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Archive for 30.11.2017

Tetrahedron, 2017, 73, 3939–3948

A.N. Shestakov, A.S. Pankova, P. Golubev, A.F. Khlebnikov, M.A. Kuznetsov

“Brønsted acid mediated cyclizations of ortho-aryl(ethynyl)pyrimidines”

Tetrahedron, 2017, 73 (27-28), 3939–3948
DOI: 10.1016/j.tet.2017.05.070

source: http://www.sciencedirect.com/science/article/pii/S0040402017305719

A high-yielding procedure for the synthesis of 5-aryl-4-(arylethynyl)pyrimidines from easily available 2-aryl-3-hydroxyacrylates is reported. These pyrimidines readily undergo cyclization in strong Brønsted acids and, depending on the substitution in alkynylpyrimidines and the water content of the reaction mixture, yield either benzo[f]quinazolines or derivatives of spiro[cyclohexa-2,5-diene-1,5′-cyclopenta[d]pyrimidin]-4-one. In most cases the cyclization proceeds nearly quantitatively. DFT calculations support the proposed mechanisms induced by the protonation of the triple bond in 5-aryl-4-(arylethynyl)pyrimidines. Fluorescent properties of the obtained heterocycles are also described.

Экскурсия


Обзорная экскурсия-лекция для студентов физического факультета СПбГУ. В ходе экскурсии студенты посетили лаборатории ЯКР, ЯМР, ЭПР и познакомились с некоторыми особенностями и возможностями оборудования, представленного в рц МРМИ.

Стажировка


В ходе стажировки 18-26 ноября Мазур А.С. успешно освоил методы проведения низкотемпературных измерений спектров ЯМР в широком частотном диапазоне (250 – 500 МГц) на оборудовании представленном в Отделении низкотемпературной физики факультета математики и физики Карлова университета в Праге.

Dalton Transactions, 2017, 46, 3895-3905

A.I. Solomatina, I.O. Aleksandrova, A.J. Karttunen, S.P. Tunik, I.O. Koshevoy

“Dibenzothiophene-platinated complexes: probing the effect of ancillary ligands on the photophysical performance”

Dalton Transactions, 2017, 46, 3895-3905
DOI: 10.1039/C7DT00349H

source: http://pubs.rsc.org/en/Content/ArticleLanding/2017/DT/C7DT00349H#!divAbstract

Cyclometalation of dibenzothienyl-pyridine (HPyDBT) afforded a series of platinum(II) complexes Pt(PyDBT)(L)Cl (L = DMSO, 1; P(p-C6H4-X)3 (X = H, 2; CF3, 3; OMe, 4; NPh2, 5); 1,3,5-triaza-7-phosphaadamantane, 6; 2,6-dimethylphenyl isocyanide, 7). Chelating bidentate LL ligands formed cationic compounds [Pt(PyDBT)(LL)]+ (LL = 1,2-bis(diphenylphosphino)benzene, 8; 2,2′-bipyridine, 9; 1,10-phenanthroline, 10). Oxidation of a thienyl sulfur atom allowed for the isolation of the sulfone derivative Pt(PyDBT)(PPh3)Cl (11). The title complexes were characterized crystallographically (except 7). Investigation of their photophysical behavior revealed solid state phosphorescence with quantum yields up to 0.45 for neat powders. The ancillary ligands L show a minor influence on the emission energies of the neutral compounds, but affect dramatically the intensity of luminescence. In contrast, the cationic species with diimine ligands demonstrate a significant contribution of the LL fragments into the emissive T1 states that leads to a certain mixing of 3IL and 3LL′CT transitions and causes a substantial bathochromic shift of emission.

Журнал органической химии, 2017, 53(11), 1726-1728

О.М. Нестерова, О.С. Зарубина, В.В. Толстяков, Г.Г. Данагулян, Р.Е. Трифонов, С.Н. Смирнов, П.А. Слепухин, Н.К. Игнатенко, В.А. Островский

“Синтез и строение N-(4,6-диметилпиримидин-2-ил)-2-(5-фенил-2Н-тетразол-2-ил)ацетогидразида и 1-(4,6-диметилпиримидин-2-ил)-3-[(5-фенил-2Н-тетразол-2-ил)метил]-1Н-пиразол-5-ола”

Журнал органической химии, 2017, 53(11), 1726-1728

Синтезированы новые тетразолильные производные 4,6-диметилгидразина, содержащие различные линкерные группы. Определена структура данных соединений методами ЯМР спектроскопии
и рентгеноструктурного анализа

Scientific Reports, 2017, 7, 41991

E. G. Vlakh, E. V. Grachova, D. D. Zhukovsky, A. V. Hubina, A. S. Mikhailova, J. R. Shakirova, V. V. Sharoyko, S. P. Tunik, T. B. Tennikova

“Self-assemble nanoparticles based on polypeptides containing C-terminal luminescent Pt-cysteine complex”

Scientific Reports, 2017, 7, Article number 41991
DOI: 10.1038/srep41991

source: https://www.nature.com/articles/srep41991

The growing attention to the luminescent nanocarriers is strongly stimulated by their potential application as drug delivery systems and by the necessity to monitor their distribution in cells and tissues. In this communication we report on the synthesis of amphiphilic polypeptides bearing C-terminal phosphorescent label together with preparation of nanoparticles using the polypeptides obtained. The approach suggested is based on a unique and highly technological process where the new phosphorescent Pt-cysteine complex serves as initiator of the ring-opening polymerization of α-amino acid N-carboxyanhydrides to obtain the polypeptides bearing intact the platinum chromophore covalently bound to the polymer chain. It was established that the luminescent label retains unchanged its emission characteristics not only in the polypeptides but also in more complicated nanoaggregates such as the polymer derived amphiphilic block-copolymers and self-assembled nanoparticles. The phosphorescent nanoparticles display no cytotoxicity and hemolytic activity in the tested range of concentrations and easily internalize into living cells that makes possible in vivo cell visualization, including prospective application in time resolved imaging and drug delivery monitoring.

Carbohydrate Polymers, 2017, 169, 117–126

N.G. Voron’ko, S.R. Derkach, M.A. Vovk, P.M. Tolstoy

“Complexation of κ-carrageenan with gelatin in the aqueous phase analysed by 1H NMR kinetics and relaxation”

Carbohydrate Polymers, 2017, 169, 117–126
DOI: 10.1016/j.carbpol.2017.04.010

The 1H NMR spectroscopy is used to study the kinetics of gelation in the aqueous mixtures of κ-carrageenan with gelatin. The time dependence of NMR signals intensities shows that the kinetics of gel formation consists of classical ‘fast’ (rate constant k ≈ 6 h−1) and ‘slow’ (k ≈ 1 h−1) periods, corresponding to a coil → helix transition and subsequent aggregation of helices. Upon increase of the κ-carrageenan/gelatin (w/w) ratio Z the rate of the fast process slows down by a factor of 1.6–2.4. Further analysis was done by studying the dependence of spin-spin relaxation times of protons of gelatin on Z in the aqueous phase. A qualitative scheme describing hydrogel formation in the complex solution is given. It is hypothesized that at higher concentration of PECs the hydrogel structure network is stabilized by three types of nodes: triple helices of gelatin and intra-/inter-molecular double helices of κ-carrageenan.

Октябрь

В Октябре выполнено 2347 заявок на сервисные измерения.

Измерено:

  • 2218 спектр 1H
  • 366 спектра 13C
  • 95 спектров DEPT
  • 63 спектров COSY
  • 19 спектра NOESY
  • 52 спектра 31Р
  • 169 спектров 19F

Выполнено 242 заявок на исследовательскую работу.