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- Langer, Vratislav, 1949, et al.
(författare)
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(E)-Methyl 2-[(2-fluorophenyl)aminomethylene]-3-oxobutanoate: X-ray and density functional theory (DFT) study
- 2009
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Ingår i: Acta Crystallographica Section C: Crystal Structure Communications. - 0108-2701 .- 1600-5759. ; C65:4, s. o183-o185
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Tidskriftsartikel (refereegranskat)abstract
- The title compound, C12H12FNO3, a potential precursor for fluoroquinoline synthesis, is essentially planar, with the most outlying atoms displaced from the best-plane fit through all non-H atoms by 0.163(2) and 0.118(2) Å. Molecules are arranged in layers oriented parallel to the (011) plane. The arrangement of the molecules in the structure is controlled mainly by electrostatic interactions, as the dipole moment of the molecule is 5.2 D. In addition, the molecules are linked by a weak C-H...O hydrogen bond which gives rise to chains with the base vector [1,1,1]. Electron transfer within the molecule is analysed using natural bond orbital (NBO) analysis. Deviations from the ideal molecular geometry are explained by the concept of non-equivalent hybrid orbitals.
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| 2. |
- Smrcok, L'ubomir, et al.
(författare)
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1,4-diazabicyclo[2.2.2]octane-1,4-diium dihydrogen phosphate monohydrate from X-ray and neutron data
- 2009
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Ingår i: Zeitschrift fur Kristallographie. - : Walter de Gruyter GmbH. - 0044-2968. ; 224:3, s. 174-178
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Tidskriftsartikel (refereegranskat)abstract
- The three-dimensional skeleton of the structure of the title compound is formed by the chains of the hydrogen phosphate units running approximately parallel to the c-axis. The units are coupled to the chains by three types of hydrogen bonds: strong symmetric O-H-O (O center dot center dot center dot O = 2.424(4) and 2.425(4) angstrom) and the moderate P-O-H center dot center dot center dot O-P and P-O center dot center dot center dot(H2O)center dot center dot center dot O-P, respectively. Molecules of the doubly protonated 1,4-diazabicyclo[2.2.2]octane moieties are placed in the voids and in addition for electrostatic interactions they are also hydrogen bonded to the chains of PO4 tetrahedra. The DC conductivity measured at the room temperature along the b-axis is very low (approximate to 7 x 10(-11) S cm(-1)), while in the perpendicular plane it is for more than two or three orders higher and the nonlinear current vs. potential dependence was registered.
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