0000000000033719
AUTHOR
Oleg V. Shishkin
showing 12 related works from this author
Columnar supramolecular architecture of crystals of 2-(4-Iodophenyl)-1,10-phenanthroline derived from values of intermolecular interaction energy
2011
Using results of X-ray diffraction study supramolecular architecture of crystals of 2-(4-iodophenyl)-1,10-phenanthroline has been analyzed on the basis of quantum-chemical calculations of intermolecular interactions energy. It is demonstrated that these crystals have three levels of organization. Molecules form stacked dimers with the highest binding energy (first level). These dimers represent basic unit of infinite columns stabilized by stacking interactions between dimers (second level). The energy of intermolecular interactions between neighbouring stacked columns is very close. This does not allow to figure out any layers in the crystal. Therefore crystals of this compound have columna…
Synthesis and Tautomerization of 6,7-Dihydro-(1,2,3)-triazolo[1,5-a]pyrimidines.
2007
The condensation of 5-amino-4-phenyl-1,2,3-triazole (1) with chalcones 2a-e or 3-dimethylamino-propiophenone (4f) leads to the 6,7-dihydro-(1,2,3)-triazolo[1,5-a]pyrimidines 3a-f. The equilibrium of 3 and the tautomeric 4,7-dihydro-(1,2,3)-triazolo[1,5-a]pyrimidines 3′ is described.
Tautomerism of Diazepines Fused with Pyrimidine Rings.
2003
The tautomerism of 1,4-diazepines fused with pyrimidine rings was studied by means of nmr spec-troscopy, X-ray analysis and quantum chemical calculations. It was found that in the case of 6,8-diphenyl-pyrimido[4,5-b][1,4]diazepin-4-ols (7a - e) the enamine form is more stable than the diimine form. This result is rationalized with the electron-withdrawing effect of the 4-hydroxypyrimidine ring and with the formation of intermolecular hydrogen bonds. In contrast to 7a - e, the 6,8-diaryl-2,3,4,7-tetrahydro-1,3-dimethyl-1H-pyrimido[4,5-b][1,4]diazepine-2,4-diones (9a, c, f) exist in the diimine form.
Reactions of 4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidines with α,β-unsaturated carbonyl compounds
2004
The reaction of 5,7-diphenyl-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine (1) with α,β-unsaturated carbonyl compounds 2a-f led to the formation of the alkylated heterocycles 3a-f (Figure 1). However, the reaction of 5-methyl-7-phenyl-4,7-dihydro-1,2,4-triazolo[1,5-a]pyrimidine (5) with 2a-c yielded under the same conditions the triazolo[5,1-b]quinazolines 6a-c (Figure 3). In this case, the alkylation is followed by a cyclocondensation. The structure elucidation of the products is based on ir, ms, 1H and 13C nmr measurements and on an X-ray diffraction study.
Supramolecular diversity and magnetic properties of novel heterometallic Cu(II)/Cr(III) complexes prepared from copper powder, Reineckes salt and eth…
2009
Abstract Three novel heterometallic complexes [Cu(en) 2 Cr(NCS) 4 (NH 3 ) 2 ][Cr(NCS) 4 (NH 3 ) 2 ] · 6dmf ( 1 ), [Cu(en) 2 Cr(NCS) 4 (NH 3 ) 2 ](OAc) ( 2 ) and [{Cu(en) 2 } 3 {Cr(NCS) 4 (NH 3 ) 2 } 2 (NCS) 2 ](NCS) 2 ( 3 ) have been synthesized in a one-pot reaction from copper powder, Reineckes salt, NH 4 X [X − = OAc − ( 2 ), NCS − ( 3 )] in a dmf ( 1 ) or CH 3 CN ( 2 , 3 ) solution of ethylenediamine (en). X-ray studies showed that 1 and 2 consist of cationic polymeric chains, formed by Cu ( en ) 2 2 + and Cr ( NCS ) 4 ( NH 3 ) 2 - building blocks that bridged through thiocyanate anions. In both complexes, distinct hydrogen bonds are present and serve to increase the dimensionality of …
Structural and magnetic studies of tetranuclear heterometallic M/Cr (M = Co, Mn) complexes self-assembled from zerovalent cobalt or manganese, Reinec…
2010
Abstract Four novel heterometallic complexes [Co2Cr2(NCS)4(HDea)2(Dea)2]·4dmf (1), [Co2Cr2(NCS)4(HDea)2(Dea)2]·4dmso (2), [Mn2Cr2(NCS)4(HDea)2(Dea)2(dmf)2]·2dmf (3) and [Mn2Cr2(NCS)4(HDea)2(Dea)2(dmso)2]·4dmso (4) have been prepared using zerovalent cobalt (1, 2) or manganese (3, 4), Reineckes salt, ammonium thiocyanate and a non-aqueous solution of diethanolamine (H2Dea) in air. The single X-ray analysis reveals that all compounds have similar centrosymmetric crystal structures based on a tetranuclear {M2Cr2(μ3-O)2(μ-O)4} (M = Co, Mn) core. Variable-temperature magnetic susceptibility measurements of 1, 2 and 4 show antiferromagnetic coupling between the magnetic centers, while 3 exhibits …
Cyclecondensation of 3-amino-1,2,4-triazole with substituted methyl cinnamates
1999
The reaction of 3-amino-1,2,4-triazole (1) with substituted methyl cinnamates 2a-h leads selectively to the formation of 7-aryl-6,7-dihydro[1,2,4]triazolo[1,5-a]pyrimidin-5(4H)-ones 3a-h. The structure eluci dation of the products is based on ir, 1H and 13C nmr measurements and X-ray diffraction.
OH–π and halogen–π interactions as driving forces in the crystal organisations of tri-bromo and tri-iodo trityl alcohols
2008
The trityl alcohols bearing three bromine or three iodine atoms at the para-positions of the aromatic units, have been known for more than a hundred years. In our case these compounds have been synthesized in one-pot sequence starting from the 1,4-dihalogenobenzenes via mono-lithiation and the successive reaction with diethylcarbonate. The compounds have been crystallized from different solvent mixtures leading to one structure of bromo- (A) and three structures of iodo trityl alcohols (B–D). The inclusion of dichloromethane (C) or benzene (D) in the crystalline lattices has been observed. In all cases the OH–π and halogen–π (and in one case the halogen-halogen and CH-O weak) contacts play …
CCDC 998788: Experimental Crystal Structure Determination
2014
Related Article: Roman I. Zubatyuk, Anna A. Sinelshchikova, Yulia Y. Enakieva, Yulia G. Gorbunova, Aslan Y. Tsivadze, Sergey E. Nefedov, Alla Bessmertnykh-Lemeune, Roger Guilard, Oleg V. Shishkin|2014|CrystEngComm|16|10428|doi:10.1039/C4CE01623H
CCDC 998789: Experimental Crystal Structure Determination
2014
Related Article: Roman I. Zubatyuk, Anna A. Sinelshchikova, Yulia Y. Enakieva, Yulia G. Gorbunova, Aslan Y. Tsivadze, Sergey E. Nefedov, Alla Bessmertnykh-Lemeune, Roger Guilard, Oleg V. Shishkin|2014|CrystEngComm|16|10428|doi:10.1039/C4CE01623H
CCDC 998787: Experimental Crystal Structure Determination
2014
Related Article: Roman I. Zubatyuk, Anna A. Sinelshchikova, Yulia Y. Enakieva, Yulia G. Gorbunova, Aslan Y. Tsivadze, Sergey E. Nefedov, Alla Bessmertnykh-Lemeune, Roger Guilard, Oleg V. Shishkin|2014|CrystEngComm|16|10428|doi:10.1039/C4CE01623H
CCDC 998790: Experimental Crystal Structure Determination
2014
Related Article: Roman I. Zubatyuk, Anna A. Sinelshchikova, Yulia Y. Enakieva, Yulia G. Gorbunova, Aslan Y. Tsivadze, Sergey E. Nefedov, Alla Bessmertnykh-Lemeune, Roger Guilard, Oleg V. Shishkin|2014|CrystEngComm|16|10428|doi:10.1039/C4CE01623H