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A coordination polymer formulated as [Sr(H2BTEC)(H2O)] n (H4BTEC = benzene-1,2,4,5-tetra-carb-oxy-lic acid, C10H6O8), was synthesized hydro-thermally and characterized by single-crystal and powder X-ray diffraction, scanning electron microscopy and thermal analysis. Its crystal structure is made up of a zigzag inorganic chain formed by edge-sharing of [SrO8] polyhedra running along [001]. Adjacent chains are connected to each other via the carboxyl-ate groups of the ligand, resulting in a double-layered network extending parallel to (100). O-H⋯O hydrogen bonds of medium-to-weak strength between the layers consolidate the three-dimensional structure. One of the carb-oxy-lic OH functions was found to be disordered over two sets of sites with half-occupancy. © Mokhtari et al. 2020.The crystal structure of the polymeric title compound, catena-poly[[[di-aqua-lithium]-μ-γ-cyclo-dextrin(1-)-[aqua-lithium]-μ-γ-cyclo-dextrin(1-)] pentadecahydrate], [Li2(C48H79O40)2(H2O)3]·15H2O n , consists of deprotonated γ-cyclo-dextrin (CD) mol-ecules assembled by lithium ions into metal-organic ribbons that are cross-linked by multiple O-H⋯O hydrogen bonds into sheets extending parallel to (01). Within a ribbon, one Li+ ion is coordinated by one deprotonated hydroxyl group of the first γ-CD torus and by one hydroxyl group of the second γ-CD torus as well as by two water mol-ecules. The other Li+ ion is coordinated by one deprotonated hydroxyl and by one hydroxyl group of the second γ-CD torus, by one hydroxyl group of the first γ-CD torus as well as by one water mol-ecule. The coordination spheres of both Li+ cations are distorted tetra-hedral. The packing of the structure constitute channels along the a axis. Parts of the hy-droxy-methyl groups in cyclo-dextrin molecules as well as water mol-ecules show two-component disorder. Electron density associated with additional disordered solvent mol-ecules inside the cavities was removed with the SQUEEZE [Spek (2015 ▸). Acta Cryst. C71, 9-18] routine in PLATON. These solvent mol-ecules are not considered in the given chemical formula and other crystal data. Five out of the sixteen hy-droxy-methyl groups and one water mol-ecule are disordered over two sets of sites. © Krukle-Berzina et al. 2020.The asymmetric unit of the title compound, C23H28O4, comprises two half-mol-ecules, with the other half of each mol-ecule being completed by the application of twofold rotation symmetry. The two completed mol-ecules both have a V-shaped appearance but differ in their conformations. In the crystal, each independent mol-ecule forms chains extending parallel to the b axis with its symmetry-related counterparts through C-H⋯π(ring) inter-actions. Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (65.4%), H⋯C/C⋯H (21.8%) and H⋯O/O⋯H (12.3%) inter-actions. Optimized structures using density functional theory (DFT) at the B3LYP/6-311 G(d,p) level are compared with the experimentally determined mol-ecular structures in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap. © Taia et al. 2020.Three huntite-type aluminoborates of stoichiometry REAl3(BO3)4 (RE = Tb, Dy and Ho), namely, terbium/dysprosium/holmium trialuminium tetrakis(borate), were synthesized by slow cooling within a K2Mo3O10 flux with spontaneous crystallization. The crystal structures were determined using single-crystal X-ray diffraction (SC-XRD) data. The synthesized borates are isostructural to the huntite [CaMg3(CO3)4] structure and crystallized within the trigonal R32 space group. The structural parameters were compared to literature data of other huntite REAl3(BO3)4 crystals within the R32 space group. All three borates fit well into the trends calculated from the literature data. Afatinib datasheet The unit-cell parameters and volumes increase linearly with larger RE cations whereas the densities decrease. All of the crystals studied were refined as inversion twins. © Chong et al. 2020.The title pyrazine dicarboxamide ligand, N 2,N 3-bis-(quinolin-8-yl)pyrazine-2,3-dicarboxamide (H2L1), C24H16N6O2, has a twisted conformation with the outer quinoline groups being inclined to the central pyrazine ring by 9.00 (6) and 78.67 (5)°, and by 79.94 (4)° to each other. In the crystal, molecules are linked by C-H⋯O hydrogen bonds, forming layers parallel to the (10) plane, which are in turn linked by offset π-π inter-actions [inter-centroid distances 3.4779 (9) and 3.6526 (8) Å], forming a supra-molecular three-dimensional structure. Reaction of the ligand H2L1 with Cu(ClO4)2 in aceto-nitrile leads to the formation of the binuclear complex, [μ-(3-hy-droxy[(quinolin-8-yl)imino]-meth-ylpyrazin-2-yl)[(quinolin-8-yl)imino]-methano-lato]bis-[diaceto-nitrile-copper(II)] tris-(per-chlor-ate) aceto-nitrile disolvate, [Cu2(C24H15N6O2)(CH3CN)4](ClO4)3·2CH3CN or [Cu2(HL1-)(CH3CN)4](ClO4)3·2CH3CN (I). In the cation of complex I, the ligand coordinates to the copper(II) atoms in a bis-tridentate fashion. A resonance-assisted O-H⋯O hydrogen bond is present in the ligand; the position of this H atom was located in a difference-Fourier map. Both copper(II) atoms are fivefold coordinate, being ligated by three N atoms of the ligand and by the N atoms of two aceto-nitrile mol-ecules. The first copper atom has a perfect square-pyramidal geometry while the second copper atom has a distorted shape. In the crystal, the cation and perchlorate anions are linked by a number of C-H⋯O hydrogen bonds, forming a supra-molecular three-dimensional structure. © Cati and Stoeckli-Evans 2020.The title compound represents the thallium(I) salt of a substituted 1,2,5-oxa-diazole, [Tl(C3H3N4O3)] n , with amino- and hydroxamate groups in the 4- and 3- positions of the oxa-diazole ring, respectively. In the crystal, the deprotonated hydroxamate group represents an inter-mediate between the keto/enol tautomers and forms a five-membered chelate ring with the thallium(I) cation. The coordination sphere of the cation is augmented to a distorted disphenoid by two monodentately binding O atoms from two adjacent anions, leading to the formation of zigzag chains extending parallel to the b axis. The cohesion within the chains is supported by π-π stacking [centroid-centroid distance = 3.746 (3) Å] and inter-molecular N-H⋯N hydrogen bonds. © Safyanova et al. 2020.
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