A new imidazole-based N-heterocyclic carbene iridium(I) cationic complex with a tetra-fluorido-borate counter-anion, [Ir(C8H12)(C7H12N2)(C18H15P)]BF4, has been synthesized and structurally characterized. The complex cation has a distorted square-planar conformation around the IrI atom, formed by a bidentate cyclo-octa-1,5-diene (COD) ligand, a phosphane ligand, and an N-heterocyclic carbene (NHC) ligand. The complex crystallizes in the triclinic space group P1 with one cationic Ir-NHC complex and one disordered [BF4]- anion in the asymmetric unit. Bond lengths and bond angles are as expected for an Ir-NHC complex. Several non-classical C-H⋯F hydrogen-bonding inter-actions between the various ligands (tri-phenyl-phosphane, NHC, and COD) and the tetra-fluorido-borate anion orient the metal cationic complex and the counter-anion in the crystal structure.
2-De-oxy-d-galactitol, C6H14O5, was prepared by reduction of 2-de-oxy-d-galactose with sodium borohydride (NaBH4) and crystallized from aqueous solution. Colorless block-shaped crystals suitable for single-crystal X-ray diffraction were obtained. The title compound crystallizes in the triclinic space group P1, with two crystallographically independent mol-ecules in the asymmetric unit. In the crystal, the mol-ecules are linked by O-H⋯O hydrogen bonds, forming a three-dimensional hydrogen-bonded network.
The title Schiff base compound, C18H15NO2, was synthesized via the condensation reaction of 4-hy-droxy aniline and 4-meth-oxy-1-naphthaldehyde in ethanol. The dihedral angle between the phenol ring and the mean plane of the naphthalene ring system is 75.81 (6)°. In the crystal, the mol-ecules are linked by O-H⋯N and C-H⋯O hydrogen bonds, enclosing R 3 3(18) ring motifs and forming zigzag chains propagating along the c-axis direction. The chains are linked via C-H⋯π inter-actions forming slabs lying parallel to the ac plane.
The title compound, C27H27NP2, is a new potential asymmetric P,P,N ligand and consists of a di-phenyl-phosphino and a tert-but-yl(pyridin-2--yl)phosphino group bridged by a 1,2-phenyl-ene backbone. The dihedral angles between the central and pendant aromatic rings are 83.07 (6), 85.99 (5) and 82.80 (6)°. In the extended structure, weak C-H⋯π inter-actions link the mol-ecules.
The title compound, C16H13NS, crystallizes in the monoclinic space group P21/c with two independent mol-ecules in the asymmetric unit. Both mol-ecules adopt a non-planar structure. No classical hydrogen bonds are found in the crystal structure.
Single crystals of the title salt, (C5H5BrN)[SnCl3] or [4-BrPyH][SnCl3], were prepared from aqueous solutions of 4-bromo-pyridinium hydro-chloride, [4-BrPyH]Cl, and tin dichloride, SnCl2. The cation has bond lengths and angles similar to those found in its other salts. In its first coordination sphere, the anion has a trigonal-pyramidal, tpy, structure with the SnII atom at the apex and the three chlorine atoms at the base. The tin-chlorine bond lengths are all greater than 2.5 Å and the bond angles are all less than 92°, which indicates the presence of tetrel bonds. These occur along the twofold screw-axis in the b-axis direction and extend the coordination sphere of the tin atom to a highly distorted, 33-aaa octa-hedron. In the crystal, the cations are stacked parallel to one another at varying distances along the a-axis direction, with weak π-π inter-actions occurring on both sides. Additional N-H⋯Cl hydrogen bonds are bifurcated and weak.
The structure of the title compound, C7H8N2O2, is reported and completes structural characterization for the family of methyl-2-nitro-aniline isomers. Bond lengths and angles conform to reported values in other methyl-2-nitro-aniline structures, except for the large angle [36.82 (4)°] formed between the phenyl ring and nitro group mean planes. This large angle is due to steric crowding by the neighboring methyl group, a result that is confirmed by an ab initio geometry optimization in vacuo that yields a similar inter-planar angle (38.28°). In the extended structure, the mol-ecules form inversion-related pairs that belong to neighboring supra-molecular spiral stacks parallel to c. The stacks form around a 41 axis with N-H⋯N hydrogen bonding between mol-ecules related by -1/4 of a turn at the core and peripheral N-H⋯O hydrogen bonds to mol-ecules related by +3/4 of a turn.
The title compound, C26H22F3NO2, crystallizes with two independent mol-ecules in the asymmetric unit with very similar geometries. The two mol-ecules are characterized by a short (H⋯F ≃ 2.13 Å) intra-molecular C-H⋯F hydrogen bond between the central methine C atom and the CF3 group. The cyclo-hexenone rings adopt envelope conformations, with a maximum deviation of a methyl-ene C atom of 0.55 (6) and 0.63 (5) Å in one mol-ecule and 0.61 (5) and 0.64 (5) Å in the other. The tri-fluoro-methyl-phenyl and phenyl rings are almost normal to the di-hydro-pyridine mean plane, with dihedral angles lying between 84.35 (9) and 88.81 (8)°.
The title compound, [Ag(C6H13N3P)4(C6H12N3P)](CO3)2 or [Ag(PTAH)3(PTA)](CO3)2, is a discrete cationic silver(I) complex composed of one neutral 1,3,5-tri-aza-7-phosphaadamantane (C6H12N3P; PTA) ligand and three monoprotonated PTAH+ (C6H13N3P+) ligands coordinated to the silver center, resulting in an overall +4 charge balanced by two carbonate anions. The compound crystallizes in the rhombohedral R3 space group with the silver ion and PTA P atom lying on a crystallographic threefold axis, as does one of the carbonate C atoms. The silver ion adopts a tetra-hedral geometry with P-Ag-P bond angles near the ideal 109°, and silver-phospho-rus bond distances of 2.4699 (6) and 2.4683 (11) Å for Ag-PPTA and Ag-PPTAH, respectively. The crystal packing features N-H⋯O hydrogen bonds between the protonated N atoms of the PTAH ligands and the non-coordinating carbonate anions.
The title compound, C20H19F3O4, crystallizes with two independent mol-ecules with similar geometry. In both mol-ecules the tetra-hydro-pyran, cyclo-hexene and cyclo-hexane rings of the xanthene moiety adopt half-chair, half-boat and chair conformations, respectively. In the extended structure, O-H⋯O hydrogen bonds between hy-droxy and carbonyl groups link mol-ecules into chains propagating along [100].
The title compound, C25H36N2O, crystallized with two independent mol-ecules in the asymmetric unit each with statistical proton disorder within the formamidine backbone, thereby indicating the coexistence of zwitterionic and neutral tautomers. The mol-ecular conformation is described by the dihedral angles between each phenyl ring plane and the formamidine backbone, which are 79.8 (3) and 76.0 (3)°, and by the dihedral angle between the two phenyl ring planes, which is 59.61 (11)°. In the crystal, O-H⋯O and N-H⋯N hydrogen bonds connect the neutral and zwitterionic mol-ecules into cyclic dimers. The methyl groups of one isopropyl residue are statistically disordered.
The tricyclic mol-ecule of the title compound, C12H14O2, is composed of four nearly planar subunits. Hydrogen bonds connect the ketol units to chains along the a-axis direction. The structure is further consolidated by two C-H⋯O hydrogen bonds, one to the carbonyl and one to the hy-droxy group.
Colourless, needle-like single crystals of the title compound, Sr[SnF6]·2H2O, were grown from stoichiometric amounts of SrF2 and SnF4 in boiling water. The compound is isostructural with the corresponding hexa-fluorido-iridate(IV) and features a nearly undistorted octa-hedral [SnF6]2- anion with C 1 point-group symmetry, as well as an Sr2+ ion in a distorted, square-anti-prismatic coordination environment. The resulting [SrF5(H2O)3] coordination polyhedra share an edge via two water mol-ecules to form centrosymmetric dimers. As the strength of the O-H⋯F and O-H⋯O hydrogen bonds is less pronounced, the crystal packing is dominated by μ 2-F atoms between anions and cations.
Commercially available L-glucose, C 6 H 12 O 6 , was crystallized by slow evaporation from aqueous solution at room temperature affording colorless block-shaped single crystals suitable for single-crystal X-ray diffraction. The title compound crystallizes as α-L-glucose in the orthorhombic space group P 2 1 2 1 2 1 , with one molecule in the asymmetric unit and Z = 4. In the crystal, the molecules are linked by O—H...O hydrogen bonds, forming a three-dimensional hydrogen-bonded network. This study provides an experimentally determined structural dataset for the rare L enantiomer, which is not currently represented in the Cambridge Structural Database.
A systematic survey of monosaccharides in the PDB archive threw up a possible improvement in model fit in pdb_00004dda. Reprocessing of the publicly open archive of the raw diffraction images was made using EVAL . The diffraction resolution was assessed by the CC 1/2 = 0.5 criterion and confirmed by paired model refinement implemented in PDB-REDO . The resulting change in diffraction resolution, from 2.4 Å to 2.0 Å, improved the clarity of the electron density at the monosaccharide binding site. The NAG ( N -acetyl-β-D-glucosamine) was refitted as NDG ( N -acetyl-α-D-glucosamine). This example illustrates the advantages of raw diffraction data archiving, as aimed at by FAIR data polices, allowing reprocessing as agreement on community metrics.
Single-crystals of hexafluoridouranium(VI), UF 6 , were obtained by sublimation. A re-refinement of the crystal structure using low-temperature (100 K) single-crystal X-ray data was carried out considering all U ij terms of the displacement parameters of the U and F atoms, leading overall to a significantly improved structural model. UF 6 crystallizes in the orthorhombic space group Pnma with the F atoms forming a double hexagonal closest packing of ABAC stacking with U atoms in one-sixth of the voids. The UF 6 molecules deviate only slightly from octahedral point-group symmetry.
The crystal structure of diamminecopper(I) divanadate(IV,V), or poly[diamminecopper(I) [tri-μ 3 -oxido-di-μ 2 -oxido-divanadium(IV,V)]], {[Cu(NH 3 ) 2 ]V 2 O 5 } n , has been determined by single-crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P 2 1 / c and consists of infinite {V 2 O 5 } − layers expanding parallel to the bc plane built from edge- and corner-sharing [VO 5 ] square pyramids. Almost linear diamminecopper(I) cations, [Cu(NH 3 ) 2 ] + , are located between the vanadate layers and are linked to the framework through N—H...O hydrogen bonds.
