ABSTRACT
The title hydrated mol-ecular salt (systematic name: tetra-n-butyl-ammonium 2,6-dioxo-1,2,3,6-tetra-hydro-pyrimidine-4-carboxyl-ate monohydrate), C16H36N+·C5H3N2O4 -·H2O, crystallizes with N-Hâ¯O and O-Hâ¯O hydrogen-bonded double-stranded anti-parallel ribbons consisting of the hydro-philic orotate monoanions and water mol-ecules, separated by the bulky hydro-phobic cations. The hydro-phobic and hydro-philic regions of the structure are joined by weaker non-classical C-Hâ¯O hydrogen bonds. An accurate structure analysis conducted at T = 100â K is compared to a lower-resolution less accurate determination using data measured at T = 295â K. The results of both analyses are evaluated using a knowledge-based approach, and it is found that the less accurate room-temperature structure analysis provides geometric data that are similar to those derived from the accurate low-temperature analysis, with both sets of results consistent with previously analyzed structures. A minor disorder of one methyl group in the cation at low temperature was found to be slightly more complex at room temperature; while still involving a minor fraction of the structure, the disorder at room temperature was found to require a non-routine treatment, which is described in detail.
ABSTRACT
In the title complex, chlorido-tetra-kis-(1H-imidazole-κN (3))cobalt(II) chloride, [CoCl(C3H4N2)4]Cl, the Co(II) cation has a distorted square-pyramidal coordination environment. It is coordinated by four N atoms of four imidazole (Im) groups in the basal plane, and by a Cl atom in the apical position. It is isostructural with [Cu(Im)4Cl]Cl [Morzyk-Ociepa et al. (2012 â¸). J. Mol. Struct. 1028, 49-56] and [Cu(Im)4Br]Br [Hossaini Sadr et al. (2004 â¸). Acta Cryst. E60, m1324-m1326]. In the crystal, the [CoCl(C3H4N2)4](+) cations and Cl(-) anions are linked via N-Hâ¯Cl hydrogen bonds, forming layers parallel to (010). These layers are linked via C-Hâ¯Cl hydrogen bonds and C-Hâ¯π and π-π [inter-centroid distance = 3.794â (2)â Å] inter-actions, forming a three-dimensional framework. The IR spectrum shows vibrational bands typical for imidazol groups. The monoclinic unit cell of the title compound emulates an ortho-rhom-bic cell as its ß angle is close to 90°. The crystal is twinned, with the refined ratio of twin components being 0.569â (1):0.431â (1).
ABSTRACT
Single crystals of barium strontium diphosphate, Ba(1.01)Sr(0.99)P(2)O(7), were prepared by a solid-state reaction. The compound is isostructural with α-Ba(2)P(2)O(7), α-Sr(2)P(2)O(7) and BaPbP(2)O(7). The structure has only one diphosphate group of the dichromate type that is repeated by symmetry to form sheets. These sheets present mirror planes perpendicular to the a axis, situated at x = 1/4 and 3/4. All the cations and three of the five independent O atoms are located on these mirror planes. The Ba(2+) cations are nine-coordinated by O atoms. The Ba(2+) and Sr(2+) cations are distributed on three different sites, in contrast with the isostructural compounds where only two sites are fully occupied. The refined site occupancies sum to a Ba:Sr ratio of 1.0133 (18):0.9867 (13), which leads to the reported deviation from the BaSrP(2)O(7) stoichiometry. The Raman spectrum of the compound is also reported and discussed.
ABSTRACT
In the title compound, C(34)H(51)NO(2), the dihedral angle between the planes of the phenyl ring and the carbonyl group is 9.30â (2)°. No significant inter-molecular inter-actions are observed in the crystal structure. The C(5)H(11) fragment is disordered over two positions with site occupancies of 0.611â (6) and 0.389â (6).
ABSTRACT
The title compound, (C(5)H(12)N)(9)[HV(10)O(28)](NO(3))(4), contains a monoprotonated deca-vanadate polyanion which lies on an inversion center. All the piperidinium cations adopt chair conformations. In the crystal structure, inter-molecular N-Hâ¯O hydrogen bonds form chains along [001]. As well as half of a polyanion, the asymmetric unit contains one full and two half-occupancy nitrate ions and four full occupancy and one half-occupancy piperidinium cations; the half-occupancy piperidinium cation is disordered over two general sites with occupancies of 0.32 and 0.18, and is, in turn, disordered over an inversion center.
ABSTRACT
In the title compound, {[Cu(C2O4)(C6H16N2)].4H2O}n, the Cu atom is six-coordinate in a distorted octahedral geometry, and N,N,N',N'-tetramethylethylenediamine acts as a chelating ligand. The oxalate anion, which lies about an inversion centre, bridges the metal cations and forms infinite chains. The structure cohesion is ensured by hydrogen-bonding interactions, which form a three-dimensional framework.