dynamic Nuclear Polarization
Abstract
A new approach for the synthesis of the anticancer agent 6-oxofascaplysine has been developed and its photochemical activity has been studied for the first time using the method of chemically induced dynamic nuclear polarization. It was found that 6-oxofascaplysine in triplet excited state enters into electron transfer reaction with biomolecules – aromatic amino acids (tryptophan and tyrosine) and 1,4-dihydropyridine (NADH analogue), as well as into energy transfer reaction with oxygen molecule with formation of singlet oxygen. The structure of the radical intermediate of 6-oxofascaplysine has been established. These data may be useful for evaluating the prospects for the use of 6-oxofascaplysine in photodynamic therapy.
Doklady Chemistry. 2025;522(1):35-41
35-41
Magnetosensitive luminescence of recombination exciplexes of dimethyl and dimethoxy tolan with N,N-dimethylaniline generated by X-irradiation in nonpolar solution
Abstract
On the example of three compounds it is demonstrated that upon X-irradiation in nonpolar solution donor- substituted dimethyl- and dimethoxy-(diphenylacetylenes) form exciplexes with N,N-dimethylaniline via recombination of the respective radical ions with an intense magnetosensitive band of luminescence. Exciplexes of dimethyldiphenylacetylenes have the highest light production of all recombination exciplexes of diphenylacetylenes known so far. The studied compounds and their analogs as a class may be considered as potential blue emitters for organic electroluminescent systems, including magnetosensitive ones.
Doklady Chemistry. 2025;522(1):42-50
42-50
THE X-RAY PHOTOELECTRON SPECTROSCOPY IN THE ATMOSPHERE OF HIGHLY PURE NOBLE GASES
Abstract
A variant of the X-ray photoelectron spectroscopy method is disclosed. To clean the surface of the sample under study, the spectrum is recorded under continuously ventilation the working chamber of spectrometer with installed sample with a extra-pure noble gas at 10–3–10–1 Pa. It is shown that the proposed approach allows to obtain representative spectra of the sample surface free of adsorbed particles, contaminants and impurities without using ultra-high vacuum technology and without destructive effects on the sample surface. The proposed approach ensures a relatively quick preparation of the device for operation, as well as the possibility of studying samples that are destroyed under ultra-high vacuum conditions (crystal hydrates, organic compounds) and under the influence of hard methods of surface cleaning, such as mechanical cleaning, significant heating or ion etching.
Doklady Chemistry. 2025;522(1):51-56
51-56