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The article presents a paper about bis[2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidin-1-ium] DL-malate. According to the article, a 1:2 salt can be formed from racemic malic acid in which the malate compound is disordered across a centre of inversion. It says that despite of the malic acid being one of the simplest chiral dicarboxylic acids, its role in supramolecular chemistry has not been widely studied.

The article presents a paper about two modes of O-H...O hydrogen bonding used in dimorphs of racemic 6-O-acryloyl-2-O-benzoyl-myo-inositol 1,3,5-orthoformate. It mentions the key role of myo-Inositol 1,3,5-orthoester derivatives in the preparation of biologically relevant myo-inositol phosphates. The study found that orientational changes in a small functional group induce diverse hydrogen-bonding patterns in molecular associations.

The article presents a paper about hydrogen-bonded supramolecular motifs in 2-amino-4,6-dimethoxypyrimidinium picrate and pyrimethaminium picrate dimethyl sulfoxide solvate. It mentions the use of picric acid as an acidic ligand to form salts with polar biomolecules through specific electrostatic or hydrogen-bonding interactions. According to one study, hydrogen bonding plays an important role in molecular recognition and crystal engineering research.

The article presents a paper about tetrameric aggregate of 1,c-3-diphenyltetran-r-1-ol via an R44(8) homodromic ring. According to the authors, the title compound has two chiral centers namely C1 and C3. A view of the tetramer, showing the atom-labelling scheme is provided. One table shows that the four molecules in an asymmetric unit are linked by as many hydrogen bonds in order to constitute a tetramer.

The article presents a paper about a new polymorph of triphenylmethylamine. It looks at hydrogen bond and its importance in a vast number of chemical, biological and materials systems. According to the article, the formation of hydrogen bonds of various types causes a decrease in the total energy of a system and serves as its stabilizing factor.

The article presents a paper about trans-Chlorido(phenyl)bis(triphenyl-phosphine)nickel(II) and its 1:1 cocrystal with chloridobis(triphenyl-phosphine)nickel(I). It mentions the interest attracted by a new class of neutral nickel catalysts based on salicylaldimine or anilinotropone ligands. A view of the crystal packing of cocrystal (3) along c, showing the alternating layers along a is provided.

The article presents a paper about poly[triaqua(µ4-4-carboxybenzenesulfonato-k4O:O':O"':O"')(4-carboxybenzenesulfonato-kO)strontium(II)]. According to the article, the study looks at the coordination modes and two-dimensional network of a novel strontium(II) coordination polymer, [Sr(C7H5O5S)2(H2O)3]n. A view of the coordination unit and the coordination polyhedron of the title compound is provided.

The title compound, [Co(C9H10NO3)2(C2H8N2)]Cl·4H2O, is one of six possible diastereomers of the (1,2-di­amino­ethane)­bis( S-tyrosinato)­cobalt(III) complex. The cobalt(III) ion has an octahedral coordination, with three five-membered chelate rings which have deformed coordination angles and coordinated O atoms in trans positions. In comparison with the previously reported crystal structure of the Δ-C1- cis(O) diastereomer [Miodragović et al. (2001). Enantiomer, 6, 299-308], the compound presented in this paper has more planar five-membered amino­carboxyl­ate rings. Complex cations, chloride anions and water mol­ecules of crystallization are linked together by a network of hydrogen bonds. The chloride anions lie approximately between two Co atoms and form hydrogen bonds with all coordinated NH2 groups. In the crystal structure, there is a weak intermolecular π⋯π interaction between the phenyl rings. [ABSTRACT FROM AUTHOR]

Two errors in the paper by Geupel et al. [ ] are reported. The figures on page i10 are printed in the wrong order, i.e. Fig. 1 should in fact be Fig. 2 and vice versa. The figure captions are given correctly. In the last sentence of the Comment section, the coefficient α of the linear thermal expansion should be replaced by α a (with the subscript referring to the a axis of the orthorhombic unit cell), so that the sentence reads `The α a value is comparable with that obtained from Raman scattering experiments....'. [ABSTRACT FROM AUTHOR]

In the paper by Bhattacharyya et al. [ ], the chemical diagram of the title compound, C20H27NO3, is incorrect. [ABSTRACT FROM AUTHOR]

The crystal structure of the low-temperature Na4Ti5O12 (tetra­sodium penta­titanium dodeca­oxide) phase has been solved and refined from X-ray and neutron powder diffraction data at 295 K. The structure is trigonal, space group P3, with Z = 1, although it is pseudo-centrosymmetric. The O and Na atoms form a distorted close-packed structure, where Ti atoms occupy octahedral sites. [ABSTRACT FROM AUTHOR]

The structure of the title compound, C12H12N2O2S, (I), comprises mol­ecules that form dimers via N-H⃛N hydrogen-bonding interactions and then construct the overall network through N-H⃛O associations. The dihedral angle between the phenyl and thia­zole rings is 42.41 (6)°. [ABSTRACT FROM AUTHOR]

The structure of the title compound, C14H12ClNO2, (I), comprises essentially planar mol­ecules which crystallize in a monoclinic lattice. C-H⃛O interactions exist to both naphtho­quinone O atoms and the Cl atom. [ABSTRACT FROM AUTHOR]

In the title compound, trans-[CoCl(NO2)(C2H8N2)2]ClO4, there are two independent CoIII complexes with a distorted octahedral coordination, and they show an orientational disorder such that the positions of the nitro and chloro ligands are exchanged. As a result, the averaged structure has inversion centres at the Co atoms. The perchlorate-O atoms are disordered over two sites. [ABSTRACT FROM AUTHOR]

The structure of the title compound, C22H18N6O4, (I), comprises two unique mol­ecules that separately form hydrogen-bonded polymer chains via N-H⃛N interactions. Molecular independence arises due to a difference in the dihedral angles between the linked rings, i.e. 52.19 (4) and 46.17 (5)°. [ABSTRACT FROM AUTHOR]

The title compound, dipiperazinium heptazinc hexakis(arsen­ate) dihydrate, is built from vertex-sharing AsO4 tetrahedra, ZnO4 tetrahedra and ZnO5 trigonal bipyramids. The connectivity between these polyhedra give rise to an open framework with eight-ring channels along the crystallographic [001] and [011] directions. The piperazinium cations are located within these channels. [ABSTRACT FROM AUTHOR]

The structure of the title compound, C12H13ClN4, (I), comprises a racemic mixture of chiral mol­ecules associated by N-H⃛N hydrogen-bonding interactions. The dihedral angle between the two rings is 77.90 (6)°. [ABSTRACT FROM AUTHOR]

The structure of the title compound, C14H12ClNO3, (I), comprises essentially planar mol­ecules stacked parallel to the a axis. C-H⃛O hydrogen-bonding interactions exist to both naphtho­quinone O atoms and the Cl atom, but not to the morpholine O atom. [ABSTRACT FROM AUTHOR]

Crystals of the title compound, C9H12O, were formed as an unexpected by-product during the recrystallization of (2 R,3 R)-α,α,α′,α′-tetramesityl-1,4-dioxa­spiro­[4,5]­decane-2,3-di­methanol from hexane/ethyl acetate (7:3). Strong hydrogen bonds between hydroxide groups connect the mol­ecules around one set of four symmetry-equivalent 21 axes. [ABSTRACT FROM AUTHOR]

The structure of the title compound, C30H24Cl12N12S6, (I), comprises six symmetry unique mol­ecules that vary only slightly in their N-C-S-C torsion angle. All the mol­ecules are planar to within less than 3.1°. [ABSTRACT FROM AUTHOR]

In the paper by Rajalakshmi et al. [ ], it is incorrectly stated that `the priority sequence attached to the chiral carbon C24 has an ` R' designation as per the listed coordinates'. This is corrected as `the priority sequence attached to the chiral carbon C24 has an ` S' designation as per the listed coordinates'. [ABSTRACT FROM AUTHOR]

The title compound, [NiCl2(C6H8N2)2], contains centrosymmetric mol­ecules with two phenyl­ene­di­amine ligands coordinated in a bidentate fashion. The Ni-N distances are 2.088 (1) and 2.096 (1) Å, and the Ni-Cl distance of 2.4635 (4) Å. The plane of each phenyl­enedi­amine mol­ecule makes a dihedral angle of 26.53 (7)° with the NiN4 plane. Extensive hydrogen bonding leads to distinct cleavage in the bc plane. [ABSTRACT FROM AUTHOR]

The structure of the title compound, [Cu2(C9H9O3)4(C4H5N3)], comprises a zigzag polymer of alternating tetrakis­(carboxyl­ato- O: O′)­dicopper(II) and 2-amino­pyrimidine units linked by axial Cu-N bonds, and the non-centrosymmetric structure has four unique (3-methoxy­phenyl)­acetate moieties. [ABSTRACT FROM AUTHOR]

In order to determine the absolute configuration of the new chiral auxiliary trans-1,2-cyclo­pentane­diyl­bis(2-benzene­thiol), one of the diastereomeric bis-esters with (−)-menthol, used in the resolution of the auxiliary, was subjected to X-ray study. This (−)-diastereomer proved to be (1 S,2 S)-1,2-bis{2-[(−)-3- p-menthyl­oxy­carbonyl­thio]­phenyl}­cyclo­pentane, C39H54O4S2. [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound, ethyl 2,2-di­­hy­droxy-2-(3-oxo-3,4-di­hydro­quinoxalin-2-yl)­acetate, C12H12N2O5, indicates a short intramolecular contact between the N1 atom and a hydroxyl group [2.772 (4) Å]. Two intermolecular hydrogen bonds participate in the molecular packing. [ABSTRACT FROM AUTHOR]

In the title compound, C9H10N2O2, the amide groups are rotated out of the C(ONH2)-C(HPh)-C(ONH2) plane by ca 25-47° and the phenyl ring is almost perpendicular to this plane. The crystal structure is stabilized by intra- and intermolecular N-H⃛O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the title compound, C17H20N2O, (I), the dihedral angle between the two phenyl rings is 15.69 (6)°. An intermolecular hydrogen-bonding association exists between the hydroxy group and one of the azo N atoms. [ABSTRACT FROM AUTHOR]

The crystal structure of 3-chloro­propion­amide, C3H6ClNO, (I), was determined in order to obtain coordinates for molecular-orbital calculations. Intermolecular N-H⃛O and C-H⃛O hydrogen bonds link the mol­ecules into continuous two-dimensional sheets parallel to the (100) plane. The bond distances are C-Cl 1.793 (3), C=O 1.233 (3) and C-N 1.320 (3) Å. [ABSTRACT FROM AUTHOR]

The title complex, [Eu(C6H4O2)3(H2O)2], has a double carboxyl­ate-bridged infinite-chain structure, with one chelating carboxyl­ate group on each Eu ion centre, which also binds to two water mol­ecules to yield an eight-coordinate square-antiprismatic geometry, with Eu-O bond lengths in the range 2.338 (3)-2.594 (3) Å. The pyridine N atoms of the isonicotinate groups do not coordinate to the Eu ions; instead, they direct the formation of EuIII coordination polymers via hydrogen bonding with coordinated water mol­ecules. [ABSTRACT FROM AUTHOR]

We are very interested in characterizing ligands derived from salicyl­aldehyde and α-amino acids. These ligands form interesting complexes with different transition metals, which are very useful for understanding some biological systems. For Schiff bases derived from salicyl­aldehyde and different alkyl­amines or aryl­amines, the enol-imine form is predominant. The title compound, (I), shows bond distances which are clearly in agreement with the keto-amine form. [ABSTRACT FROM AUTHOR]

In the title compound, N(CH2CH2CN)3, (I), the three cyano­ethyl groups adopt a conformation with the CN groups oriented in the same direction, suggesting the compound may behave as a potential tripodal ligand. [ABSTRACT FROM AUTHOR]

Although mol­ecules of the title compound, 3,4-di­chloro-2,5-dihydro­furan-2,5-dione (di­chloro­maleic anhydride, C4Cl2O3), (I), possess approximate non-crystallographic C2 v symmetry, the two chlorine substituents deviate from the ring plane. Their deviations are in the same direction, but with values of 0.0356 (17) and 0.0167 (17) Å, they differ significantly in magnitude. The closest intermolecular contact is of 2.888 (2) Å between a carbonyl O atom and the C atom of a carbonyl group, with the O⋯C direction orthogonal to the C=O bond [O5⋯C2i=O2i 93.6 (2)°; symmetry code: (i) − x, −½ + y, z]. These contacts form infinite chains of mol­ecules running parallel to the crystallographic b direction. [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound, C28H26, in the monoclinic space group C2/ c has a columnar packing arrangement with a 7.20 Å axis, a feature common to several tetra­phenyl­methanes. [ABSTRACT FROM AUTHOR]

The title compound, [Zr(C7H7)3(C15H17)], (I), crystallizes from light petroleum with two independent mol­ecules in the asymmetric unit. Whereas in the parent mol­ecule, Zr(η5-C5H5)(CH2Ph)3, all three Zr-CH2Ph angles are equal, in (I), they differ significantly. In spite of their different environments, both independent mol­ecules in (I) exhibit a small, an expected, and a large Zr-CH2Ph angle. The angles are similar to those of the closely related tri­benzyl­[η5-(benzyl­di­methyl­silyl)­cyclo­penta­dienyl]­zirconium complex. The smallest Zr-CH2Ph angle and the consequently relatively short Zr⋯C ipso distance are indicative of η2-bonding of the benzyl group. [ABSTRACT FROM AUTHOR]

The title compound, BINAP oxide, C44H32O2P2, (I), was synthesized by direct oxidation of ( R)-(+)-2,2′-bis­(di­phenyl­phosphino)-1,1′-bi­naphthyl (BINAP) with tert-butyl hydro­peroxide in toluene solution. The angle between the naphthyl planes of the bi­naphthyl group is 94.17 (3)°. [ABSTRACT FROM AUTHOR]

In the paper by Kuhl, Farrugia & Kocieński [ Acta Cryst. (1999), C 55, 2041-2043], the published scheme is incorrect. The correct scheme is given below. [ABSTRACT FROM AUTHOR]