English

Molecules, 2016, 21, 1657-1/19

L. Sobczyk, D. Chudoba, P.M. Tolstoy, A. Filarowski

“Some Brief Notes on Theoretical and Experimental Investigations of Intramolecular Hydrogen Bonding”

Molecules, 2016, 21, 1657-1/19
DOI:10.3390/molecules21121657

A review of selected literature data related to intramolecular hydrogen bonding in ortho-hydroxyaryl Schiff bases, ortho-hydroxyaryl ketones, ortho-hydroxyaryl amides, proton sponges and ortho-hydroxyaryl Mannich bases is presented. The paper reports on the application of experimental spectroscopic measurements (IR and NMR) and quantum-mechanical calculations for investigations of the proton transfer processes, the potential energy curves, tautomeric equilibrium, aromaticity etc. Finally, the equilibrium between the intra- and inter-molecular hydrogen bonds in amides is discussed.

 

Phys. Chem. Chem. Phys., 2016, accepted

B. Koeppe, S.A. Pylaeva, C. Allolio, D. Sebastiani, E.T.J. Nibbering, G.S. Denisov, H.-H. Limbach, P.M. Tolstoy

“Polar solvent fluctuations drive proton transfer in hydrogen bonded complexes of carboxylic acid with pyridines: NMR, IR and ab initio MD study”

Phys. Chem. Chem. Phys., 2016, accepted
DOI:10.1039/C6CP06677A

koeppe

We study a series of intermolecular hydrogen-bonded 1 : 1 complexes formed by chloroacetic acid with 19 substituted pyridines and one aliphatic amine dissolved in CD2Cl2 at low temperature by 1H and 13C NMR and FTIR spectroscopy. The hydrogen bond geometries in these complexes vary from molecular (O–H…N) to zwitterionic (O…H–N+) ones, while NMR spectra show the formation of short strong hydrogen bonds in intermediate cases. Analysis of CQO stretching and asymmetric CO2 stretching bands in FTIR spectra
reveal the presence of proton tautomerism. On the basis of these data, we construct the overall proton transfer pathway. In addition to that, we also study by use of ab initio molecular dynamics the complex formed by chloroacetic acid with 2-methylpyridine, surrounded by 71 CD2Cl2 molecules, revealing a dualmaximum distribution of hydrogen bond geometries in solution. The analysis of the calculated trajectory shows that the proton jumps between molecular and zwitterionic forms are indeed driven by dipole–dipole solvent–solute interactions, but the primary cause of the jumps is the formation/breaking of weak CH…O bonds from solvent molecules to oxygen atoms of the carboxylate group.

 

Ноябрь

В ноябре выполнено 1963 заявки на сервисные измерения.

Измерено:

  • 1883 спектра 1H
  • 329 спектров 13C
  • 144 спектра DEPT
  • 31 спектр COSY
  • 13 спектров NOESY
  • 107 спектров 31Р
  • 54 спектра 19F

Выполнено 206 заявок на исследовательскую работу.

J. Org. Chem., 2016, 81, 11268-11275

P. Golubev, E.A. Karpova, A.S. Pankova, M. Sorokina, M.A. Kuznetsov

“Regioselective Synthesis of 7‑(Trimethylsilylethynyl) pyrazolo [1,5‑a] pyrimidines via Reaction of Pyrazolamines with Enynones”

J. Org. Chem., 2016, 81, 11268-11275
DOI:10.1021/acs.joc.6b02217

Condensation of enynones readily available from cheap starting material with pyrazolamines provides easy access to fluorescent 7-(trimethylsilylethynyl)pyrazolo[1,5-a]pyrimidines. The reaction is straightforward, does not require the use of any additional reagents or catalysts, and can be performed without inert atmosphere. Various substituents and functional groups in both enynone and pyrazolamine are tolerated. The presented method features full regioselectivity, high isolated yields, and simplicity of both setup and product purification. Fluorescent properties of the obtained pyrazolopyrimidines were studied.

 

Beilstein J. Org. Chem., 2016, 12, 2563-2569

A.S. Pankova, P.R. Golubev, A.F. Khlebnikov, A.Yu. Ivanov, M.A. Kuznetsov

“Thiazol-4-one derivatives from the reaction of monosubstituted thioureas with maleimides: structures and factors determining the selectivity and tautomeric equilibrium in solution”

Beilstein J. Org. Chem., 2016, 12, 2563-2569
DOI:10.3762/bjoc.12.251

2-(Alkyl(aryl)amino)thiazol-4(5H)-ones can regioselectively be prepared from monoalkyl(aryl)thioureas and maleimides. In solution, the former heterocycles exist in a tautomeric equilibrium with 2-(alkyl(aryl)imino)thiazolidin-4-ones and the substituent on the exocyclic nitrogen atom governs the ratio of these tautomers. Isomers with the alkyl group in the endocyclic position can be obtained from N-methyl(ethyl)thioureas. 2D NMR spectroscopy and DFT calculations rationalize experimental results.

 

New J. Chem., 2016, 40, 10028-10040

A.V. Artem’ev, E.P. Doronina, M.I. Rakhmanova, A.O. Sutyrina, I.Yu. Bagryanskaya, P.M. Tolstoy, A.L. Gushchin, A.S. Mazur, N.K. Gusarova, B.A. Trofimov

“Luminescent CuI thiocyanate complexes based on tris(2-pyridyl)phosphine and its oxide: from mono-, di- and trinuclear species to coordination polymer”

New J. Chem., 2016, 40, 10028-10040
DOI:10.1039/C6NJ02087A

43_artemev

Tris(2-pyridyl)phosphine oxide reacts with CuSCN to form a variety of luminescent complexes, depending on the specified metal-to-ligand ratio and the solvent used, viz. mononuclear [Cu(N,N′,N′′-Py3P=O)(NCS)], dinuclear (N,N′-Py3P=O)Cu(SCN NCS)Cu[(N,N′-Py3P=O)], their co-crystal (2 : 1, correspondingly) and trinuclear {Cu(NCS)[SCNCu(N,N′,N′′-Py3P=O)]2}. In the solid state, these complexes feature red-orange emission upon UV photoexcitation. The reaction of tris(2-pyridyl)phosphine with CuSCN quantitatively produces an almost insoluble coordination polymer, [Cu(Py3P)NCS]n, which exhibits bright green emission. The synthesized compounds are the first members of the hitherto unknown family of Cu(I) thiocyanate complexes supported by tripodal ligands.

 

Экскурсия

20161128_122333212
Обзорная экскурсия для студентов-бакалавров 4 курса химического факультета. П.М. Толстой провел вводную лекцию для наших посетителей, М.А. Вовк, А.С. Мазур, С.М. Сухаржевский провели демонстрацию ЯМР, ЯКР и ЭПР спектрометров.

Tetrahedron Lett., 2016, 57, 5192-5196

M.N. Putintseva, O.Yu. Bakulina, A.Yu. Ivanov, P.S. Lobanov, S.K. Nikolskaya, I.E. Kolesnikov, D.V. Dar’in

“Double tandem cyclization of 4-(1-acyl-2,2-diaminovinyl)-6-arylpyrimidine-5-carbonitriles. Synthesis of novel peri-annulated azines”

Tetrahedron Lett., 2016, 57, 5192-5196
DOI:10.1016/j.tetlet.2016.10.020

A series of novel peri-fused azines, pyrimido[4,5,6-de]quinolino[2,3-b][1,8]naphthyridines and benzo[b]pyrimido[4,5,6-de][1,8]naphthyridines, were prepared via the base-promoted double tandem cyclization of 4-(1-acyl-2,2-diaminovinyl)-6-(haloaryl)pyrimidine-5-carbonitriles. This transformation represents a rare example of the one-pot synthesis of peri-annulated polycyclic structures from non-fused heterocycles. The synthesized pyrimido[4,5,6-de]quinolino[2,3-b][1,8]naphthyridines were found to be luminophores.

Семинар


Д-р Константинос Сотириадис, институт теоретической и прикладной механики, Академия наук Чехии представил доклад о своей научной деятельности и работе, проделанной в РЦ МРМИ.

Spinus-2016


Сегодня РЦ МРМИ посетили участники зимней школы-конференции Spinus-2016. Для гостей РЦ проведена обзорная экскурсия, в рамках которой представлено современное оборудование, применяемое в областях спектроскопии ЯМР, ЭПР, ЯКР. В ходе экскурсии приведены примеры некоторых экспериментальных задач, решаемых в РЦ МРМИ. В понедельник, 21.11.16, П. М. Толстой прочел участникам конференции Spinus-2016 лекцию «Изучение кооперативности водородных связей методами жидкостной спектроскопии ЯМР».