Crystal structure refinement with SHELXL

Crystal structure of (E)-2-fluoro-benz-aldehyde (pyridin-2-yl)hydrazone

The title compound, C12H10FN3, is approximately planar: the dihedral angles between the mean plane of the central N-N=C spacer unit and the fluoro-benzene and pyridine rings are 14.50 (13) and 4.85 (15)°, respectively, while the dihedral angle between the aromatic rings is 16.29 (6)°. The F atom lies at the same side of the mol-ecule as the N atom of the pyridine ring. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds generate R 2 (2)(8) loops. Mol-ecules related by translation in the a direction are linked by two π-π stacking inter-actions involving pairs of benzene rings and pairs of pyridine rings. In each case, the ring-centroid separation is 3.8517 (9) Å. Two chains of this type pass through each unit cell, but there are no direction-specific inter-actions between adjacent chains.

Crystal structure of 3-bromo-methyl-2-chloro-6-(di-bromo-meth-yl)quinoline

In the title compound, C11H7Br3ClN, the quinoline ring system is approximately planar (r.m.s. = 0.011 Å). In the crystal, mol-ecules are linked by C-H⋯Br inter-actions forming chains along [10-1]. The chains are linked by C-H⋯π and π-π inter-actions involving inversion-related pyridine rings [inter-centroid distance = 3.608 (4) Å], forming sheets parallel to (10-1). Within the sheets, there are two significant short inter-actions involving a Br⋯Cl contact of 3.4904 (18) Å and a Br⋯N contact of 3.187 (6) Å, both of which are significantly shorter than the sum of their van der Waals radii.

Crystal structures of di-chlorido-palladium(II), -platinum(II) and -rhodium(III) complexes containing 8-(di-phenyl-phosphan-yl)quinoline

The crystal structures of di-chlorido-palladium(II), -platinum(II) and -rhodium(III) complexes containing 8-(di-phenyl-phosphan-yl)quinoline, (SP-4)-[PdCl2(C21H16NP)], (1) [systematic name: di-chlor-ido-(8-di-phenyl-phosphanyl-quinoline)-palladium(II)], (SP-4)-[PtCl2(C21H16NP)]·CH2Cl2, (2) [systematic name: di-chlorido-(8-di-phenyl-phos-phanyl-quinoline)-platinum(II) dichlorometh-ane monosolvate], and (OC-6-32)-[RhCl2(C21H16NP)2]PF6·0.5CH2Cl2·0.5CH3OH, (3) [systematic name: cis-di-chlor-ido-bis-(8-di-phenyl-phosphanyl-quinoline)-rhodium(III) hexa-fluorido-phos-phate di-chloro-methane/-methanol hemisolvate] are reported. In these complexes, the phosphanyl-quinoline acts as a bidentate ligand, forming a planar asymmetrical five-membered chelate ring. The palladium(II) and platinum(II) complex mol-ecules in (1) and (2), respectively, show a typical square-planar coordination geometry and form a dimeric structure through an inter-molecular π-π stacking inter-action between the quinolyl rings. The centroid-centroid distances between the stacked six-membered rings in (1) and (2) are 3.633 (2) and 3.644 (2) Å, respectively. The cationic rhodium(III) complex in (3) has a cis(Cl),cis(P),cis(N) (OC-6-32) configuration of the ligands, in which two kinds of intra-molecular π-π stacking inter-actions are observed: between the quinolyl and phenyl rings and between two phenyl rings, the centroid-centroid distances being 3.458 (2) and 3.717 (2) Å, respectively. The PF6 (-) anion in (3) is rotationally disordered, the site occupancies of each F atom being 0.613 (14) and 0.387 (14). The CH2Cl2 and CH3OH solvent mol-ecules are also disordered and equal site occupancies of 0.5 are assumed.

New insights in the discovery of novel h-MAO-B inhibitors: structural characterization of a series of N-phenyl-4-oxo-4H-chromene-3-carboxamide derivatives

Six N-substituted-phenyl 4-oxo-4H-chromene-3-carboxamides, namely N-(2-nitro-phen-yl)-4-oxo-4H-chromene-3-carboxamide, C16H10N2O5 (2b), N-(3-meth-oxy-phen-yl)-4-oxo-4H-chromene-3-carboxamide, C17H13NO4, (3a), N-(3-bromo-phen-yl)-4-oxo-4H-chromene-3-carboxamide, C16H10BrNO3, (3b), N-(4-methoxy-phen-yl)-4-oxo-4H-chromene-3-carboxamide, C17H13NO4, (4a), N-(4-methyl-phen-yl)-4-oxo-4H-chromene-3-carboxamide, C17H13NO3, (4d), and N-(4-hy-droxy-phen-yl)-4-oxo-4H-chromene-3-carboxamide, C16H11NO4, (4e), have been structurally characterized. All compounds exhibit an anti conformation with respect to the C-N rotamer of the amide and a trans-related conformation with the carbonyl groups of the chromone ring of the amide. These structures present an intra-molecular hydrogen-bonded network comprising an N-H⋯O hydrogen bond between the amide N atom and the O atom of the carbonyl group of the pyrone ring, forming an S(6) ring, and a weak Car-H⋯O hydrogen bond in which the carbonyl group of the amide acts as acceptor for the H atom of an ortho-C atom of the exocyclic phenyl ring, which results in another S(6) ring. The N-H⋯O intra-molecular hydrogen bond constrains the carboxamide moiety such that it is virtually coplanar with the chromone ring.

Crystal structure of 2-(5-bromo-2-hy-droxy-benzyl-idene)-2,3-di-hydro-1H-indene-1,3-dione

The title mol-ecule, C16H9BrO3, deviates slightly from planarity. The benzene ring makes a dihedral angle of 1.02 (9)° with the plane defined by the five-membered ring of the indandione moiety. The latter exhibits a minute twist indicated by the dihedral angle of 0.47 (9)° between the planes of the five- and six-membered rings. An intra-molecular C-H⋯O hydrogen bond between the attached benzene ring with one of the indandione carbonyl O atoms stabilizes the mol-ecular conformation. In the crystal, the mol-ecules form dimers across centres of inversion via pairwise O-H⋯O hydrogen bonds. The dimers form stacks running parallel to [010] and inter-act through π-π inter-actions between the five-membered ring of one mol-ecule and the six-membered rings of the indandione moiety of an adjacent mol-ecule [centroid-to-centroid distance = 3.5454 (10) Å].

Crystal structure of 2-methyl-1H-imidazol-3-ium aqua-tri-chlorido-(oxalato-κ(2) O,O')stannate(IV)

The tin(IV) atom in the complex anion of the title salt, (C4H7N2)[Sn(C2O4)Cl3(H2O)], is in a distorted octa-hedral coordination environment defined by three chlorido ligands, an oxygen atom from a water mol-ecule and two oxygen atoms from a chelating oxalate anion. The organic cation is linked through a bifurcated N-H⋯O hydrogen bond to the free oxygen atoms of the oxalate ligand of the complex [Sn(H2O)Cl3(C2O4)](-) anion. Neighbouring stannate(IV) anions are linked through O-H⋯O hydrogen bonds involving the water mol-ecule and the two non-coordinating oxalate oxygen atoms. In combination with additional N-H⋯Cl hydrogen bonds between cations and anions, a three-dimensional network is spanned.

Crystal structure of 2-chloro-3-(di-meth-oxy-meth-yl)-6-meth-oxy-quinoline

The title compound, C13H14ClNO3, crystallizes with Z' = 2 in the space group Pca21, but a search for possible additional crystallographic symmetry found none. However, the crystal structure exhibits pseudosymmetry as the two independent mol-ecules are related by an approximate but non-crystallographic inversion located close to (0.38, 0.26, 1/2) in the selected asymmetric unit, and the structure exhibits partial inversion twinning. The approximate inversion relationship between the two mol-ecules in the selected asymmetric unit is clearly shown by comparison of the relevant torsion angle in the two mol-ecules; the corresponding torsion angles have similar, although not identical magnitudes but with opposite signs. The mean planes of the quinoline rings in the two independent mol-ecules are almost parallel, with a dihedral angle of only 0.16 (3)° between them, and the mutual orientation of these rings permits significant π-π stacking inter-actions between them [centroid-centroid distances = 3.7579 (15) and 3.7923 (15) Å]. In addition, the bimolecular aggregates which are related by translation along [010] are linked by a further π-π stacking inter-action [centroid-centroid distance = 3.7898 (15) Å], so forming a π-stacked chain running parallel to [010]. However, there are no C-H⋯N hydrogen bonds in the structure nor, despite the number of independent aromatic rings, are there any C-H⋯π hydrogen bonds; hence there are no direction-specific inter-actions between adjacent π-stacked chains.

Crystal structure of methyl 2-hy-droxy-5-[(4-oxo-4,5-di-hydro-1,3-thia-zol-2-yl)amino]benzoate

The title compound, C11H10N2O4S, crystallized with two independent mol-ecules (A and B) in the asymmetric unit. They differ primarily in the rotational orientation of the five-membered heterocyclic ring. In mol-ecule A this ring is inclined to the benzene ring by 48.17 (8)°, while in mol-ecule B the same dihedral angle is 23.07 (8)°. In each mol-ecule there is an intra-molecular O-H⋯O hydrogen bond involving the adjacent hydroxyl group and the ester carbonyl O atom. In the crystal, the A mol-ecules are linked via pairs of N-H⋯N hydrogen bonds, forming inversion dimers. These dimers are linked to the B mol-ecules via N-H.·O, C-H⋯O and C-H⋯S hydrogen bonds forming corrugated sheets lying parallel to (102).

Crystal structure of 4-bromo-phenyl-2-oxo-2H-chromene-3-carboxyl-ate

In the title compound, C16H9BrO4, the coumarin ring system is approximately planar, with an r.m.s deviation of the ten fitted non-H atoms of 0.031 Å, and forms a dihedral angle of 25.85 (10)° with the bromo-benzene ring. The carbonyl atoms are syn. In the crystal, mol-ecules are connected along [001] via C-H⋯O inter-actions, forming C(6) chains. Neighbouring C(6) chains are connected via several π-π inter-actions [range of centroid-centroid distances = 3.7254 (15)-3.7716 (16) Å], leading to sheets propagating in the bc plane.

Crystal structure of rac-(3a'R,9a'R)-3a'-(indol-3-yl)-1',2',3',3a',4',9a'-hexa-hydro-spiro-[cyclo-pentane-1,9'-penta-leno[1,2-b]indole] p-xylene hemisolvate

The title compound, C26H26N2·0.5C8H10, is the first reported characterized 2:2 product from acid-catalyzed condensation of indole with cyclo-penta-none and no other 2:2 products were observed. Recrystallization from p-xylene gave the title hemisolvate with the p-xylene mol-ecule located about an inversion center. The terminal penta-lene ring is envelope-flap disordered at the C atom farthest from the skeletal indole unit, with a refined occupancy ratio of 0.819 (4):0.181 (4). The major component has this C atom bent away from the spiro-fused cyclo-pentane ring. In the crystal, mol-ecules are connected by N-H⋯π inter-actions, forming chains along [100], and N-H⋯π and C-H⋯π inter-actions, forming chains along [001], which results in the formation of slabs parallel to (010).

Crystal structure of tetra-ethyl-ammonium chloride 3,4,5,6-tetra-fluoro-1,2-di-iodo-benzene

Equimolar qu-anti-ties of tetra-ethyl-ammonium chloride (Et4NCl) and 3,4,5,6-tetra-fluoro-1,2-di-iodo-benzene (o-DITFB or o-C6F4I2) have been co-crystallized in a solution of di-chloro-methane yielding a pure halogen-bonded compound, 3,4,5,6-tetra-fluoro-1,2-di-iodo-benzene-tetra-ethyl ammonium chloride (2/1), Et4N(+)·Cl(-)·2C6F4I2, in the form of translucent needles. [(Et4NCl)(o-C6F4I2)2] packs in the C2/c space group. The asymmetric unit includes one mol-ecule of DITFB, one Et4N(+) cation located on a twofold rotation axis, and one chloride anion also located on a twofold rotation symmetry axis. This compound has an inter-esting halogen-bonding environment surrounding the halide. Here, the chloride anion acts as a tetra-dentate halogen bond acceptor and forms a distorted square-pyramidal geometry, with I⋯Cl(-)⋯I angles of 80.891 (6) and 78.811 (11)°, where two crystallographically distinct iodine atoms form halogen bonds with the chloride anion. Resulting from that square-pyramidal geometry are short contacts between some of the adjacent F atoms. Along the b axis, the halogen-bonding inter-action results in a polymeric network, producing a sheet in which the two closest chloride ions are 7.8931 (6) Å apart. The Et4N(+) cation alternates in columns with the halide ion. The expected short contacts (shorter than the sum of their van der Waals radii) are observed for the halogen bonds [3.2191 (2) and 3.2968 (2) Å], as well as almost linear angles [170.953 (6) and 173.529 (6)°].

A square-planar tellurium(II) complex withTe,Te′-chelating ligands

While exploring the chemistry of tellurium-containing dichalcogenidoimidodiphosphinate ligands, the first all-tellurium member of a series of related square-planarEII(E′)4complexes (EandE′ are group 16 elements), namely bis(P,P,P′,P′-tetraphenylditelluridoimidodiphosphinato-κ2Te,Te′)tellurium(II) (systematic name: 2,2,4,4,8,8,10,10-octaphenyl-1λ3,5,6λ4,7λ3,11-pentatellura-3,9-diaza-2λ5,4λ5,8λ5,10λ5-tetraphosphaspiro[5.5]undeca-1,3,7,9-tetraene), C48H40N2P4Te5, was obtained unexpectedly. The formally TeIIcentre is situated on a crystallographic inversion centre and isTe,Te′-chelated to two anionic [(TePPh2)2N]−ligands in ananticonformation. The central TeII(Te)4unit is approximately square planar [Te—Te—Te = 93.51 (3) and 86.49 (3)°], with Te—Te bond lengths of 2.9806 (6) and 2.9978 (9) Å.

Evaluation of New Dihydrophthalazine-Appended 2,4-Diaminopyrimidines against Bacillus anthracis: Improved Syntheses Using a New Pincer Complex

The synthesis and evaluation of ten new dihydrophthalazine-appended 2,4-diaminopyrimidines as potential drugs to treat Bacillus anthracis is reported. An improved synthesis utilizing a new pincer catalyst, dichlorobis[1-(dicyclohexylphosphanyl)-piperidine]palladium(II), allows the final Heck coupling to be performed at 90 °C using triethylamine as the base. These milder conditions have been used to achieve improved yields for new and previously reported substrates with functional groups that degrade or react at the normal 140 °C reaction temperature. An analytical protocol for separating the S and R enantiomers of two of the most active compounds is also disclosed. Finally, the X-ray structure for the most active enantiomer of the lead compound, (S)-RAB1, is given.

Expanding the structural landscape of niclosamide: a highZ′ polymorph, two new solvates and monohydrate HA

Three new crystalline phases are reported for the drug niclosamide [5-chloro-N-(2-chloro-4-nitrophenyl)-2-hydroxybenzamide], C13H8Cl2N2O4. A new high-Z′ polymorph (denoted Form II) is described, with four molecules in the asymmetric unit in the space groupP2/n. The structure exhibits pseudosymmetry, including local translations and screw-type operations. The niclosamide molecules are linked by O—H...O hydrogen bonds into chains, and the chains are packed so that the molecules form face-to-face (stacking) and end-to-end interactions within layers perpendicular to the chains. There are two different layer arrangements, giving a structure that is relatively complex. In the acetone and acetonitrile solvates, the incorporated solvent molecules accept hydrogen bonds from the OH groups of niclosamide, and the niclosamide molecules are stacked in a face-to-face manner. In the acetone solvate, C13H8Cl2N2O4·C3H6O, V-shaped arrangements are formed in which the nitrobenzene ends of the niclosamide molecules are brought into face-to-face contact. In the acetonitrile solvate, C13H8Cl2N2O4·CH3CN, stacking occurs by translation along a short axis (ca3.8 Å) and the crystals are frequently observed to be twinned by twofold rotation around that axis. The acetonitrile molecules occupy channels in the structure. A complete structure is provided for niclosamide monohydrate, C13H8Cl2N2O4·H2O, polymorph HA, obtained by Rietveld refinement against laboratory powder X-ray diffraction data. It has been suggested that this compound is related to the methanol solvate of niclosamide [Harriss, Wilson & Radosevljevic Evans (2014).Acta Cryst.C70, 758–763], but it is found that the two are not fully isostructural: they contain isostructural two-dimensional layers, but the layers are arranged differently in the two structures. This suggests that HAmay have the potential for polytypism, and features in the Rietveld difference curve indicate that a polytype fully isostructural with the methanol solvate might be present.

Synthesis, crystal structure and magnetic properties of (acetato-κ²O,O')bis(5,5'-dimethyl-2,2'-bipyridine-κ²N,N')nickel(II) perchlorate monohydrate

The title hydrated ionic complex, [Ni(CH3COO)(C12H12N2)2]ClO4·H2O or [Ni(ac)(5,5'-dmbpy)2]ClO4·H2O (where 5,5'-dmbpy is 5,5'-dimethyl-2,2'-bipyridine and ac is acetate), (1), was isolated as violet crystals from the aqueous ethanolic nickel acetate-5,5'-dmbpy-KClO4 system. Within the complex cation, the Ni(II) atom is hexacoordinated by two chelating 5,5'-dmbpy ligands and one chelating ac ligand. The mean Ni-N and Ni-O bond lengths are 2.0628 (17) and 2.1341 (15) Å, respectively. The water solvent molecule is disordered over two partially occupied positions and links two complex cations and two perchlorate anions into hydrogen-bonded centrosymmetric dimers, which are further connected by π-π interactions. The magnetic properties of (1) at low temperatures are governed by the action of single-ion anisotropy, D, which arises from the reduced local symmetry of the cis-NiO2N4 chromophore. The fitting of the variable-temperature magnetic data (2-300 K) gives g(iso) = 2.134 and D/hc = 3.13 cm(-1).

A three-dimensional cadmium(II) coordination polymer with unequal homochiral double-stranded concentric helical chains

A homochiral helical three-dimensional coordination polymer, poly[[(μ2-acetato-κ(3)O,O':O)(hydroxido-κO)(μ4-5-nicotinamido-1H-1,2,3,4-tetrazol-1-ido-κ(5)N(1),O:N(2):N(4):N(5))(μ3-5-nicotinamido-1H-1,2,3,4-tetrazol-1-ido-κ(4)N(1),O:N(2):N(4):N(5))dicadmium(II)] 0.75-hydrate], {[Cd2(C7H5N6O)2(CH3COO)(OH)]·0.75H2O}n, was synthesized by the reaction of cadmium acetate, N-(1H-tetrazol-5-yl)isonicotinamide (H-NTIA), ethanol and H2O under hydrothermal conditions. The asymmetric unit contains two crystallographically independent Cd(II) cations, two deprotonated 5-nicotinamido-1H-1,2,3,4-tetrazol-1-ide (NTIA(-)) ligands, one acetate anion, one hydroxide anion and three independent partially occupied water sites. The two Cd(II) cations, with six-coordinated octahedral and seven-coordinated pentagonal bipyramidal geometries are located on general sites. The tetrazole group of one symmetry-independent NTIA(-) ligand links one of the independent Cd(II) cations into 61 helical chains, while the other NTIA(-) ligand links the other independent Cd(II) cations into similar but unequal 61 helical chains. These chains, with a pitch of 24.937 (5) Å, intertwine into a double-stranded helix. Each of the double-stranded 61 helices is further connected to six adjacent helical chains through an acetate μ2-O atom and the tetrazole group of the NTIA(-) ligand into a three-dimensional framework. The helical channel is occupied by the isonicotinamide groups of NTIA(-) ligands and two helices are connected to each other through the pyridine N and carbonyl O atoms of isonicotinamide groups. In addition, N-H···O and O-H···N hydrogen bonds exist in the complex.

Unexpected proline coordination in the copper chain polymer [Cu(μ-Cl)₂(μ-DL-proline-κ²O:O')]¹∞

In catena-poly[copper(II)-di-μ-chlorido-μ-proline-κ(2)O:O'], [CuCl2(C5H9NO2)]n, two symmetry-independent metal cations adopt distorted octahedral coordination, typical for d(9) Jahn-Teller systems. Each chloride bridge is involved in both a short and a very long interaction with a Cu(II) centre. The centrosymmetric crystal structure contains homochiral chains of opposite handedness which extend along the shortest lattice parameter (i.e. a). The O:O'-bridging coordination mode of proline, although a common motif for such complexes in general, is remarkable for Cu(II); the vast majority of amino acid derivatives of this cation are characterized by N,O-chelation.

Three isotypic polymeric complexes with rare earth cations, but-2-enoate anions and 4,4'-(ethane-1,2-diyl)dipyridine and 4,4'-(ethene-1,2-diyl)dipyridine bridging ligands

Three isotypic rare earth complexes, catena-poly[[aquabis(but-2-enoato-κ(2)O,O')yttrium(III)]-bis(μ-but-2-enoato)-κ(3)O,O':O;κ(3)O:O,O'-[aquabis(but-2-enoato-κ(2)O,O')yttrium(III)]-μ-4,4'-(ethane-1,2-diyl)dipyridine-κ(2)N:N'], [Y2(C4H5O2)6(C12H12N2)(H2O)2], the gadolinium(III) analogue, [Gd2(C4H5O2)6(C12H12N2)(H2O)2], and the gadolinium(III) analogue with a 4,4'-(ethene-1,2-diyl)dipyridine bridging ligand, [Gd2(C4H5O2)6(C12H10N2)(H2O)2], are one-dimensional coordination polymers made up of centrosymmetric dinuclear [M(but-2-enoato)3(H2O)]2 units (M = rare earth), further bridged by centrosymmetric 4,4'-(ethane-1,2-diyl)dipyridine or 4,4'-(ethene-1,2-diyl)dipyridine spacers into sets of chains parallel to the [201̄] direction. There are intra-chain and inter-chain hydrogen bonds in the structures, the former providing cohesion of the linear arrays and the latter promoting the formation of broad planes parallel to (010).

Evidence for stereoelectronic effects in the N-C-N group of 8,10,12-triaza-1-azoniatetracyclo[8.3.1.1(8,12).0(2,7)]pentadecane 4-nitrophenolate 4-nitrophenol monosolvate from the protonation of aminal (2R,7R)-1,8,10,12-tetraazatetracyclo[8.3.1.1(8,12).0(2,7)]pentadecane: X-ray and natural bond orbital analysis

The title molecular salt, C11H21N4(+)·C6H4NO3(-)·C6H5NO3, (II), crystallizes with two independent three-component aggregates in the asymmetric unit. In the cations, the cyclohexane rings fused to the cage azaadamantane systems both adopt a chair conformation. In the crystal structure, the aggregates are connected by C-H···O hydrogen bonds, forming a supramolecular unit enclosing an R4(4)(24) ring motif. These units are linked via C-H···O and C-H···N hydrogen bonds, forming a three-dimensional network. Even hydrogen-bond formation to one of the N atoms is enough to induce structural stereoelectronic effects in the normal donor→acceptor direction. The C-N bond distances provide structural evidence for a strong anomeric effect. The structure also displays O-H···O and N-H···O hydrogen bonding. Geometric optimization and natural bond orbital (NBO) analysis of (II) were undertaken by utilizing DFT/B3LYP with the 6-31+G(d,p) basis set. NBO second-order perturbation theory calculations indicate donor-acceptor interactions between nitrogen lone pairs and the antibonding orbital of the C-C and C-N bonds for the protonated polyamine, in agreement with the occurrence of bond-length and bond-angle changes within the aminal cage structure.

A one-dimensional zinc(II) coordination polymer based on mixed multidentate N- and O-donor ligands

In the title coordination polymer, catena-poly[[bis[{1-[(1H-benzimidazol-2-yl-κN(3))methyl]-1H-tetrazole}zinc(II)]-bis(μ4-pentane-1,5-dioato-1:2:1':2'κ(4)O(1):O(1'):O(5):O(5'))] methanol disolvate], {[Zn(C5H6O4)(C9H8N6)]·CH3OH}n, each Zn(II) ion is five-coordinated by four O atoms from four glutarate ligands and by one N atom from a 1-[(1H-benzimidazol-2-yl)methyl]-1H-tetrazole (bimt) ligand, leading to a slightly distorted square-pyramidal coordination environment. Two Zn(II) ions are linked by four bridging glutarate carboxylate groups to generate a dinuclear [Zn2(CO2)4] paddle-wheel unit. The dinuclear units are further connected into a one-dimensional chain via the glutarate ligands. The bimt ligands coordinate to the Zn(II) ions in a monodentate mode and are pendant on both sides of the main chain. In the crystal, the chains are linked by O-H···O and N-H···O hydrogen bonds into a two-dimensional layered structure. Adjacent layers are further packed into a three-dimensional network through van der Waals forces. A thermogravimetric analysis was carried out and the photoluminescent behaviour of the polymer was investigated.

One- and two-dimensional polymers from proline and calcium bromide

Reactions of calcium bromide with enantiopure and racemic proline in aqueous solution lead to two solids in which the zwitterionic amino acid acts as a bridging ligand between neighbouring cations. Depending on the chirality of the amino acid, topologically very different products are obtained. With racemic proline, bromide acts as a simple uncoordinated counter-anion for the cationic heterochiral chains in catena-poly[[aquacalcium(II)]-μ-aqua-μ3-DL-proline-μ2-DL-proline], {[Ca(C5H9NO2)2(H2O)2]Br2}n. In agreement with chemical intuition, only carboxylate and aqua O atoms coordinate the alkaline earth cation in a low-symmetry arrangement. In contrast, L-proline affords the two-dimensional network poly[dibromidobis(μ2-L-proline)calcium(II)], [CaBr2(C5H9NO2)2]n, with an unexpected CaBr2 unit in a more regular coordination sphere.

Crystal structure of {2,2'-[N,N'-bis-(pyridin-2-yl-meth-yl)cyclo-hexane-trans-1,2-diyldi(nitrilo)]di-acetato}-cobalt(III) hexa-fluorido-phosphate

The title compound [Co(C22H26N4O4)]PF6, commonly known as [Co(bpcd)]PF6, where bpcd(2-) is derived from the historical ligand name N,N'-bis-(2-pyridyl-meth-yl)-trans-1,2-di-amino-cyclo-hexane-N,N'-di-acetate, crystallized by slow evaporation of a saturated aceto-nitrile solution in air. The cation of the hexa-fluorido-phosphate salt has the Co(III) atom in a distorted octa-hedral coordination geometry provided by an N4O2 donor atom set. The acetate groups, which are oriented trans with respect to each other, exhibit monodentate coordination whereas the pyridyl N atoms are coordinating in a cis configuration. The geometry of the cation is compared to the geometries of other di-amino di-acetate complexes with Co(III).

Crystal structure of ruthenocenecarbo-nitrile

The mol-ecular structure of ruthenocenecarbo-nitrile, [Ru(η(5)-C5H4C N)(η(5)-C5H5)], exhibits point group symmetry m, with the mirror plane bis-ecting the mol-ecule through the C N substituent. The Ru(II) atom is slightly shifted from the η(5)-C5H4 centroid towards the C N substituent. In the crystal, mol-ecules are arranged in columns parallel to [100]. One-dimensional inter-molecular π-π inter-actions [3.363 (3) Å] between the C N carbon atom and one carbon of the cyclo-penta-dienyl ring of the overlaying mol-ecule are present.

Crystal structure of di-chlorido-{2,6-bis-[(3-phenyl-1H-pyrazol-1-yl)meth-yl]pyridine}cobalt(II)

In the title complex, [CoCl2(C25H21N5)], the Co(II) atom is coordinated by two Cl atoms and two N atoms, provided by a tridentate pyrazolylpyridyl ligand, forming a slightly distorted tetra-hedral geometry [range of angles: 96.51 (10) (chelate ring) to 118.60 (9)°]. The dihedral angle between Cl/Co/Cl and N/Co/N planes is 86.83 (7)°. The chelate ring has the conformation of a distorted boat. The dihedral angle between pyridyl ring and the coordinated pyrazolyl ring is 56.16 (12)°. The uncoordinated pyrazolyl ring is almost perpendicular to the pyridyl ring with the dihedral angle of 87.49 (10)°. In the crystal packing, inter-molecular phenyl-C-H ⋯π(pyrid-yl) inter-actions generate dimeric aggregates. These are connected into a zigzag supra-molecular chain along the c-axis direction via π-π inter-actions [inter-centroid distance between pyridyl and phenyl rings = 3.664 (2) Å].

Crystal structure of 7-[(2E)-2-benzyl-idene-3-oxobut-oxy]-4-methyl-2H-chromen-2-one

Two independent mol-ecules (A and B) comprise the asymmetric unit of the title compound, C21H18O4. There are significant conformational differences between the mol-ecules relating in particular to the relative orientation of the 3-oxo-2-(phenyl-methyl-idene)but-oxy substituent with respect to the superimposable chromen-2-one residues. To a first approximation, the substituents are mirror images; both are approximately perpendicular to the chromen-2-one fused ring system with dihedral angles of 88.50 (7) (A) and 81.96 (7)° (B). Another difference between the independent mol-ecules is noted in the dihedral angles between the adjacent phenyl and but-3-en-2-one groups of 8.72 (12) (A) and 27.70 (10)° (B). The conformation about the ethene bond in both mol-ecules is E. The crystal packing features C-H⋯O, C-H⋯π(ar-yl) and π-π [Cg⋯Cg = 3.6657 (8) and 3.7778 (8) Å] stacking inter-actions, which generate a three-dimensional network.

Crystal structure of (7-chloro-2-oxo-2H-chromen-4-yl)methyl N,N-di-methyl-carbamodi-thio-ate

In the title compound, C13H12Cl N O2S2, the 2H-chromene ring system is almost planar, with a maximum deviation of 0.005 (2) Å. The packing features C-H⋯S hydrogen bonds and π-π inter-actions between fused benzene rings of chromene [shortest centroid-centroid distances = 3.6553 (13) and 3.5551 (13) Å].

Crystal structure of catena-poly[[silver(I)-{μ-2,6-bis-[(1H-pyrazol-1-yl)meth-yl]pyridine-κ(3) N (1),N (2):N (2')}] nitrate]

In the title complex, {[Ag(C13H13N5)]NO3} n , the Ag(I) atom is coordinated by three N atoms from two bidentate/monodentate pyrazolylpyridyl ligands to form a distorted trigonal-planar geometry [range of angles: 83.34 (6) (chelate ring) to 139.15 (7) °]. The chelate ring has a distorted boat conformation. The dihedral angle between the pyridyl ring and the coordinating pyrazolyl ring is 67.22 (6)°. The non-coordinating pyrazolyl ring is twisted by 62.97 (7)° from the pyridyl ring. In the crystal, the complex cations are arranged in polymeric chains along the c-axis direction, with the nitrate counter-anions situated in between. Weak C-H⋯O hydrogen bonds link the ions into a three-dimensional network.

Crystal structure of bis-(4-acetyl-pyridine-κN)bis-(ethanol-κO)bis-(thio-cyanato-κN)manganese(II)

In the crystal structure of the title compound, [Mn(NCS)2(C7H7NO)2(C2H5OH)2], the Mn(II) atom is coordin-ated by two N-bonded thio-cyanate anions, two 4-acetyl-pyridine ligands, and two ethanol mol-ecules within a slightly distorted octa-hedron. The asymmetric unit consits of one manganese cation, located on a centre of inversion, one thio-cyanate anion, one 4-acetyl-pyridine ligand and one ethanol mol-ecule in general positions. The discrete complexes are connected by inter-molecular O-H⋯O hydrogen bonds between the alcohol OH group and the carbonyl O atom into chains parallel to [011].

Tetrahydroberberine, a pharmacologically active naturally occurring alkaloid

Tetrahydroberberine (systematic name: 9,10-dimethoxy-5,8,13,13a-tetrahydro-6H-benzo[g][1,3]benzodioxolo[5,6-a]quinolizine), C20H21NO4, a widely distributed naturally occurring alkaloid, has been crystallized as a racemic mixture about an inversion center. A bent conformation of the molecule is observed, with an angle of 24.72 (5)° between the arene rings at the two ends of the reduced quinolizinium core. The intermolecular hydrogen bonds that play an apparent role in crystal packing are 1,3-benzodioxole -CH2···OCH3 and -OCH3···OCH3 interactions between neighboring molecules.

Crystal structure of tetra-aqua-[2-(pyridin-2-yl)-1H-imidazole-κ(2) N (2),N (3)]iron(II) sulfate

In the title compound, [Fe(C8H7N3)(H2O)4]SO4, the central Fe(II) ion is octa-hedrally coordinated by two N atoms from the bidentate 2-(pyridin-2-yl)-1H-imidazole ligand and by four O atoms of the aqua ligands. The largest deviation from the ideal octa-hedral geometry is reflected by the small N-Fe-N bite angle of 76.0 (1)°. The Fe-N coordination bonds have markedly different lengths [2.1361 (17) and 2.243 (2) Å], with the shorter one to the pyrimidine N atom. The four Fe-O coordination bond lengths vary from 2.1191 (18) to 2.1340 (17) Å. In the crystal, the cations and anions are arranged by means of medium-strength O-H⋯O hydrogen bonds into layers parallel to the ab plane. Neighbouring layers further inter-connect by N-H⋯O hydrogen bonds involving the imidazole fragment as donor group to one sulfate O atom as an acceptor. The resulting three-dimensional network is consolidated by C-H⋯O, C-H⋯π and π-π inter-actions.

Crystal structure of 5-{4'-[(2-{2-[2-(2-ammonio-eth-oxy)eth-oxy]eth-oxy}eth-yl)carbamo-yl]-4-meth-oxy-[1,1'-biphen-yl]-3-yl}-3-oxo-1,2,5-thia-diazo-lidin-2-ide 1,1-dioxide: a potential inhibitor of the enzyme protein tyrosine phosphatase 1B (PTP1B)

The title compound, C24H32N4O8S, (I), crystallizes as a zwitterion. The terminal amine N atom of the [(2-{2-[2-(2-ammonio-eth-oxy)eth-oxy]eth-oxy}eth-yl)carbamo-yl] side chain is protonated, while the 1,2,5-thia-diazo-lidin-3-one 1,1-dioxide N atom is deprotonated. The side chain is turned over on itself with an intra-molecular N-H⋯O hydrogen bond. The 1,2,5-thia-diazo-lidin-3-one 1,1-dioxide ring has an envelope conformation with the aryl-substituted N atom as the flap. Its mean plane is inclined by 62.87 (8)° to the aryl ring to which it is attached, while the aryl rings of the biphenyl unit are inclined to one another by 20.81 (8)°. In the crystal, mol-ecules are linked by N-H⋯O and N-H⋯N hydrogen bonds, forming slabs lying parallel to (010). Within the slabs there are C-H⋯O and C-H⋯N hydrogen bonds and C-H⋯π inter-actions present.

Crystal structure of cis-diamminebis(nitrito-κN)platinum(II)

Single crystals of cis-[Pt(NO2)2(NH3)2], were obtained by means of hyper-saturation directly out of a plating electrolyte. The square-planar coordination environment of the divalent Pt(II) atom is formed by four N atoms belonging to two ammine and two monodentate nitrite ligands. The ligands adopt a cis configuration. The crystal structure contains stacks of close-packed mol-ecules which run parallel to [001]. There are nine crystallographically independent inter-molecular N-H⋯O hydrogen bonds, resulting in a hydrogen-bonded hxl-type framework in which each mol-ecule serves as an eight-connected node. Four of the nine distinct hydrogen bonds connect complexes which belong to the same close-packed column parallel to [001]. In contrast to the previously reported crystal structure of the trans isomer, the title structure does not display intra-molecular hydrogen bonding.

Crystal structure of 1-benzyl-sulfonyl-1,2,3,4-tetra-hydro-quinoline

In the title compound, C16H17NO2S, the heterocyclic ring adopts a half-chair conformation and the bond-angle sum at the N atom is 354.6°. The dihedral angle between the planes of the aromatic rings is 74.15 (10)°. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds, generating C(8) and C(4) chains propagating along [100] and [010], respectively, which together generate (001) sheets.

Crystal structure of 3-methyl-pyridine-2-carbaldehyde 4-methyl-thio-semi-carba-zone monohydrate

In the title hydrate, C9H12N4S·H2O (systematic name: 3-methyl-1-{(E)-[(3-methyl-pyridin-2-yl)methyl-idene]amino}-thio-urea monohydrate), a small twist is noted between the pyridine ring and the rest of the organic mol-ecule [dihedral angle = 6.96 (5)°]. The imine and pyridine N atoms are syn, and the amine H atoms are anti. The latter arrangement allows for the formation of an intra-molecular N-H⋯N(imine) hydrogen bond. Both the N-bonded H atoms form hydrogen bonds to symmetry-related water mol-ecules, and the latter forms O-H hydrogen bonds with the pyridine N and thione S atoms. These inter-actions lead to supra-molecular layers that stack along the a-axis direction with no specific inter-actions between them.

Crystal structure of di-μ-hydroxido-bis-[aqua-(1,10-phenanthroline-κ(2) N,N')copper(II)] naphthalene-2,6-di-carboxyl-ate hexa-hydrate

In the title compound, [Cu2(OH)2(C12H8N2)2(H2O)2](C12H6O4)·6H2O, the two hydroxide groups bridge the two Cu(II) cations, forming a centrosymmetric binuclear complex cation, in which the Cu(II) cation is coordinated by a 1,10-phenanthroline (phen) mol-ecule, one water mol-ecule and two bridging hydroxide O atoms in a distorted N2O3 square-pyramidal coordination geometry. The naphthalene-2,6-di-carboxyl-ate anion is also located on an inversion centre. In the crystal, O-H⋯O hydrogen bonds link the cations, anions and lattice water mol-ecules into a three-dimensional supra-molecular architecture. Extensive π-π stacking is observed between the parallel or nearly parallel aromatic rings of adjacent phen ligands and naphthalenedi-carboxyl-ate anions, the centroid-to-centroid distances ranging from 3.4990 (16) to 3.8895 (16) Å.

Crystal structure of bromido-nitro-syl-bis(tri-phenyl-phosphane-κP)nickel(II)

The asymmetric unit of the title complex, [NiBr(NO){P(C6H5)3}2], comprises two independent mol-ecules each with a similar configuration. The Ni(II) cation is coordinated by one bromide anion, one nitrosyl anion and two tri-phenyl-phosphane mol-ecules in a distorted BrNP2 tetra-hedral coordination geometry. The coordination of the nitrosyl group is non-linear, the Ni-N-O angles being 150.2 (5) and 151.2 (5)° in the two independent mol-ecules. In the crystal, mol-ecules are linked by weak C-H⋯Br hydrogen bonds and weak C-H⋯π inter-actions into a three-dimensional supra-molecular architecture.

Crystal structure of {bis-[2-(3,5-di-methyl-pyrazol-1-yl-κN (2))eth-yl]amine-κN}chlorido-platinum(II) chloride dihydrate

The title complex, [PtCl(C14H23N5)]Cl·2H2O, is isomorphous with the Pd(II) compound characterized previously [Mendoza, Bernès & Mendoza-Díaz (2006 ▶). Acta Cryst. E62, m2934-m2936]. The angle between pyrazole mean planes in the main ligand is 88.3 (4)°, similar to that observed in the Pd(II) analogue [87.62 (11)°]. This tridentate ligand adopts a conformation approximating a twofold symmetry, allowing its coordination to the metal atom, together with a chloride ligand, in an almost perfect square-planar geometry. A chloride anion and two water mol-ecules in the asymmetric unit form a hydrogen-bonded network connected to the complex mol-ecules in the crystal via the NH amine groups, forming chains along [100].

Crystal structure of (S)-5,7-diphenyl-4,7-di-hydro-tetra-zolo[1,5-a]pyrimidine

The title compound, C16H13N5, was synthesized by coupling amino-tetra-zole with chalcone in the presence of an amine organocatalyst derived from chincona alkaloid. There are two mol-ecules, A and B, in the asymmetric unit. In mol-ecule A, the dihedral angles between the partly hydrogenated pyrimidine ring system (r.m.s. deviation = 0.056 Å) and the sp (2)- and sp (3)-bonded phenyl groups are 33.32 (11) and 86.53 (11)°, respectively. The equivalent data for mol-ecule B are 0.049 Å, and 27.05 (10) and 85.27 (11)°, respectively. In the crystal, A+B dimers linked by pairs of N-H⋯N hydrogen bonds generate R 2 (2)(8) loops. The dimers are linked by aromatic π-π stacking inter-actions [shortest centroid-centroid separation = 3.5367 (15) Å], which results in a three-dimensional network.

The crystal structures of three clozapinium salts: different mol-ecular configurations, and supra-molecular assembly in one, two and three dimensions

The structures of three salts derived from clozapine, 8-chloro-11-(4-methyl-piperazin-1-yl)-5H-dibenzo[b,e][1,4]diazepine, are reported, namely, clo-za-pin-ium 3,5-di-nitro-benzoate dimethyl sulfoxide monosolvate, C18H20ClN4 (+)·C7H3N2O6 (-)·C2H6OS, (I), where the dimethyl sulfoxide component is disordered over two sets of atomic sites having occupancies 0.627 (2) and 0.373 (2); clo-za-pin-ium hydrogen maleate 0.21-hydrate, C18H20ClN4 (+)·C4H3O4 (-)·0.21H2O, (II), and clozapinium 2-hy-droxy-benzoate, C18H20ClN4 (+)·C7H5O3 (-), (III). In all three salts, the protonation site is the methyl-ated N atom of the piperazine ring, and the dimensions and conformations of the fused tricyclic system are very similar. However, differences are apparent in the piperazine component: in both compounds (II) and (III), the unprotonated N atom of this ring has a pyramidal geometry, but in compound (I) this atom has a planar geometry. In compound (III), both N-substituents in this ring occupy equatorial sites, but in compound (II) the fused tricyclic system occupies an axial site of the piperazine ring. The independent components of compound (I) are linked within the selected asymmetric unit by a combination of N-H⋯O and C-H⋯O hydrogen bonds, and these hydrogen-bonded aggregates are linked into chains by an aromatic π-π stacking inter-action. In compound (II), the components are linked into sheets by a combination of O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds, and in compound (III), a combination of N-H⋯O, C-H⋯O and C-H⋯N hydrogen bonds links the components into a three-dimensional framework structure. Comparisons are made with some similar compounds.

Crystal structures of the water and acetone monosolvates of bis-[4'-(pyridin-4-yl)-2,2':6',2''-terpyridine]-manganese(II) bis-(hexa-fluorido-phosphate)

The crystal structures of bis-[4'-(pyridin-4-yl)-2,2':6',2''-terpyridine]-man-gan-ese(II) bis-(hexa-fluorido-phosphate) monohydrate, [Mn(C20H14N4)2](PF6)2·H2O, (1), and bis-[4'-(pyridin-4-yl)-2,2':6',2''-terpyridine]-manganese(II) bis(hexa-fluorido-phosphate) acetone monosolvate, (2), [Mn(C20H14N4)2](PF6)2·CH3COCH3, are described. At 150 K, (1) and (2) have monoclinic (P21/c) and ortho-rhom-bic (C2221) symmetries, respectively. Both structures exhibit octahedrally coordinated Mn(II) atoms and disorder. They display weak inter-actions, such as C-H⋯F, C-H⋯N, C-H⋯π, F⋯π and π-π. The twofold rotation axis in the molecule of (2) is coincident with a twofold rotation axis of the crystal.

Crystal structures of {[Cu(Lpn)2][Fe(CN)5(NO)]·H2O} n and {[Cu(Lpn)2]3[Cr(CN)6]2·5H2O} n [where Lpn = (R)-propane-1,2-di-amine]: two heterometallic chiral cyanide-bridged coordination polymers

The title compounds, catena-poly[[[bis-[(R)-propane-1,2-di-amine-κ(2) N,N']copper(II)]-μ-cyanido-κ(2) N:C-[tris-(cyanido-κC)(nitroso-κN)iron(III)]-μ-cyanido-κ(2) C:N] monohydrate], {[Cu(Lpn)2][Fe(CN)5(NO)]·H2O} n , (I), and poly[[hexa-μ-cyanido-κ(12) C:N-hexa-cyanido-κ(6) C-hexa-kis-[(R)-propane-1,2-di-amine-κ(2) N,N']dichromium(III)tricopper(II)] penta-hydrate], {[Cu(Lpn)2]3[Cr(CN)6]2·5H2O} n , (II) [where Lpn = (R)-propane-1,2-di-amine, C3H10N2], are new chiral cyanide-bridged bimetallic coordination polymers. The asymmetric unit of compound (I) is composed of two independent cation-anion units of {[Cu(Lpn)2][Fe(CN)5)(NO)]} and two water mol-ecules. The Fe(III) atoms have distorted octa-hedral geometries, while the Cu(II) atoms can be considered to be penta-coordinate. In the crystal, however, the units align to form zigzag cyanide-bridged chains propagating along [101]. Hence, the Cu(II) atoms have distorted octa-hedral coordination spheres with extremely long semicoordination Cu-N(cyanido) bridging bonds. The chains are linked by O-H⋯N and N-H⋯N hydrogen bonds, forming two-dimensional networks parallel to (010), and the networks are linked via N-H⋯O and N-H⋯N hydrogen bonds, forming a three-dimensional framework. Compound (II) is a two-dimensional cyanide-bridged coordination polymer. The asymmetric unit is composed of two chiral {[Cu(Lpn)2][Cr(CN)6]}(-) anions bridged by a chiral [Cu(Lpn)2](2+) cation and five water mol-ecules of crystallization. Both the Cr(III) atoms and the central Cu(II) atom have distorted octa-hedral geometries. The coordination spheres of the outer Cu(II) atoms of the asymmetric unit can be considered to be penta-coordinate. In the crystal, these units are bridged by long semicoordination Cu-N(cyanide) bridging bonds forming a two-dimensional network, hence these Cu(II) atoms now have distorted octa-hedral geometries. The networks, which lie parallel to (10-1), are linked via O-H⋯O, O-H⋯N, N-H⋯O and N-H⋯N hydrogen bonds involving all five non-coordinating water mol-ecules, the cyanide N atoms and the NH2 groups of the Lpn ligands, forming a three-dimensional framework.

An investigation of polyhedral deformation in two mixed-metal diarsenates: SrZnAs₂O₇ and BaCuAs₂O₇

Two isostructural diarsenates, SrZnAs2O7 (strontium zinc diarsenate), (I), and BaCuAs2O7 [barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharing M2O5 (M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7 group shares its five corners with five different M2O5 square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinated M1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of the M1O9, M2O5 and As2O7 groups of known isostructural diarsenates, adopting the general formula M1(II)M2(II)As2O7 (M1(II) = Sr, Ba, Pb; M2(II) = Mg, Co, Cu, Zn) and crystallizing in the space group P2₁/n, are presented and discussed.

Crystal structure of (E)-2-[(2-hy-droxy-4-meth-oxy-phen-yl)(phen-yl)methyl-idene]-N-phenyl-hydrazine-1-carboxamide

The title compound, C21H19N3O3, has an E conformation about the azomethine double bond. The central moiety of the hydrazinecarboxamide moiety [-N-N-C(=O)-N-] has an almost coplanar arrangement [maximum deviation for the C atom = 0.010 (2) Å]. This central moiety is flanked by three aromatic rings and its mean plane makes dihedral angles of 24.7 (1), 72.91 (12) and 34.26 (11) Å, respectively, with the phenolic ring, the phenyl ring attached to the same C atom as the phenolic ring, and the phenyl-hydrazine ring. The adjacent phenolic and phenyl rings are twisted away from each other to reduce steric hindrance and make a dihedral angle of 80.59 (12)°. The phenolic and phenyl-hydrazine rings are inclined to one another by 28.89 (11)°. The rigidity of the mol-ecule is increased by an intra-molecular O-H⋯N hydrogen bond involving the phenolic hydrogen and the azomethine N atom. In the crystal, the carbonyl O atom forms bifurcated hydrogen bonds with the two NH atoms of the hydrazinic group, leading to the formation of chains propagating along [001]. Within the chains there are also C-H⋯O hydrogen bonds present. The chains are linked via C=O⋯π [3.4316 (18) Å] and parallel slipped π-π inter-actions, involving inversion-related benzene rings [centroid-centroid distance = 3.8850 (14) Å; inter-planar distance = 3.3895 (10) Å; slippage = 1.899 Å], forming sheets lying parallel to (100).

Crystal structure of tris-[μ2-bis-(di-phenyl-phosphan-yl)methane-κ(2) P:P']di-μ3-bromido-tris-ilver(I) bromide-N,N'-phenyl-thio-urea (1/1)

The title complex, [Ag3Br2(C25H22P2)3]Br·C7H8N2S, comprises a trinuclear [Ag3Br2(C25H22P2)3](+) unit, a Br(-) anion and one N,N'-di-methyl-thio-urea mol-ecule (ptu). Three Ag(I) ions are linked via two μ3-bridging Br atoms, leading to a distorted triangular bipyramid with an Ag⋯Ag separation range of 3.1046 (6)-3.3556 (6) Å. The triangular Ag3 arrangement is stabilized by six P atoms from three chelating bis-(di-phenyl-phosphan-yl)methane (dppm) ligands. The Ag(I) ion presents a distorted tetra-hedral coordination geometry. In the crystal, the bromide anion is connected to the ptu mol-ecule through N-H⋯Br hydrogen bonds [graph-set motif R 2 (1)(6)]. Each bromide/ptu aggregate links the complex ion via C-H⋯S and C-H⋯Br hydrogen bonds, leading to the formation of a three-dimensional network. Two phenyl rings from two dppm ligands were modelled as disordered over two sites.

Redetermination and absolute configuration of berkeleydione

The crystal structure of the title compound, berkeleydione [systematic name; (5aS,7R,9S,11R,11aS)-methyl 9-hy-droxy-1,1,5,7,9,11a-hexa-methyl-14-methyl-idene-3,8,10-trioxo-1,3,4,5a,6,7,8,9,10,11,11a,12-dodeca-hydro-7,11-methano-cycloocta-[4,5]cyclo-hepta-[1,2-c]pyran-11-carboxyl-ate], C26H32O7, has been reported previously [Stierle et al. (2004 ▶). Org. Lett. 6, 1049-1052]. However, the absolute configuration could not be determined from the data collected with Mo Kα radiation and has now been determined by refinement of the Flack parameter with data collected using Cu Kα radiation. It is in agreement with the previous circular dichroism assignment, and the crystal packing is similar to that described previously.

Crystal structure of ethyl N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-di-hydro-1H-pyrazol-4-yl)carbamate

In the title compound, C14H17N3O3, the dihedral angle between the benzene ring and the five-membered di-hydro-pyrazole ring is 52.26 (9)°. The ethyl ester group is approximately planar (r.m.s. deviation 0.0568 Å) and subtends an angle 67.73 (8)° to the pyrazole ring. In the crystal, molecules are linked by pairs of N-H⋯O hydrogen bonds, forming inversion dimers with an R 2 (2)(10) ring motif. Weaker C-H⋯O contacts link these dimers into a three-dimensional network of mol-ecules stacked along the a-axis direction. Offset π-π stacking inter-actions between the benzene rings [centroid-to-centroid distance = 3.8832 (12) Å] further stabilize the crystal packing.