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This article reports [1, 2, 4, 5-tetra(4'-carboxyphenyl)-benzene] (1) and its tetraethyl ammonium and tetrabutylammonium inclusion compounds (C34H21O8−·N+(C2H5)4·H2O (2) C34H21O8−·N+(n-C3H7)4·H2O (3). Compound one eventually forms a "molecular column" along the direction of [110], and the solvent molecules are filled by two adjacent columns to form a stable crystal structure. In compound 2, the tetravalent host anion forms rectangular three-dimensional pores with water molecules by O-H... O hydrogen bonds, two tetraethyl ammonium ions are neatly arranged in the pores to form a tighter structure, In structure 3, the formation of the main skeleton mainly relies on O...H...O hydrogen bond formed by the contact between the proton H shared between the two host anions and the O-H...O generated by the water molecule and one of the two anions. In the three crystal structures, [1, 2, 4, 5-tetra(4'-carboxyphenyl)-benzene], as an "X" polycyclic polycarboxylate aromatic molecule, constructs a large 3 D hole by using its configuration feature. Corresponding solvent molecules and different guest molecules are contained in the 3 D pores, forming various stable crystal structures. [ABSTRACT FROM AUTHOR]

Interaction of 8-lithio-3-tert-butyl-4-oxopyrazolo[5,1-c][1,2,4]triazin-1-ide with elemental sulfur or selenium in THF with further in situ alkylation at –97 °C followed by warming to room temperature furnished a series of 3-tert-butyl-8-X-pyrazolo[5,1-c][1,2,4]triazin-4(6H)-ones (X = n-BuS, n-BuSe, MeSe, PhCH2S) in good yields. 8,8'-Diselanediylbis(3-tert-butylpyrazolo[5,1-c][1,2,4]triazin-4(1H)-one) was also isolated as a by-product in these reactions. One-pot interaction of the n-BuSe substituted derivative with diborane/boron trifluoride led to reduction of the 1,2,4-triazine core and partial elimination of the alkylselanyl moiety. The structures of the synthesized products were established on the basis of IR, 1H, 13C, 2D HMBC 1H–77Se NMR and high resolution mass spectra, as well as X-ray single crystal diffraction analyses. Two of the prepared compounds were also tested for antimicrobial and antifungal activities. [ABSTRACT FROM AUTHOR]

The energetics, structures, reaction paths and mechanisms for the conversion XCN ⟷ XNC, with X = H, Li, CH3 and H2B have been investigated through the use of improved virtual orbitals (IVO) in a second-order multireference perturbation theory (MRPT) treatment within the framework of state-specific (SS) parametrisation of the wave function for the target state (IVO-SSMRPT). Due to its flexibility, IVO-SSMRPT formulation allows us to take into account the major part of the coupling between the dynamic and nondynamic correlation effects in an accurate manner. The results obtained by our calculations agree well with the state-of-the-art electronic structure methods and reference values which illustrates that IVO-SSMRPT, when applied judiciously, can be very accurate for reaction surfaces of XCN ⟷ XNC isomerisation, barrier and bond-parameters. [ABSTRACT FROM AUTHOR]

Mesomorphic properties of three-ring systems such as 2,5-dibenzoyloxytropones, 5-benzoylamino-2-benzoyloxytropones and 2,5-dibenzoylaminotropones with 4-alkoxy, 3,4-dialkoxy, and 3,4,5-trialkoxy groups on the benzoyl groups were investigated together with those of the corresponding benzenoids. Derivatives with two monoalkoxybenzoyl groups showed nematic and smectic A and C phases. Troponoid tetracatenars with two dialkoxybenzoyl groups had hexagonal columnar phases except for troponoids with two ester-connecting groups, whereas the corresponding benzenoids with two dialkoxybenzoyl groups were non-mesomorphic. All troponoid hexacatenars with two trialkoxybenzoyl groups formed hexagonal columnar phases. With the exception of benzenoid hexacatenars with two ester-connecting groups, the benzenoid hexacatenars showed hexagonal and tetragonal columnar phases. These mesomorphic properties were discussed from the standpoint of the difference of the core structure and the connecting group, where the amide-connecting group played a role to induce and enhance mesomorphic properties through hydrogen bonding. [ABSTRACT FROM AUTHOR]

New 5-hydroxymethyl-8-methyl-3-(3-aryl-[1,2,4]oxadiazol-5-yl)-2H-pyrano-[2,3-c]pyridin-2-ones and their esters were synthesized. The structure of obtained compounds was determined through a complete 1H NMR analysis. [ABSTRACT FROM AUTHOR]