Publications by authors named "Tatiana V Timofeeva"

The crystal structures of two inter-mediates, 4-amino-3,5-di-fluoro-benzo-nitrile, CHFN (), and ethyl 4-amino-3,5-di-fluoro-benzoate, CHFNO (), along with a visible-light-responsive azo-benzene derivative, diethyl 4,4'-(diazene-1,2-di-yl)bis-(3,5-di-fluoro-benzoate), CHFNO (), obtained by four-step synthetic procedure, were studied using single-crystal X-ray diffraction. The mol-ecules of and demonstrate the quinoid character of phenyl rings accompanied by the distortion of bond angles related to the presence of fluorine substituents in the 3 and 5 () positions. In the crystals of and , the mol-ecules are connected by N-H⋯N, N-H⋯F and N-H⋯O hydrogen bonds, C-H⋯F short contacts, and π-stacking inter-actions.

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The title compound, systematic name tris-(μ-perfluoro--phenyl-ene)(μ-3-phenyl-4-chromen-4-one)--trimercury, [Hg(CF)(CHO)], crystallizes in the monoclinic 2/ space group with one flavone (FLA) and one cyclic trimeric perfluoro--phenyl-enemercury (TPPM) mol-ecule per asymmetric unit. The FLA mol-ecule is located on one face of the TPPM acceptor and is linked in an asymmetric coordination of its carbonyl oxygen atom with two Hg centers of the TPPM macrocycle. The angular-shaped complexes pack in zigzag chains where they stack two alternating TPPM-TPPM and FLA-FLA stacking patterns.

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A Cu coordination polymer, -poly[[[aqua-copper(II)]-bis-(μ-4-amino-benz-o-ato)-κ :;κ :] monohydrate], {[Cu(ABA)(HO)]·HO} (ABA = -amino-benzoate, CHNO ), was synthesized and characterized. It exhibits a one-dimensional chain structure extended into a three-dimensional supra-molecular assembly through hydrogen bonds and π-π inter-actions. While the twinned crystal shows a metrically ortho-rhom-bic lattice and an apparent space group , the true symmetry is monoclinic (space group 2/), with disordered Cu atoms and mixed roles of water mol-ecules (aqua ligand/crystallization water).

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Article Synopsis
  • The study focuses on the synthesis and electrochemical properties of various benzoimidazole compounds, which are being explored as n-dopants in organic electron-transport materials.
  • It highlights that 2-aryl substituents stabilize radicals more effectively than 2-alkyl groups, leading to different reactivity patterns in reactions with PCBM and other compounds.
  • The findings reveal significant differences in reactivity based on structural modifications, with certain dimers demonstrating faster reaction rates and unique electrochemical characteristics, as confirmed through crystal structure analysis.
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Substituted acetamides (many of which are chiral) are known to be pharmacologically active. 2-Phenylpropionamide (2PPA) is one of the simplest chiral α-substituted acetamides and thus is of interest as a model compound in the growth and design of pharmaceutical crystals. In this study, the crystal structures of racemic and enantiopure forms of 2PPA were determined for the first time using single crystal X-ray diffraction at 100 K.

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A new pseudopolymorph of berberine, 9,10-dimeth-oxy-5,6-di-hydro-2-7λ-[1,3]dioxolo[4,5-]iso-quinolino-[3,2-]isoquinolin-7-ylium chloride methanol monosolvate, CHNO ·Cl·CHOH, was obtained during co-crystallization of berberine chloride with malonic acid from methanol. The berberine cations form dimers, which are further packed in stacks. The title structure was compared with other reported solvates of berberine chloride: its dihydrate, tetra-hydrate, and ethanol solvate hemihydrate.

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Copper(II) complexes with 1,1,1-trifluoro-4-(4-methoxyphenyl)butan-2,4-dione (H) were synthesized and characterized by elemental analysis, FT-IR spectroscopy, and single crystal X-ray diffraction. The biological properties of H and -[Cu()(DMSO)] () were examined against Gram-positive and Gram-negative bacteria and opportunistic unicellular fungi. The cytotoxicity was estimated towards the HeLa and Vero cell lines.

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[RuCp*(1,3,5-RCH)] {Cp* = η-pentamethylcyclopentadienyl, R = Me, Et} have previously been found to be moderately air stable, yet highly reducing, with estimated D/0.5D (where D and D represent the dimer and the corresponding monomeric cation, respectively) redox potentials of -2.0 V FeCp.

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The geometry of the title mol-ecule [systematic name: 2-(2-nitro-phen-yl)-4-chromen-4-one], CHNO, is determined by two dihedral angles formed by the mean plane of phenyl ring with the mean planes of chromone moiety and nitro group, being 50.73 (5) and 30.89 (7)°, respectively.

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The title compound DBNB, CHNO, has been crystallized and studied by X-ray diffraction, spectroscopic and computational methods. In the title mol-ecule, which is based on a 1,4-distyryl-2,5-di-meth-oxy-benzene core with -nitro-substituted terminal benzene rings, the dihedral angle between mean planes of the central fragment and the terminal phenyl ring is 16.46 (6)°.

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The two isomers 2'-(4-nitro-benzo-yloxy)aceto-phenone (systematic name: 2-acetyl-phenyl 4-nitro-benzoate) () and 2'-(2-nitro-benzo-yloxy)aceto-phenone (systematic name: 2-acetyl-phenyl 2-nitro-benzoate) (), both CHNO, with and positions of the nitro substituent have been crystallized and studied. It is evident that the variation in the position of the nitro group causes a significant difference in the mol-ecular conformations: the dihedral angle between the aromatic fragments in the mol-ecule of is 84.80 (4), while that in the mol-ecule of is 6.

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Crystallization from solutions containing 2,2'-[naphthalene-1,8:4,5-bis(dicarboximide)-'-diyl]-bis(ethylammonium) diiodide ((NDIC2)I) and PbI has been investigated. Eight different materials are obtained, either by variation of crystallization conditions or by subsequent thermal or solvent-induced transformations. Crystal structures have been determined for five materials.

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The three organic two-photon-absorbing cycloalkanone chromophores 2,4-bis[4-(diethylamino)benzylidene]cyclobutanone, CHNO (I), 2,5-bis[4-(diethylamino)benzylidene]cyclopentanone, CHNO (II), and 2,6-bis[4-(diethylamino)benzylidene]cyclohexanone, CHNO (III), were obtained by a reaction between 4-(diethylamino)benzaldehyde and the corresponding cycloalkanone and were characterized by single-crystal X-ray diffraction studies, as well as density functional theory (DFT) quantum-chemical calculations. Molecules of this series have three main fragments, i.e.

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The title compound, CHN·CHN , contains one tetra-methyl-ammonium cation and one 1,1,7,7-tetra-cyano-hepta-2,4,6-trienide anion in the asymmetric unit. The anion is in an all- conjugated C=C bonds conformation. Two terminal C(CN) di-nitrile moieties are slightly twisted from the polymethine main chain to which they are attached [C(CN)/C dihedral angles = 6.

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Two compounds, 1,3-diethyl-5-{(2,4)-6-[()-1,3,3-tri-methyl-indolin-2-yl-idene]hexa-2,4-dien-1-yl-idene}pyrimidine-2,4,6(1,3,5)-trione or TMI, CHNO, and 1,3-diethyl-2-sulfanyl-idene-5-[2-(1,3,3-tri-methyl-indolin-2-yl-idene)ethyl-idene]di-hydro-pyrimidine-4,6(1,5)-dione or DTB, CHNOS, have been crystallized and studied. These compounds contain the same indole derivative donor group and differ in their acceptor groups (in TMI it contains oxygen in the position, and in DTB sulfur) and the length of the π-bridge. In both materials, mol-ecules are packed in a herringbone manner with differences in the twist and fold angles.

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The synthesis, crystal structure studies and solvatochromic behavior of 2-{(2E,4E)-5-[4-(dimethylamino)phenyl]penta-2,4-dien-1-ylidene}malononitrile, CHN (DCV[3]), and 2-{(2E,4E,6E)-7-[4-(dimethylamino)phenyl]hepta-2,4,6-trien-1-ylidene}malononitrile, CHN (DCV[4]), are reported and discussed in comparison with their homologs having a shorter length of the π-conjugated bridge. The compounds of this series have potential use as nonlinear materials with second-order effects due to their donor-acceptor structures. However, DCV[3] and DCV[4] crystallized in the centrosymmetric space group P2/c which excludes their application as nonlinear optical materials in the crystalline state.

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The Z and E isomers of 3-[4-(dimethylamino)phenyl]-2-(2,4,6-tribromophenyl)acrylonitrile, CHBrN, (1), were obtained simultaneously by a Knoevenagel condensation between 4-(dimethylamino)benzaldehyde and 2-(2,4,6-tribromophenyl)acetonitrile, and were investigated by X-ray diffraction and density functional theory (DFT) quantum-chemical calculations. The (Z)-(1) isomer is monoclinic (space group P2/n, Z' = 1), whereas the (E)-(1) isomer is triclinic (space group P-1, Z' = 2). The two crystallographically-independent molecules of (E)-(1) adopt similar geometries.

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Mixed cocrystals derived from electron-rich donor (D) and electron-deficient acceptor (A) molecules showcase electronic, optical, and magnetic properties of interest for a wide range of applications. We explore the structural and electronic properties of a cocrystal synthesized from dithieno[3,2-a:2',3'-c]phenazine (DTPhz) and 7,7,8,8-tetracyanoquinodimethane (TCNQ), which has a mixed-stack packing arrangement of the (π-electronic) face-to-face stacks in a 2:1 D:A stoichiometry. Density functional theory investigations reveal that the primary electronic characteristics of the cocrystal are not determined by electronic interactions along the face-to-face stacks, but rather they are characterized by stronger electronic interactions orthogonal to these stacks that follow the edge-to-edge donor-donor or acceptor-acceptor contacts.

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3-Ethyl-3-phenylpyrrolidin-2-one (EPP) is an experimental anticonvulsant based on the newly proposed α-substituted amide group pharmacophore. These compounds show robust activity in animal models of drug-resistant epilepsy and are thus promising for clinical development. In order to understand pharmaceutically relevant properties of such compounds, we are conducting an extensive investigation of their structures in the solid state.

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In the title mol-ecular salt, CHNO·Cl, two of the C-C-N-O groups in the cation adopt a conformation [torsion angles = 62.86 (11) and -54.95 (13)°] and one an conformation [-177.

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Compounds with polarizable π systems that are susceptible to attack with nucleophiles at C-Hal (Hal = Cl, Br) bonds react with Pd(PPh3)4 to yield net oxidative addition. X-ray structures show that the resulting Pd(PPh3)2Hal groups greatly reduce intermolecular π-π interactions. The Pd-functionalized dyes generally exhibit solution-like absorption spectra in films, whereas their Hal analogues exhibit features attributable to aggregation.

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The title three-dimensional metal-organic framework (MOF) compound, {(NH4)2[Zn2(C9H3O6)2]·2C5H9NO} n , features an anionic framework constructed from Zn(2+) cations and benzene-1,3,5-tri-carboxyl-ate (BTC) organic anions. Charge balance is achieved by outer sphere ammonium cations formed by degradation of di-n-butyl-amine in the solvothermal synthesis of the compound. Binuclear {Zn2(COO)2} entities act as the framework's secondary building units.

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Electron acceptors are important components of π-conjugated materials, but the strong electron-withdrawing properties of the required synthetic intermediates often make them poor substrates in synthetic schemes designed around conventional organometallic cross-coupling. Here, strong benzodiimine-based acceptors, including 5,6-difluoro[2,1,3]benzothiadiazole, 5,6-dicyano[2,1,3]benzothiadiazole, 5,6-dicyanobenzo[d][1,2,3]triazole, 6,7-dicyanoquinoxaline, and 6,7-dinitroquinoxaline, are shown to undergo facile palladium-catalyzed C-H direct arylation with a variety of bromoarenes in moderate to high yields. The electrochemical characteristics of di-2-thienyl derivatives synthesized using this methodology are compared and suggest that, in an electron-transfer sense, 5,6-dicyano[2,1,3]benzothiadiazole is a comparably strong acceptor to benzo[1,2-c:4,5-c']bis[1,2,5]thiadiazole.

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The title compound, [Hg3(C6F4)3]·C6N4, contains one mol-ecule of tetra-cyano-ethyl-ene B per one mol-ecule of mercury macrocycle A, i.e., A•B, and crystallizes in the monoclinic space group C2/c.

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Dimers of 2-substituted N,N'-dimethylbenzimidazoline radicals, (2-Y-DMBI)2 (Y=cyclohexyl (Cyc), ferrocenyl (Fc), ruthenocenyl (Rc)), have recently been reported as n-dopants for organic semiconductors. Here their structural and energetic characteristics are reported, along with the mechanisms by which they react with acceptors, A (PCBM, TIPS-pentacene), in solution. X-ray data and DFT calculations both indicate a longer C-C bond for (2-Cyc-DMBI)2 than (2-Fc-DMBI)2 , yet DFT and ESR data show that the latter dissociates more readily due to stabilization of the radical by Fc.

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