Crystal structure refinement with SHELXL

Two different products from the reaction of 1-aryl-5-chloro-3-methyl-1H-pyrazole-4-carbaldehyde with cyclohexylamine when the aryl substituent is phenyl or pyridin-2-yl: hydrogen-bonded sheets versus dimers

Cyclohexylamine reacts with 5-chloro-3-methyl-1-(pyridin-2-yl)-1H-pyrazole-4-carbaldehyde to give 5-cyclohexylamino-3-methyl-1-(pyridin-2-yl)-1H-pyrazole-4-carbaldehyde, C16H20N4O, (I), formed by nucleophilic substitution, but with 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde the product is (Z)-4-[(cyclohexylamino)methylidene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one, C17H21N3O, (II), formed by condensation followed by hydrolysis. Compound (II) crystallizes with Z' = 2, and in one of the two independent molecular types the cyclohexylamine unit is disordered over two sets of atomic sites having occupancies of 0.65 (3) and 0.35 (3). The vinylogous amide portion in each compound shows evidence of electronic polarization, such that in each the O atom carries a partial negative charge and the N atom of the cyclohexylamine portion carries a partial positive charge. The molecules of (I) contain an intramolecular N-H...N hydrogen bond, and they are linked by C-H...O hydrogen bonds to form sheets. Each of the two independent molecules of (II) contains an intramolecular N-H...O hydrogen bond and each molecular type forms a centrosymmetric dimer containing one R2(2)(4) ring and two inversion-related S(6) rings.

L-Argininium phosphite - a new candidate for NLO materials

In order to investigate the possibility of salt formation in the L-Arg-H3PO3-H2O system, single crystals of L-argininium phosphite, C6H15N4O2(+)·H2PO3(-), were prepared by evaporation of an aqueous solution containing equimolar quantities of L-arginine and phosphorous acid. The asymmetric unit contains one L-argininium(+) cation and one phosphite [HPO2(OH)](-) anion. The phosphite anions form chains parallel to [010] by O-H...O hydrogen bonding, with an O...O distance of 2.630 (3) Å. The protonated amine and guanidyl groups of the L-argininium(+) cations form N-H...O hydrogen bonds with the carboxylate groups and anions. The IR and Raman spectra are discussed in relation to the crystal structure. The salt displays nonlinear optical (NLO) properties. Another salt was obtained from a solution with a 1:2 molar ratio of components, but was characterized by vibrational spectra only.

The first structurally analysed nucleic acid building block containing the Reese protecting group: 2'-O-[1-(2-fluorophenyl)-4-methoxypiperidin-4-yl]-β-D-(1'R,2'R,3'R,4'R)-uridine

The title compound, C21H26FN3O7, is assembled by N-H...O and O-H...O hydrogen bonds into well-separated two-dimensional layers of about 15 Å thickness. The crescent conformation of the molecules is stabilized by weak intramolecular C-H...O and C-H...F hydrogen bonds. The uridine moiety adopts an anti conformation. The ribofuranose ring exists in an envelope conformation. All the endocyclic uracil bonds are shorter than normal single C-N and C-C bonds, and five of them have comparable lengths, which implies a considerable degree of delocalization of the electron density within this ring.

The crystal and molecular structure of sodium 4-(2,4,6-triisopropylbenzoyl)benzoate in terms of the photochemical behaviour of the anion

Contrary to the known 4-(2,4,6-triisopropylbenzoyl)benzoate salts, di-μ-aqua-bis[tetraaquasodium(I)] bis[4-(2,4,6-triisopropylbenzoyl)benzoate] dihydrate, [Na2(H2O)10](C23H27O3)2·2H2O, (1), does not undergo a photochemical Norrish-Yang reaction in the crystalline state. In order to explain this photochemical inactivity, the intermolecular interactions were analyzed by means of the Hirshfeld surface and intramolecular geometrical parameters describing the possibility of a Norrish-Yang reaction were calculated. The reasons for the behaviour of the title salt are similar crystalline environments for both the o-isopropyl groups in the anion, resulting in similar geometrical parameters and orientations, and that these interaction distances differ significantly from those found in salts where the photochemical reaction occurs.

Synthesis, crystal structure and spectroscopic properties of trans-dibromidobis(2,2-dimethylpropane-1,3-diamine-κ(2)N,N')chromium(III) perchlorate

The title complex salt, trans-anti-[CrBr2(Me2tn)2]ClO4 (where Me2tn = 2,2-dimethylpropane-1,3-diamine, C5H14N2), was prepared and its structure determined by single-crystal X-ray diffraction at 100 K. The asymmetric unit contains three conformationally similar complex cations and three perchlorate anions. In each complex cation, the Cr(III) centre is coordinated by four N atoms of two chelating Me2tn ligands in the equatorial plane and by two Br atoms in a trans-axial arrangement, to give a distorted octahedral geometry. Interionic contacts are dominated by extensive hydrogen bonding, involving the NH groups of the Me2tn ligand as donors and the anion O atoms or coordinated Br atoms as acceptors, resulting in two-dimensional layers in the bc plane. Ligand field analysis based on the angular overlap model, and IR and electronic spectroscopic properties, are also discussed.

Crystal structure of [bis-(2,6-diiso-propyl-phen-yl) phosphato-κO]tris-(methanol-κO)lithium methanol monosolvate

Crystals of the title compound, [Li{OOP(O-2,6-(i)Pr2C6H3)2}(CH3OH)3]·CH3OH or [Li(C24H34O4P)(CH3OH)3]·CH3OH, have been formed in the reaction between HOOP(O-2,6-(i)Pr2C6H3)2 and LiOH in methanol. The title compound is of inter-est as it represents the first reported crystal structure of the family of lithium phosphate diesters. The {Li(CH3OH)3[O2P(O-(i)Pr2C6H3)2]} unit displays the Li atom in a slightly distorted tetra-hedral coordination environment and exhibits one intra-molecular O-H⋯O hydrogen bond between a coordinating methanol mol-ecule and the terminal non-coordinating O atom of the phosphate group. The unit is connected with two non-coordinating methanol mol-ecules through two inter-molecular O-H⋯O hydrogen bonds, and with a neighbouring unit through two other O-H⋯O inter-actions. These inter-molecular hydrogen bonds lead to the formation of infinite chains along [100]. There are no significant inter-actions between the chains.

Crystal structure of β-d,l-psicose

The title compound, C6H12O6, a C-3 position epimer of fructose, was crystallized from an aqueous solution of equimolar mixture of d- and l-psicose (1,3,4,5,6-penta-hydroxy-hexan-2-one, ribo-2-hexulose, allulose), and it was confirmed that d-psicose (or l-psicose) formed β-pyran-ose with a (2) C 5 (or (5) C 2) conformation. In the crystal, an O-H⋯O hydrogen bond between the hy-droxy groups at the C-3 and C-2 positions connects homochiral mol-ecules into a column along the b axis. The columns are linked by other O-H⋯O hydrogen bonds between d- and l-psicose mol-ecules, forming a three-dimensional network. An intra-molecular O-H⋯O hydrogen bond is also observed. The cell volume of racemic β-d,l-psicose [763.21 (6) Å(3)] is almost the same as that of chiral β-d-psicose [753.06 Å(3)].

Crystal structure of the co-crystalline adduct 1,3,6,8-tetra-aza-tri-cyclo-[4.4.1.1(3,8)]dodecane (TATD)-4-bromo-phenol (1/2)

The structure of the 1:2 co-crystalline adduct C8H16N4·2C6H5BrO, (I), from the solid-state reaction of 1,3,6,8-tetra-aza-tri-cyclo-[4.4.1.1(3,8)]dodecane (TATD) and 4-bromo-phenol, has been determined. The asymmetric unit of the title co-crystalline adduct comprises a half mol-ecule of aminal cage polyamine plus a 4-bromo-phenol mol-ecule. A twofold rotation axis generates the other half of the adduct. The primary inter-species association in the title compound is through two inter-molecular O-H⋯N hydrogen bonds. In the crystal, the adducts are linked by weak non-conventional C-H⋯O and C-H⋯Br hydrogen bonds, giving a two-dimensional supra-molecular structure parallel to the bc plane.

The crystal structure of 3-chloro-2-(4-methyl-phenyl)-2H-pyrazolo-[3,4-b]quinoline

In the mol-ecule of 3-chloro-2-(4-methyl-phen-yl)-2H-pyrazolo-[3,4-b]quinoline, C17H12ClN3, (I), the dihedral angle between the planes of the pyrazole ring and the methyl-ated phenyl ring is 54.25 (9)°. The bond distances in the fused tricyclic system provide evidence for 10-π delocalization in the pyrazolo-pyridine portion of the mol-ecule, with diene character in the fused carbocyclic ring. In the crystal, mol-ecules of (I) are linked by two independent C-H⋯N hydrogen bonds, forming sheets containing centrosymmetric R 2 (2)(16) and R 6 (4)(28) rings, and these sheets are all linked together by π-π stacking inter-actions with a ring-centroid separation of 3.5891 (9) Å.

Crystal structure of 1-{3-acetyl-2-(4-chloro-phen-yl)-6-hy-droxy-4-[(2-hy-droxy-prop-yl)amino]-6-methyl-cyclo-hex-3-en-1-yl}ethanone

In the title compound, C20H26ClNO4, the central cyclo-hexene ring adopts an approximate envelope conformation with the C atom binding with the hy-droxy group at the tip of the flap. There is an intramolecular N-H⋯O hydrogen bond generating an S(6) ring motif. In the crystal, classical O-H⋯O hydrogen bonds and weak C-H⋯O and C-H⋯Cl inter-actions link the mol-ecules, forming a three-dimensional supra-molecular architecture. The crystal structure was refined as a four-component twin.

Crystal structure of 2-(11-oxo-10H,11H-indeno-[1,2-b]chromen-10-yl)-2,3-di-hydro-1H-indene-1,3-dione

In the title mol-ecule, C25H14O4, the fused-ring system consisting of four rings is approximately planar, with a dihedral angle of 9.62 (5)° between the planes of the indene ring system and the benzene ring. The di-hydro-indene-1,3-dione unit makes a dihedral angle of 63.50 (2)° with the mean plane of the fused-ring system. A weak C-H⋯O inter-action organizes the mol-ecules into a helical chain along the b axis. In addition, there is a π-π stacking inter-action between the five-membered rings of adjacent fused-ring systems, with a centroid-centroid distance of 3.666 (1) Å.

Crystal structure of di-chlorido-bis-(methyl isonicotinate-κN)copper(II)

In the title compound, [CuCl2(C7H7NO2)2], the square-planar-coordinated Cu(II) ion lies on a centre of symmetry and is bonded to two monodentate methyl-isonicotinate ligands through their N atoms and by two chloride ligands. The mol-ecules pack in a herringbone pattern. Perpendicular to [100] there are weak inter-molecular C-H⋯Cl and C-H⋯O contacts. Along [100] there are infinite chains of edge-sharing octa-hedra linked through the chlorido ligands.

Crystal structure of bis-(3,3-dimethyl-2-oxobut-yl)di-phenyl-phospho-nium bromide chloro-form monosolvate

In the title salt solvate, C24H32O2P(+)·Br(-)·CHCl3, the P atom has a distorted tetra-hedral geometry, and the planes of the phenyl rings form a dihedral angle of 71.86 (14)° with one another. The bromide anion is disordered and was modelled over three positions (occupancy ratio 0.50:0.35:0.15). The crystal also contains one disordered chloro-form solvent mol-ecule that was modeled over three positions (occupancy ratio 0.50:0.35:0.15). Weak inter-molecular inter-actions (C-H⋯Br and C-H⋯O) exist between the complex cation and the bromide anion fragments. The resulting supramolecular structure is an oval-shaped arrangement of phosphonium salt molecules that surround the disordered bromide anion.

Crystal structure of (E)-1-(4-tert-butyl-phen-yl)-2-(4-iodo-phen-yl)ethene

The title compound, C18H19I, crystallized with two independent mol-ecules (A and B) in the asymmetric unit. Both mol-ecules have an E conformation about the bridging C=C bond. They differ in the orientation of the two benzene rings; the dihedral angle being 12.3 (5)° in mol-ecule A, but only 1.0 (6)° in mol-ecule B. In the crystal, the individual mol-ecules are linked by C-I⋯π inter-actions forming zigzag A and zigzag B chains propagating along [001]. The structure was refined as an inversion twin [Flack parameter = 0.48 (2)].

Crystal structure of di-μ-chlorido-bis-[di-chlorido-bis-(methanol-κO)iridium(III)] dihydrate: a surprisingly simple chlorido-iridium(III) dinuclear complex with methanol ligands

The reaction between IrCl3·xH2O in methanol led to the formation of small amounts of the title compound, [Ir2Cl6(CH3OH)4]·2H2O, which consists of two IrCl4O2 octa-hedra sharing an edge via chloride bridges. The mol-ecule lies across an inversion center. Each octa-hedron can be envisioned as being comprised of four chloride ligands in the equatorial plane with methanol ligands in the axial positions. A lattice water mol-ecule is strongly hydrogen-bonded to the coordinating methanol ligands and weak inter-actions with coordinating chloride ligands lead to the formation of a three-dimensional network. This is a surprising structure given that, while many reactions of iridium chloride hydrate are carried out in alcoholic solvents, especially methanol and ethanol, this is the first structure of a chloridoiridium compound with only methanol ligands.

Crystal structure of (E)-hex-2-enoic acid

The crystal structure of the title compound, C6H10O2, an α,β-unsaturated carb-oxy-lic acid, displays carb-oxy-lic acid inversion dimers linked by pairs of O-H⋯O hydrogen bonds. The packing is characterized by layers of acid dimers. All the non-H atoms of the (E)-hex-2-enoic acid mol-ecule lie almost in the same plane (r.m.s. deviation for the non-H atoms = 0.018 Å).

Crystal structure of (E)-pent-2-enoic acid

The mol-ecule of the title compound, C5H8O2, a low-melting α,β-unsaturated carb-oxy-lic acid, is essentially planar [maximum displacement = 0.0239 (13) Å]. In the crystal, mol-ecules are linked into centrosymmetric dimers via pairs of O-H⋯O hydrogen bonds.

Crystal structure of 1-[2-(2,6-di-chloro-phen-yl)-4,5-diphenyl-1H-imidazol-1-yl]propan-2-ol

The central imidazole ring of the title compound, C24H20Cl2N2O, is twisted with respect to with the planes of the 2,6-di-chloro-benzene and two phenyl rings, making dihedral angles of 74.06 (18), 28.52 (17) and 67.65 (18)°, respectively. The phenyl ring not adjacent to the N-bonded 2-hy-droxy-propyl group shows the greatest twist, presumably to minimize steric inter-actions. In the crystal, mol-ecules are linked by O-H⋯N and C-H⋯O hydrogen-bond contacts into chains along the a-axis direction. The series of parallel chains form a two-dimensional sheet approximately parallel to the bc diagonal. In addition, C-H⋯π inter-actions are observed between the sheets. The atoms of the 2-hy-droxy-propyl group and the N atom of the 1H-imidazole ring to which it is bonded are disordered over two sets of sites, with an occupancy ratio of 0.722 (5):0.278 (5). The structure was refined as an inversion twin.

Crystal structure of poly[μ2-aqua-aqua-(μ2-4-nitro-2,5,6-trioxo-1,2,5,6-tetra-hydro-pyridin-3-olato)hemi-μ4-oxalato-barium(II)]

In the title coordination polymer, [Ba(C5HN2O6)(C2O4)0.5(H2O)2] n , the tenfold coordination of the Ba centre consists of four O atoms from the two 4-nitro-2,5,6-trioxo-1,2,5,6-tetra-hydro-pyridin-3-olate (L) anions, three O atoms of two oxalate anions and three water mol-ecules. The Ba-O bond lengths fall in the range 2.698 (3)-2.978 (3) Å. The L ligand chelates two Ba atoms related by a screw axis, leading to formation of fused five- and six-membered chelate rings. Due to the bridging function of the ligands and water mol-ecules, the complex monomers are connected into polymeric two-dimensional layers parallel to the bc plane. Inter-molecular O-H⋯O hydrogen bonds link these layers into a three-dimensional supra-molecular framework.

Crystal structure of 2-(1-methyl-eth-yl)-1,3-thia-zolo[4,5-b]pyridine

In the title mol-ecule, C9H10N2S, one of the methyl groups is almost co-planar with the thia-zolo-pyridine rings with a deviation of 0.311 (3) Å from the least-squares plane of the thia-zolo-pyridine group. In the crystal, weak C-H⋯N hydrogen-bonding inter-actions lead to the formation of chains along [011].

Crystal structure of (1,3-di-tert-butyl-η(5)-cyclo-penta-dien-yl)tri-methyl-hafnium(IV)

The mol-ecule of the title organometallic hafnium(IV) com-pound, [Hf(CH3)3(C13H21)] or [HfMe3(η(5)-C5H3-1,3- (t) Bu2)], adopts the classical three-legged piano-stool geometry for mono-cyclo-penta-dienylhafnium(IV) derivatives with the three methyl groups bonded to the Hf(IV) atom at the legs. The C atoms of the two tert-butyl group bonded to the cyclo-penta-dienyl (Cp) ring are 0.132 (5) and 0.154 (6) Å above the Cp least-squares plane. There are no significant inter-molecular inter-actions present between the mol-ecules in the crystal structure.

Crystal structure of (E)-3-(3,4-di-meth-oxy-phen-yl)-1-(1-hy-droxy-naphthalen-2-yl)prop-2-en-1-one

The mol-ecular structure of the title compound, C21H18O4, consists of a 3,4-di-meth-oxy-phenyl ring and a naphthalene ring system linked via a prop-2-en-1-one spacer. The mol-ecule is almost planar, with a dihedral angle between the benzene ring and the naphthalene ring system of 2.68 (12)°. There is an intra-molecular O-H⋯O hydrogen bond involving the adjacent hy-droxy and carbonyl groups. The mol-ecule has an E conformation about the C=C bond and the carbonyl group is syn with respect to the C=C bond. In the crystal, mol-ecules are linked by bifurcated C-H⋯(O,O) hydrogen bonds, enclosing an R 2 (1)(6) ring motif, and by a further C-H⋯O hydrogen bond, forming undulating sheets extending in b- and c-axis directions. There are π-π inter-actions between the sheets, involving inversion-related naphthalene and benzene rings [inter-centroid distance = 3.7452 (17) Å], forming a three-dimensional structure.

Crystal structure of 4'-bromo-2,3,5,6-tetra-fluoro-biphenyl-4-carbo-nitrile

The title compound, C13H4BrF4N, synthesized from 1,4'-bromo-iodo-benzene and 4-bromo-2,3,5,6-tetra-fluoro-benzo-nitrile in a coupling reaction was found to crystallize in the ortho-rhom-bic space group P212121. The two phenyl rings are rotated with respect to each other by 40.6 (6)°. The mol-ecules inter-act via aryl-perfluoroaryl stacking [3.796 (2) and 3.773 (2) Å], resulting in inter-molecular chains along the a-axis direction. C-H⋯F contacts of about 2.45 Å connect these chains. In contrast to the structure of the parent compound 4'-bromo-biphenyl-4-carbo-nitrile, CN⋯Br contacts that could have given rise to a linear arrangement of the biphenyl mol-ecules desirable for non-linear optical (NLO) materials are not observed in the packing. Instead, several Br⋯F [3.2405 (17) and 3.2777 (18) Å] and F⋯F [2.894 (2) Å] contacts of side-on type II form an inter-molecular network of zigzag chains. The crystal studied was refined as an inversion twin.

Crystal structure of (±)-(1SR,5SR,6SR,7SR,10SR,11SR,13SR)-13-benz-yloxy-7-meth-oxy-meth-oxy-11,15,18,18-tetra-methyl-3-oxo-2,4-dioxa-tetra-cyclo-[12.3.1.0(1,5).0(6,11)]octa-deca-14,16-dien-10-yl benzoate

In the title compound, C36H42O8, the dioxolane ring adopts a twist conformation; the two adjacent C atoms deviate alternately from the mean plane of other atoms by -0.287 (5) and 0.174 (5) Å. The cyclo-hexane, cyclo-hexa-diene and central cyclo-octane rings show chair, half-chair and boat-chair forms, respectively. As a result of the strained ring system, the tetra-subsituted olefin in the cyclo-hexa-diene is skewed from an ideal planar structure. In the crystal, C-H⋯O hydrogen bonds connect the mol-ecules into a sheet parallel to (100). The sheets are further linked by other weak C-H⋯O and C-H⋯π inter-actions, forming a three-dimensional network.

Crystal structure of poly[di-μ-aqua-{5-[(1Z)-2-(4-chloro-phen-yl)-1-cyano-ethenyl]-1,2,3,4-tetra-zol-1-ido-κN (1)}sodium]

In the title compound, [Na(C10H5ClN5)(H2O)2] n , infinite chains of [Na(H2O)2](+) cations having a diamond-shaped cross-section and running parallel to the b axis are formed. O-H⋯N hydrogen bonds to the anions generate layers parallel to (100) which have the chloro-benzene-cyano-ethenyl substituents protruding from both surfaces. The sodium ion makes a short contact of 2.4801 (13) Å with the N atom of the tetra-zolide ring which is syn to the cyano N atom.

Crystal structure of catena-poly[bis-[μ3-2-(2-nitro-phen-yl)acetato-κ(3) O:O:O']disilver(I)]

The title compound, [Ag2(C8H6NO4)2] n , is a silver complex of 2-(2-nitro-phen-yl)acetic acid. The mol-ecules are not conventional crystallographic inversion dimers but consist of two independent ligands and two Ag(I) ions, each with a distorted T-shaped coordination environment. The dihedral angles between acetate groups and the benzene rings are 51.1 (2) and 57.9 (2)°. The nitro groups are oriented at dihedral angles of 23.6 (5) and 32.3 (3)° with respect to the parent benzene rings. The dimers form polymeric chains along the a-axis direction. The Ag⋯Ag separation within a dimer is 2.8200 (5) and between symmetry-related dimers is 3.6182 (5) Å. The polymeric chains are inter-linked by C-H⋯O hydrogen-bond inter-actions.

Crystal structure of bis-(4-meth-oxy-phenyl) malonate

The complete mol-ecule of the title compound, C17H16O6, is generated by crystallographic twofold symmetry, with the central methyl-ene C atom lying on the rotation axis. The carbonyl O atom is disordered over two adjacent positions in a 0.63 (3):0.37 (3) ratio and the dihedral angle between the benzene rings in the two halves of the mol-ecule is 79.31 (12)°. In the crystal, mol-ecules are connected by C-H⋯O hydrogen bonds, generating (110) sheets. Very weak intra-sheet C-H⋯π inter-actions are also observed.

Crystal structure of bis-[N-phenyl-2-(1,2,3,4-tetrahydronaphthalen-1-ylidene)hydrazinecarbothio-amidato-κ(2) N (2),S]zinc dimethyl sulfoxide monosolvate

The reaction of the N-phenyl-2-(1,2,3,4-tetrahydronaphthalen-1-yl-idene)hy-dra-zine-car-bo-thio-amide ligand with zinc acetate dihydrate in a 2:1 molar ratio yielded a yellow solid, which was crystallized from DMSO to obtain the title compound, [Zn(C17H16N3S)2]·C2H6OS. The Zn(II) ion is four-coordinated in a distorted tetra-hedral environment by two deprotonated ligands. Each ligand acts as an N,S-donor, forming a five-membered metallacycle. The maximum deviation from the mean plane of the N-N-C-S chelate group is 0.0029 (14) Å for the N-donor atom of one ligand and 0.0044 (14) Å for the non-coordinating N atom of the second. The dihedral angle between the planes of the two chelate groups is 72.80 (07)°. Bond lengths in the ligands are compared with those in the crystal structure of the free ligand. In the crystal, complex mol-ecules are connected by dimethyl sulfoxide solvate mol-ecules via N-H⋯O hydrogen-bonding inter-actions, building a one-dimensional hydrogen-bonded polymer along the a-axis direction. The S atom and one C atom of the dimethyl sulfoxide solvate mol-ecules are disordered over two sets of sites with an occupancy ratio of 0.6:0.4.

Crystal structures of 2,2'-bipyridin-1-ium 1,1,3,3-tetracyano-2-ethoxyprop-2-en-1-ide and bis(2,2'-bipyridin-1-ium) 1,1,3,3-tetracyano-2-(dicyanomethylene)propane-1,3-diide

In 2,2'-bipyridin-1-ium 1,1,3,3-tetra-cyano-2-eth-oxy-prop-2-en-1-ide, C10H9N2 (+)·C9H5N4O(-), (I), the ethyl group in the anion is disordered over two sets of atomic sites with occupancies 0.634 (9) and 0.366 (9), and the dihedral angle between the ring planes in the cation is 2.11 (7)°. The two independent C(CN)2 groups in the anion make dihedral angles of 10.60 (6) and 12.44 (4)° with the central propenide unit, and the bond distances in the anion provide evidence for extensive electronic delocalization. In bis-(2,2'-bipyridin-1-ium) 1,1,3,3-tetra-cyano-2-(di-cyano-methyl-ene)propane-1,3-diide [alternative name bis-(2,2'-bipyridin-1-ium) tris-(di-cyano-methyl-ene)methane-diide], 2C10H9N2 (+)·C10N6 (2-) (II), the dihedral angles between the ring planes in the two independent cations are 7.7 (2) and 10.92 (17)°. The anion exhibits approximate C 3 symmetry, consistent with extensive electronic delocalization, and the three independent C(CN)2 groups make dihedral angles of 23.8 (2), 27.0 (3) and 27.4 (2)° with the central plane. The ions in (I) are linked by an N-H⋯N hydrogen bond and the resulting ion pairs are linked by two independent C-H⋯N hydrogen bonds, forming a ribbon containing alternating R 4 (4)(18) and R 4 (4)(26) rings, where both ring types are centrosymmetric. The ions in (II) are linked by two independent N-H⋯N hydrogen bonds and the resulting ion triplets are linked by a C-H⋯N hydrogen bond, forming a C 2 (1)(7) chain containing anions and only one type of cation, with the other cation linked to the chain by a further C-H⋯N hydrogen bond.

Crystal structure of 1,1'-{(dodecane-1,12-di-yl)bis-[(aza-niumylyl-idene)methanylyl-idene]}bis-(naphthalen-2-olate)

The title compound, C34H40N2O2, exists in an extended conformation and has crystallographically imposed centrosymmetry. The crystal packing can be described as being composed of parallel layers stacked along [010]. The zwitterionic structure is stabilized by an intra-molecular N-H⋯O hydrogen-bond inter-action.

Crystal structures of (±)-(1SR,5SR,6SR,7SR,10SR,11SR,13RS,14SR)-13-hy-droxy-7-meth-oxy-meth-oxy-11,15,18,18-tetra-methyl-3-oxo-2,4-dioxa-tetra-cyclo-[12.3.1.0(1,5).0(6,11)]octa-dec-15-en-10-yl benzoate, its 13-epimer and 13-one derivative

The title compounds, C29H38O8·0.25C5H12, (A), C29H38O8, (B), and C29H36O8, (C), are tetra-cyclic benzoates possessing a taxane skeleton with a fused dioxolane ring as the core structure. In the asymmetric unit of (A), there are two independent benzoate mol-ecules (A and A') and a half mol-ecule of solvent pentane disordered about an inversion center. The mol-ecular conformations of (A), (B) and (C) are similar except for the flexible meth-oxy-meth-oxy group. The cyclo-hexane, cyclo-hexene and central cyclo-octane rings adopt chair, half-chair and chair-chair (extended crown) forms, respectively. The dioxolane rings are essentially planar, while the dioxolane ring of A' is slightly twisted from the mean plane. In the crystal of (A), inter-molecular O-H⋯O, C-H⋯O and C-H⋯π inter-actions link the independent benzoates alternately, forming a chain structure. In the crystals of (B) and (C), mol-ecules are linked through O-H⋯O and C-H⋯π inter-actions, and C-H⋯O hydrogen bonds, respectively, into similar chains. Further, weak inter-molecular C-H⋯O inter-actions connect the chains into a three-dimensional network in (A) and a sheet in (B), whereas no other interactions are observed for (C).

Crystal structure of tetra-butyl-ammonium bromide-1,2-di-iodo-3,4,5,6-tetra-fluoro-benzene-di-chloro-methane (2/2/1)

The crystallization of a 1:1 molar solution of 1,2-di-iodo-3,4,5,6-tetra-fluoro-benzene (o-DITFB) and tetra-butyl-ammonium bromide (n-Bu4NBr) from di-chloro-methane yielded pure white crystals of a halogen-bonded compound, C16H36N(+)·Br(-)·C6F4I2·0.5CH2Cl2 or [(n-Bu4NBr)(o-DITFB)]·0.5CH2Cl2. The compound may be described as a quaternary system and may be classified as a salt-cocrystal solvate. The asymmetric unit contains one mol-ecule of solvent, two o-DITFB mol-ecules, two cations (n-Bu4N(+)) and two crystallographically distinct bromide ions [θI ⋯ Br- ⋯ I = 144.18 (1) and 135.35 (1)°]. The bromide ion is a bidentate halogen-bond acceptor which inter-acts with two covalently bonded iodines (i.e. halogen-bond donors), resulting in a one-dimensional polymeric zigzag chain network approximately along the a axis. The observed short contacts and angles are characteristic of the non-covalent inter-action [d C-I⋯Br = 3.1593 (4)-3.2590 (5) Å; θC-I⋯Br = 174.89 (7) and 178.16 (7)°]. It is noted that iodine acts as both a halogen-bond donor and a weak CH hydrogen-bond acceptor, while the bromide ions act as acceptors for weak CH hydrogen bonds and halogen bonds.

Crystal structure of 4-hy-droxy-3-meth-oxy-benzaldehyde 4-methyl-thio-semi-carbazone methanol monosolvate

In the title solvate, C15H15N3O2S·CH3OH, the thio-semicarbazone mol-ecule is approximately planar; the maximum deviation from the mean plane is 0.4659 (14) Å and the dihedral angle between the aromatic rings is 9.83 (8)°. This conformation is supported by an intra-molecular N-H⋯N hydrogen bond. In the crystal, the thio-semicarbazone mol-ecules are linked into dimers by pairs of N-H⋯S hydrogen bonds, thereby generating R 2 (2)(8) loops. The methanol solvent mol-ecule bonds to the thio-semicarbazone mol-ecule through a bifurcated O-H⋯(O,O) hydrogen bond and also accepts an O-H⋯O link from the thio-semicarbazone mol-ecule. Together, these links generate a three-dimensional network.

Crystal structure of 4-bromo-2-[(E)-N-(2,2,6,6-tetra-methyl-piperidin-4-yl)carboximido-yl]phenol dihydrate

In the title hydrate, C16H23BrN2O·2H2O, the organic mol-ecule features a strong intra-molecular O-H⋯N hydrogen bond. The piperidine ring, in addition, adopts a chair conformation with the exocyclic C-N bond in an equatorial orientation. The water molecules of crystallization are disordered (each over two sets of sites with half occupancy. In the crystal, they associate into corrugated (100) sheets of (H2O)4 tetra-mers linked by O-H⋯O hydrogen bonds. The organic mol-ecules, in turn, are arranged at both sides of these sheets, linked by water-piperidine O-H⋯N hydrogen bonds.

Crystal structure of ({4-[(4-bromo-phen-yl)ethyn-yl]-3,5-di-ethyl-phen-yl}ethyn-yl)triiso-propyl-silane

The title compound, C29H37BrSi, was synthesized by the Sonogashira coupling of [(3,5-diethyl-4-ethynylphen-yl)ethyn-yl]triiso-propyl-silane with 4-bromo-1-iodo-benzene. In the structure, the two phenyl rings are nearly parallel to each other with a dihedral angle of 4.27 (4)°. In the crystal, π-π inter-actions between the terminal and central phenyl rings of adjacent mol-ecules link them in the a-axis direction [perpendicular distance = 3.5135 (14); centroid-centroid distance = 3.7393 (11) Å]. In addition, there are weak C-H⋯π inter-actions between the isopropyl H atoms and the phenyl rings of adjacent mol-ecules.

Crystal structure of bis-[4-(1H-pyrrol-1-yl)phen-yl] ferrocene-1,1'-di-carboxyl-ate: a potential chemotherapeutic drug

The title iron(II) complex, [Fe(C16H12NO2)2], crystallizes in the ortho-rhom-bic space group Pbca with the Fe(2+) cation positioned on an inversion center. The cyclo-penta-dienyl (Cp) rings adopt an anti conformation in contrast with other substituted ferrocenes in which the Cp rings appear in a nearly eclipsed conformation. The Cp and the aromatic rings are positioned out of the plane, with a twist angle of 70.20 (12)°, and the C(Cp)-C(CO) bond length is shorter than a typical C-C single bond, which suggests a partial double-bond character and delocalization with the Cp π system. The structure of the complex is compared to other functionalized ferrocenes synthesized in our laboratory.

Crystal structure of bis-[trans-(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ(4) N)bis-(thio-cyanato-κN)chromium(III)] tetra-chlorido-zincate from synchrotron data

The structure of the title compound, [Cr(NCS)2(cyclam)]2[ZnCl4] (cyclam = 1,4,8,11-tetra-aza-cyclo-tetra-decane, C10H24N4), has been determined from synchrotron data. The asymmetric unit contains two independent halves of the Cr(III) complex cations and half of a tetra-chlorido-zincate anion. In each complex cation, the Cr(III) atom is coordinated by the four N atoms of the cyclam ligand in the equatorial plane and by two N-bound NCS(-) anions in a trans axial arrangement, displaying a distorted octa-hedral geometry with crystallographic inversion symmetry. The mean Cr-N(cyclam) and Cr-N(NCS) bond lengths are 2.065 (4) and 1.995 (6) Å, respectively. The macrocyclic cyclam moieties adopt centrosymmetric trans-III configurations with six- and five-membered chelate rings in chair and gauche configurations, respectively. The [ZnCl4](2-) anion, which lies about a twofold rotation axis, has a slightly distorted tetra-hedral geometry. The crystal packing is stabilized by hydrogen-bonding inter-actions between the N-H groups of the cyclam ligands, the S atoms of the NCS(-) groups and the Cl(-) ligands of the anion.

Crystal structure of 3-bromo-2-hy-droxy-benzoic acid

Mutual carbox-yl-carboxyl O-H⋯O hydrogen bonds link the mol-ecules of the title compound, C7H5BrO3, into centrosymmetric dimers which display a central R 2 (2)(8) ring motif. In addition, there is an intra-molecular hydrox-yl-carboxyl O-H⋯O inter-action present. A comparison with the crystal structures of 59 other substituted derivatives of salicylic acid shows that both the centrosymmetric carbox-yl-carboxyl O-H⋯O dimer and the stacking mode of mol-ecules along the short a axis observed in the title structure are frequent packing motifs in this set.

Crystal structure of 2-methyl-N-[(4-methyl-pyridin-2-yl)carbamo-thio-yl]benzamide

In the title compound, C15H15N3OS, there is an intra-molecular N-H⋯O hydrogen bond and an intra-molecular C-H⋯S hydrogen bond involving the C=O and C=S bonds which lie on opposite sides of the mol-ecule. The mol-ecule is non-planar with the benzene and pyridine rings being inclined to one another by 26.86 (9)°. In the crystal, mol-ecules are linked by pairs of N-H⋯S hydrogen bonds, forming inversion dimers with an R 2 (2)(8) ring motif. The dimers are linked via C-H⋯S hydrogen bonds, forming slabs parallel to the bc plane.

Crystal structure of 1-nitro-4-(tri-methyl-silylethyn-yl)naphthalene

In the title compound, C15H15NO2Si, the dihedral angle between the nitro group and the mean plane of the naphthalene system is 22.04 (11)°. In the crystal, π-π inter-actions generate supra-molecular chains propagating along the a-axis direction; the centroid-to-centroid distances range from 3.5590 (12) to 3.8535 (12) Å.

Crystal structure of 5,5'-di-bromo-3,3'-di-tert-butyl-6,6'-di-methyl-biphenyl-2,2'-diol

The whole mol-ecule of the title compound, C22H28Br2O2, is generated by twofold rotation symmetry. The dihedral angle of the biphenyl moiety is 85.05 (11)°. The hy-droxy groups show intra-molecular O-H⋯π inter-actions without any other hydrogen-bond acceptors. In the crystal, there are no other significant inter-molecular inter-actions present.

Crystal structure of 5-{3-[2,6-dimethyl-4-(5-methyl-1,2,4-oxa-diazol-3-yl)phen-oxy]prop-yl}-N-(11-hy-droxy-undec-yl)isoxazole-3-carboxamide hemihydrate

The title compound, C29H42N4O5·0.5H2O, comprises four structural units. A flexible prop-yloxy unit in a gauche conformation, with a -C(H2)-C(H2)-C(H2)-O- torsion angle of -64.32 (18)°, connects an isoxazole ring and an approximately planar phenyl-oxa-diazole ring system [with a maxixmum devation of 0.061 (2) Å], which are oriented almost parallel to one another with a dihedral angle of 10.75 (7)°. Furthermore, a C11-alkyl chain with a terminal hy-droxy group links to the 3-position of the isoxazole ring via an amide bond. In the crystal, a half-occupancy solvent water mol-ecule connects to a neighbouring mol-ecule via an inter-molecular O-H⋯O(water) hydrogen bond to the C11-alkyl chain hy-droxy group.

Crystal structure of 2-{(E)-[(2-hy-droxy-phen-yl)iminium-yl]meth-yl}-4-methyl-phenolate

The title compound, C14H13NO2, exists as a zwitterion in the solid state, with the H atom of the phenol group transferred to the imine N atom. The dihedral angle between the planes of the benzene rings is 10.13 (9)°. Intra-molecular N-H⋯O hydrogen bond generate S(6) and S(5) loops. In the crystal, mol-ecules are connected by O-H⋯O hydrogen bonds, generating C(9) chains propagating in the [010] direction.

Crystal structure of bis-[4-(di-methyl-amino)-pyridine-κN (1)]bis-(methanol-κO)bis-(thio-cyanato-κN)manganese(II)

The whole mol-ecule of the title compound, [Mn(NCS)2(CH3OH)2(C5H6N2)2], is generated by inversion symmetry. The Mn(II) ion, which is located on an inversion center, is coordinated by two 4-(di-methyl-amino)-pyridine ligands, two methanol ligands and two terminally N-bonded thio-cyanate anions, forming a slightly distorted octa-hedron. In the crystal, mol-ecules are linked by O-H⋯S hydrogen bonds, forming chains extending along the a-axis direction.

Crystal structure of di-methyl-ammonium hydrogen oxalate hemi(oxalic acid)

Single crystals of the title salt, Me2NH2 (+)·HC2O4 (-)·0.5H2C2O4, were isolated as a side product from the reaction involving Me2NH, H2C2O4 and Sn(n-Bu)3Cl in a 1:2 ratio in methanol or by the reaction of the (Me2NH2)2C2O4 salt and Sn(CH3)3Cl in a 2:1 ratio in ethanol. The asymmetric unit comprises a di-methyl-ammonium cation (Me2NH2 (+)), an hydrogenoxalate anion (HC2O4 (-)), and half a mol-ecule of oxalic acid (H2C2O4) situated about an inversion center. From a supra-molecular point of view, the three components inter-act together via hydrogen bonding. The Me2NH2 (+) cations and the HC2O4 (-) anions are in close proximity through bifurcated N-H⋯(O,O) hydrogen bonds, while the HC2O4 (-) anions are organized into infinite chains via O-H⋯O hydrogen bonds, propagating along the a-axis direction. In addition, the oxalic acid (H2C2O4) mol-ecules play the role of connectors between these chains. Both the carbonyl and hydroxyl groups of each diacid are involved in four inter-molecular inter-actions with two Me2NH2 (+) and two HC2O4 (-) ions of four distinct polymeric chains, via two N-H⋯O and two O-H⋯O hydrogen bonds, respectively. The resulting mol-ecular assembly can be viewed as a two-dimensional bilayer-like arrangement lying parallel to (010), and reinforced by a C-H⋯O hydrogen bond.

Crystal structure of bis-[1,3-bis-(2,6-diiso-propyl-phen-yl)imidazol-2-yl-idene]silver(I) chloride tetrahydro-furan monosolvate

In the title salt, [Ag(C27H36N2)2]Cl·C4H8O, the Ag(I) atom is coordinated by two 1,3-bis-(2,6-di-methyl-phen-yl)imidazol-2-yl-idene ligands. The imidazole rings are inclined to one another by 46.69 (13)° and the benzene rings in each ligand are almost normal to the imdazole ring to which they are attached, with dihedral angles varying from 82.39 (13) to 88.27 (12)°. There are C-H⋯π inter-actions present in the cation, involving the two ligands, and the solvent mol-ecule is linked to the cation via a C-H⋯O hydrogen bond. In the crystal, mol-ecules are linked by trifurcated C-H⋯(Cl,Cl,Cl) hydrogen bonds, forming slabs parallel to (101). One isopropyl group is disordered over two sets of sites with an occupancy ratio of 0.447 (17):0.553 (17) and the THF mol-ecule is disordered over two positions with an occupancy ratio of 0.589 (6):0.411 (6).

Crystal structure of tetra-kis-(μ3-2-{[1,1-bis-(hy-droxy-meth-yl)-2-oxidoeth-yl]imino-meth-yl}phenolato)tetra-copper(II) ethanol monosolvate 2.5-hydrate

The title compound, [Cu4(C11H13NO4)4]·CH3CH2OH·2.5H2O, is an electronically neutral tetra-nuclear copper(II) complex with a cubane-like Cu4O4 core. The complete molecule has point group symmetry 2. The phenol hy-droxy group and one of the three alcohol hy-droxy groups of each 2-{[tris-(hy-droxy-meth-yl)meth-yl]imino-meth-yl}phenol ligand are depro-ton-ated, while the secondary amine and the other two hy-droxy groups remain unchanged. The Cu(II) atoms in the Cu4O4 core are connected by four μ3-O atoms from the deprotonated alcohol hy-droxy groups. Each of the penta-coordinated Cu(II) ions has an NO4 distorted square-pyramidal environment through coordination to the tridentate Schiff base ligands. The Cu-N/O bond lengths span the range 1.902 (4)-1.955 (4) Å, similar to values reported for related structures. There are O-H⋯O hydrogen-bond inter-actions between the complex molecules and the ethanol and water solvent molecules, leading to the formation of a three-dimensional network. The ethanol solvent molecule is disordered about a twofold rotation axis. One of the two independent water molecules is also located on this twofold rotation axis and shows half-occupancy.

Crystal structure of 3-(2,5-di-meth-oxy-phen-yl)propionic acid

In the crystal of the title compound, C11H14O4, the aromatic ring is almost coplanar with the 2-position meth-oxy group with which it subtends a dihedral of 0.54 (2)°, while the 5-position meth-oxy group makes a corresponding dihedral angle of just 5.30 (2)°. The angle between the mean planes of the aromatic ring and the propionic acid group is 78.56 (2)°. The fully extended propionic side chain is in a trans configuration with a C-C-C-C torsion angle of -172.25 (7)°. In the crystal, hydrogen bonding is limited to dimer formation via R 2 (2)(8) rings. The hydrogen-bonded dimers are stacked along the b axis. The average planes of the two benzene rings in a dimer are parallel to each other, but at an offset of 4.31 (2) Å. Within neighbouring dimers along the [101] direction, the average mol-ecular benzene planes are almost perpendicular to each other, with a dihedral angle of 85.33 (2)°.

Crystal structure of 4-formyl-pyridine semicarbazone hemihydrate

The mol-ecule of the title compound C7H8N4O·0.5H2O, alternatively called (E)-1-(pyridin-4-yl-methyl-ene)semi-carb-azide hemihydrate, is in the E conformation and is almost planar; the r.m.s. deviation of the positions of the atoms of the pyridine ring from the best-fit plane is 0.0039 Å. The C, N and O atoms of the rest of the mol-ecule sits close on this plane with a largest deviation of 0.115 (4) Å for the O atom of the semicarbazone moiety. There is an intra-molecular N-H⋯N hydrogen bond. In the crystal, mol-ecules are linked into an infinite three-dimensional network by classical N-H⋯Os (s = semicarbazone) and Ow-H⋯N (w = water) hydrogen bonds.

Crystal structures of 1-(4-chloro-phen-yl)-2-(di-phenyl-phosphor-yl)ethan-1-one and 1-(di-phenyl-phosphor-yl)-3,3-di-methyl-butan-2-one

The title compounds, C20H16ClO2P, (I), and C18H21O2P, (II), were synthesized via an Arbuzov reaction between an α-bromo-ketone and isopropoxydi-phenyl-phosphane. In the crystals of both compounds, mol-ecules are linked via bifurcated C-H⋯(O,O) hydrogen bonds, forming chains propagating along [100] for (I) and along [010] for (II). The chains are linked via C-H⋯π inter-actions, leading to the formation of sheets lying parallel to (010) for (I) and (001) for (II). The absolute structure of compound (II) was determined by resonant scattering [Flack parameter = 0.088 (14)].