Kristína Plevová

Publications (2)1.56 Total impact

• Article: Ethyl 1-ethyl-7-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylate: X-ray and DFT studies.

  Vratislav Langer, Pavel Mach, Lubomír Smrčok, Kristína Plevová, Viktor Milata
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  ABSTRACT: The basic building unit in the structure of the title compound, C(14)H(14)FNO(3), is pairs of molecules arranged in an antiparallel fashion, enabling weak C-H···O interactions. Each molecule is additionally involved in π-π interactions with neighbouring molecules. The pairs of molecules formed by the C-H···O hydrogen bonds and π-π interactions form ribbon-like chains running along the c axis. Theoretical calculations based on these pairs showed that, although the main intermolecular interaction is electrostatic, it is almost completely compensated by an exchange-repulsion contribution to the total energy. As a consequence, the dominating force is a dispersion interaction. The F atoms form weak C-F···H-C interactions with the H atoms of the neighbouring ethyl groups, with H···F separations in the range 2.59-2.80 Å.
  Acta crystallographica. Section C, Crystal structure communications 10/2011; 67(Pt 10):o421-4. · 0.78 Impact Factor
• Article: 2-{[(3-Fluorophenyl)amino]methylidene}-3-oxobutanenitrile and 5-{[(3-fluorophenyl)amino]methylidene}-2,2-dimethyl-1,3-dioxane-4,6-dione: X-ray and DFT studies.

  Vratislav Langer, Pavol Mach, Lubomír Smrcok, Viktor Milata, Kristína Plevová
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  ABSTRACT: In the crystal structures of the title compounds, C(11)H(9)FN(2)O, (I), and C(13)H(12)FNO(4), (II), the molecules are joined pairwise via different hydrogen bonds and the constituent pairs are crosslinked by weak C-H...O hydrogen bonds. The basic structural motif in (I), which is partially disordered, comprises pairs of molecules arranged in an antiparallel fashion which enables C-H...N[triple bond]C interactions. The pairs of molecules are crosslinked by two weak C-H...O hydrogen bonds. The constituent pair in (II) is formed by intramolecular bifurcated C-H...O/O' and combined inter- and intramolecular N-H...O hydrogen bonds. In both structures, F atoms form weak C-F...H-C interactions with the H atoms of the two neighbouring methyl groups, the H...F separations being 2.59/2.80 and 2.63/2.71 A in (I) and (II), respectively. The bond orders in the molecules, estimated using the natural bond orbitals (NBO) formalism, correlate with the changes in bond lengths. Deviations from the ideal molecular geometry are explained by the concept of non-equivalent hybrid orbitals. The existence of possible conformers of (I) and (II) is analysed by molecular calculations at the B3LYP/6-31+G** level of theory.
  Acta crystallographica. Section C, Crystal structure communications 08/2010; 66(Pt 8):o392-5. · 0.78 Impact Factor