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71.
We use quantum-chemical density functional theory calculations to elucidate the origin of spin-crossover pathways in two iron(II) [2×2] molecular grids with carbohydrazide-based bridging ligands. The complexes are characterized energetically and structurally in five available spin states. Special attention is paid to analysis of the structural distortion induced on each iron center by spin transition on any of its neighbors. The evolution of coordination polyhedra is monitored using the Continuous Shape Measures. It is demonstrated that a succession of spin transitions on different centers depends on the character of the induced distortion, either approaching or getting them away from a more regular low-spin geometry. These effects, resulting from the elasticity of bridging ligands, can be modulated by weak perturbations such as a change of the positions of the hydrogen atoms. 相似文献
72.
Andrei V. Churakov Sergey S. Karlov Elmira Kh. Lermontova Galina S. Zaitseva Judith A. K. Howard 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(12):o761-o762
The title compound, C24H17F10N3O2, exhibits intramolecular N—H...O hydrogen bonding, as well as intramolecular Ar...ArF face‐to‐face interactions. The molecules are linked together by N—H...F—C hydrogen bonds, forming chains parallel to the a axis. Adjacent symmetry‐related chains are combined in double zipper‐like ribbons by parallel ArF...ArF offset π‐stacking interactions. 相似文献
73.
Epoxidation of various alkenes in low to high yields (29-100%) and good to excellent selectivities (75-100%) was performed with tetrabutylammonium monopersulfate in the presence of meso-tetrakis(pentafluorophenyl)porphyrin as catalyst and tetrabutylammonium acetate or fluoride or imidazole as co-catalysts in CH2Cl2, in less than 10 min at room temperature (∼25 °C). 相似文献
74.
Samvel N. Sirakanyan Athina Geronikaki Viktor G. Kartsev Elmira K. Hakobyan Anush A. Hovakimyan 《合成通讯》2019,49(10):1262-1276
Taking into account previously obtained biological results on some polyheterocyclic compounds (containing different heteroatoms) and in particular on several 8-amino-5-isopropyl-2,2-dimethyl-10-(methylthio)-1,4-dihydro-2H-pyrano[4’’,3’’:4’,5’]pyrido[3’,2’:4,5]thieno[3,2-d]pyrimidines Ia-v we have carried out the synthesis of twentyone 8-amino-5-isobutyl-2,2-dimethyl-10-(methylthio)-1,4-dihydro-2H-pyrano[4’’,3’’:4’,5’]pyrido[3’,2’:4,5]thieno[3,2-d]pyrimidines 6. Therefore we have slightly modified the structure of the previously studied I introducing at C-5 an isobutyl group instead of the previously examined isopropyl ones in order to see if this variation (changing a little the lipophilicity) will affect the biological activity. Furthermore thieno[3,2-d]pyrimidine-8-thione 7 and their S-alkylated 8 were synthesized. Finally by alkylation of 5-isobutyl-2,2-dimethyl-10-thioxo-1,4,10,11-tetrahydro-2H-pyrano[4'',3'':4',5']pyrido[3',2':4,5]thieno[3,2-d]pyrimidin-8(9H)-one 3 with alkyl dichlorides (bifunctional reagents) we realized the cyclization of a thiazole or thiazine ring on the [b] side of the pyrimidine ring with formation of the new condensed pentaheterocyclic systems: pyrano[4'',3'':4',5']pyrido[3',2':4,5]thieno[3,2-d][1,3]thiazolo[3,2-a]pyrimidin-8-one 11 and pyrano[4''',3''':4'',5'']pyrido[3'',2'':4',5']thieno[3',2':4,5]pyrimido[2,1-b][1,3]thiazin-8-one 12. It was found that some of the synthesized compounds showed interesting antimicrobial activity (by agar diffusion method) against some gram-positive and gram-negative bacilli strains. 相似文献
75.
Elmira M. Gibadullina Albert R. Kayupov Yulia K. Voronina Victor V. Syakaev Michael A. Pudovik Alexander R. Burilov 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):787-795
AbstractPhosphorylation of 1,3-bis(2-hydroxyethoxy)benzene and octa(2-hydroxyethyl) calix[4]-resorcinarenes with P(III) acid amides and chloramides has been studied. It has been determined that the nature of phosphorous acid amides affects significantly the synthetic result of the reaction. 相似文献
76.
Badma N. Mankaev Valeriia A. Serova Dr. Mikhail A. Syroeshkin Anna Ya. Akyeva Dr. Alexey V. Sobolev Dr. Andrei V. Churakov Dr. Elmira Kh. Lermontova Dr. Mikhail E. Minyaev Dr. Yury F. Oprunenko Dr. Maxim V. Zabalov Kirill V. Zaitsev Dr. Galina S. Zaitseva Prof. Dr. Sergey S. Karlov 《欧洲无机化学杂志》2023,26(11):e202200690
A series of novel tetrylenes based on three 2,6-bis(2-hydroxyphenyl)pyridines 4 a – 4 c have been obtained by the reaction of Lappert's tetrylenes E[N(SiMe3)2]2 (E=Ge, Sn) with corresponding tridentate pyridine-linked phenol-based ligands. It was found that the structure of the ligand and the size of the atom of the group 14 element drastically affect the structure of the reaction product. Ligand 4 c with a bulky tert-butyl group leads to monomeric tetrylenes, while ligands with less bulky groups lead to bis-ligand derivatives of M(IV) (M=Ge, Sn) and a coordination polymer. Also, derivatives of germanium (IV) and tin (IV) were obtained by the metathesis reaction of MCl4 (M=Ge, Sn) with lithium phenoxides. The compositions and structures of the novel compounds were established by elemental analysis and 1H, 13C, 119Sn ( 5 – 7 ), 1H DOSY ( 6 ) NMR spectroscopy, in the solid state by X-ray diffraction analysis (germylene 10 , stannylene 6 , Ge4+ compound 8 , Sn4+ compound 7 ) and 119Sn Mössbauer spectrum of tin complex 6 . All the synthesized tetrylenes are monomeric. Tetrylenes 6 and 10 were characterized by cyclic voltammetry. A study of the redox behavior of 6 , 10 by cyclic voltammetry on a glassy carbon working electrode in acetonitrile solution of 0.1 M Bu4NPF6 as a supporting electrolyte showed that these compounds can be both oxidized and reduced electrochemically in the accessible potential range. 相似文献
77.
Georgiy V. Malkov Alexey V. Shastin Yakov I. Estrin Elmira R. Badamshina Yuriy M. Mikhailov 《Macromolecular Symposia》2010,296(1):107-111
The results of the kinetic study of melt and solution polymerization at the 1,3-dipolar cycloaddition reaction of the AB2 monomer – 2-azido-4,6-bis(prop-2-yn-1-yloxy)-[1,3,5]-triazine (ABPOT) are presented in this work as well as the results of the 13C-NMR characterization of the obtained hyperbranched poly([1,2,3]-triazole-[1,3,5]-triazine)s. It is established, that the first-shell substitution effect during polyaddition process and unusual high degree of branching (up to 0.9) of polymers synthesized in melt are held. 相似文献