2

Crystallographic snapshots of the EF-hand protein MCFD2 complexed with the intracellular lectin ERGIC-53 involved in glycoprotein transport

The transmembrane intracellular lectin ER–Golgi intermediate compartment protein 53 (ERGIC-53) and the soluble EF-hand multiple coagulation factor deficiency protein 2 (MCFD2) form a complex that functions as a cargo receptor, trafficking various glycoproteins between the endoplasmic reticulum (ER) and the Golgi apparatus. It has been demonstrated that the carbohydrate-recognition domain (CRD) of ERGIC-53 (ERGIC-53CRD) interacts with N-linked glycans on cargo glycoproteins, whereas MCFD2 recognizes polypeptide segments of cargo glycoproteins. Crystal structures of ERGIC-53CRD complexed with MCFD2 and mannosyl oligosaccharides have revealed protein–protein and protein–sugar binding modes. In contrast, the polypeptide-recognition mechanism of MCFD2 remains largely unknown. Here, a 1.60 Å resolution crystal structure of the ERGIC-53CRD–MCFD2 complex is reported, along with three other crystal forms. Comparison of these structures with those previously reported reveal that MCFD2, but not ERGIC-53–CRD, exhibits significant conformational plasticity that may be relevant to its accommodation of various polypeptide ligands.




2

Structure of a single-chain H2A/H2B dimer

Chromatin is the complex assembly of nucleic acids and proteins that makes up the physiological form of the eukaryotic genome. The nucleosome is the fundamental repeating unit of chromatin, and is composed of ∼147 bp of DNA wrapped around a histone octamer formed by two copies of each core histone: H2A, H2B, H3 and H4. Prior to nucleosome assembly, and during histone eviction, histones are typically assembled into soluble H2A/H2B dimers and H3/H4 dimers and tetramers. A multitude of factors interact with soluble histone dimers and tetramers, including chaperones, importins, histone-modifying enzymes and chromatin-remodeling enzymes. It is still unclear how many of these proteins recognize soluble histones; therefore, there is a need for new structural tools to study non-nucleosomal histones. Here, a single-chain, tailless Xenopus H2A/H2B dimer was created by directly fusing the C-terminus of H2B to the N-terminus of H2A. It is shown that this construct (termed scH2BH2A) is readily expressed in bacteria and can be purified under non-denaturing conditions. A 1.31 Å resolution crystal structure of scH2BH2A shows that it adopts a conformation that is nearly identical to that of nucleosomal H2A/H2B. This new tool is likely to facilitate future structural studies of many H2A/H2B-interacting proteins.




2

Chirality in Biological Nanospaces: Reactions in Active Sites. By Nilashis Nandi. Pp. 209. CRC Press, 2011. Price £79.99. ISBN 9781439840023.




2

Solution structure and assembly of β-amylase 2 from Arabidopsis thaliana

Solution structure of β-amylase 2 from Arabidopsis thaliana shows the role of the conserved N-terminus in enzyme tetramer formation.




2

Structure of Thermococcus litoralis Δ1-pyrroline-2-carboxylate reductase in complex with NADH and L-proline

The paper reports the structure of a Δ1-pyrroline-2-carboxylate reductase from the archaeon Thermococcus litoralis, a key enzyme involved in the second step of trans-4-Hydroxy-L-proline metabolism, conserved in archaea, bacteria and humans.




2

2,3-Di­chloro-3',4'-di­hydroxy­biphen­yl

The title compound [systematic name: 4-(2,3-Dichlorophenyl)benzene-1,2-diol], C12H8Cl2O2, is a putative di­hydroxy­lated metabolite of 2,3-di­chloro­biphenyl (PCB 5). The title structure displays intra­molecular O—H⋯O hydrogen bonding, and the π–π stacking distance between inversion-related chlorinated benzene rings of the title compound is 3.371 (3) Å. The dihedral angle between two benzene rings is 59.39 (8)°.




2

1,3-Bis{[(2,6-di­methyl­phen­yl)sulfan­yl]meth­yl}benzene

The structure of the title compound, C24H26S2, an example of a pincer ligand with an SCS-chelation motif, illustrates the steric effects of the methyl groups in the thio­phenyl rings at the 2- and 6-positions, forcing a dissimilar spatial orientation of the thio­phenyl rings relative to the central aryl group [dihedral angles = 33.58 (7) and 40.49 (7)°]. In the crystal, weak S⋯S contacts [3.4009 (7) Å] link the mol­ecules into inversion dimers.




2

6-Amino-2-iminiumyl-4-oxo-1,2,3,4-tetra­hydro­pyrimidin-5-aminium sulfate monohydrate

The title compound, C4H9N5O2+·SO42−·H2O, is the monohydrate of the commercially available compound `C4H7N5O·H2SO4·xH2O'. It is obtained by reprecipitation of C4H7N5O·H2SO4·xH2O from dilute sodium hydroxide solution with dilute sulfuric acid. The crystal structure of anhydrous 2,4,5-tri­amino-1,6-di­hydro­pyrimidin-6-one sulfate is known, although called by the authors 5-amminium-6-amino-isocytosinium sulfate [Bieri et al. (1993). Private communication (refcode HACDEU). CCDC, Cambridge, England]. In the structure, the sulfate group is deprotonated, whereas one of the amino groups is protonated (R2C—NH3+) and one is rearranged to a protonated imine group (R2C=NH2+). This arrangement is very similar to the known crystal structure of the anhydrate. Several tautomeric forms of the investigated mol­ecule are possible, which leads to questionable proton attributions. The measured data allowed the location of all hydrogen atoms from the residual electron density. In the crystal, ions and water mol­ecules are linked into a three-dimensional network by N—H⋯O and O—H⋯O hydrogen bonds.




2

Di­chlorido­{N,N,N'-trimethyl-N'-(1H-pyrazol-1-yl-κN2)meth­yl]ethane-1,2-di­amine-κ2N,N'}copper(II) methanol monosolvate

In the title compound, [CuCl2(C9H18N4)]·CH3OH, the central CuII ion is coordinated by three N atoms from the pyrazole derivative ligand and two chloride co-ligands. The coordination geometry around the CuII ion is distorted trigonal–bipyramidal. In the crystal, the mol­ecules are linked by C—H⋯O, C—H⋯Cl and O—H⋯Cl hydrogen bonds, forming a three-dimensional framework with the lattice solvent mol­ecule.




2

Redetermination of the crystal structure of BaTeO3(H2O), including the localization of the hydrogen atoms

The redetermination of the crystal structure of barium oxidotellurate(IV) monohydrate allowed the localization of the hydrogen atoms that were not determined in the previous study [Nielsen, Hazell & Rasmussen (1971). Acta Chem. Scand. 25, 3037–3042], thus making an unambiguous assignment of the hydrogen-bonding scheme possible. The crystal structure shows a layered arrangement parallel to (001), consisting of edge-sharing [BaO6(H2O)] polyhedra and flanked by isolated [TeO3] trigonal pyramids on the top and bottom. O—H⋯O hydrogen bonds of medium strength link adjacent layers along [001].




2

2-Amino-6-chloro­pyridine–glutaric acid (1/1)

In the title 1:1 co-crystal [systematic name: 6-chloro­pyridin-2-amine–penta­nedioic acid (1/1)], C5H5ClN2·C5H8O4, the pyridine ring is essentially planar, with a maximum deviation of 0.003 (1) Å. The base and acid mol­ecules are linked via N—H⋯O and O—H⋯N hydrogen bonds, while inversion-related acid mol­ecules are linked via pairs of O—H⋯O hydrogen bonds. These inter­actions together with a C—H⋯O hydrogen bond connect the two components, forming (001) sheets.




2

Crystal structure of bis­(benzoato-κO)[5,15-diphenyl-10,20-bis­(pyridin-4-yl)porphyrinato-κ4N,N',N'',N''']tin(IV)

In the crystal structure of the title compound, [Sn(C42H26N6)(C7H5O2)2], the SnIV ion is located on a crystallographic inversion centre and is octa­hedrally coordinated with an N4O2 set. Four N atoms of the porphyrin ring form the equatorial plane while the axial positions are occupied by two O atoms from benzoate anions. The molecular packing of the title complex involves non-classical hydrogen bonds of the types C—H⋯O and C—H⋯N, leading to a three-dimensional network structure.




2

(E)-4-Iodo-2-[(phenyl­imino)­meth­yl]phenol

The title compound, C13H10INO, is not planar as the dihedral angle between the planes of the two aryl rings is 44.5 (9)°. The configuration about the central C=N bond is E, and there is an intra­molecular O—H⋯N hydrogen bond which generates an S(6) ring. The mol­ecular packing is stabilized by weak C—H⋯π inter­actions. The structure was refined as a two-component inversion twin.




2

Bis[benzyl 2-(heptan-4-yl­idene)hydrazine-1-carboxyl­ate]bis­(thio­cyanato)­cobalt(II)

The title compound, [Co(NCS)2(C15H22N2O2)2] or C32H44CoN6O4S2, was prepared from cobalt(II) nitrate, benzyl carbazate and ammonium thio­cyanate in the presence of 4-hepta­none. The compound crystallizes with two centrosymmetric complexes in which the cobalt(II) atoms have a trans-CoO2N4 octa­hedral coordination geometry. In the crystal, N—H⋯S, C—H⋯S and C—H⋯.π contacts stack the complex mol­ecules along the b-axis direction.




2

Di­bromido­[N-(1-di­ethyl­amino-1-oxo-3-phenyl­propan-2-yl)-N'-(pyridin-2-yl)imidazol-2-yl­idene]palladium(II) di­chloro­methane monosolvate

In the mol­ecule of the title N,N'-disubstituted imidazol-2-yl­idene palladium(II) complex, [PdBr2(C21H24N4O)]·CH2Cl2, the palladium(II) atom adopts a slightly distorted square-planar coordination (r.m.s. deviation = 0.0145 Å), and the five-membered chelate ring is almost planar [maximum displacement = 0.015 (8) Å]. The mol­ecular conformation is enforced by intra­molecular C—H⋯Br hydrogen bonds. In the crystal, complex mol­ecules and di­chloro­methane mol­ecules are linked into a three-dimensional network by C—H⋯O and C—H⋯Br hydrogen bonds.




2

Poly[di­aqua­[μ4-2-(carboxyl­atometh­oxy)benzoato][μ2-2-(carboxyl­atometh­oxy)benzoato]dicad­mium(II)]

In the title compound, [Cd2(C9H6O5)2(H2O)2]n, the crystallographically distinct CdII cations are coordinated in penta­gonal–bipyramidal and octa­hedral fashions. The 2-(carb­oxy­meth­oxy)benzoate (cmb) ligands connect the Cd atoms into [Cd2(cmb)2(H2O)2)]n coordination polymer ribbons that are oriented along the a-axis direction. Supra­molecular layers are formed parallel to (01overline{1}) by O—H⋯O hydrogen bonding between the ribbons. The supra­molecular three-dimensional crystal structure of the title compound is then constructed by π–π stacking inter­actions with a centroid–centroid distance of 3.622 (2) Å between cmb ligands in adjacent layer motifs.




2

Ethyl 4-(4-chloro-3-fluoro­phen­yl)-6-methyl-2-sulfanyl­idene-1,2,3,4-tetra­hydro­pyrimidine-5-carboxyl­ate

In the title compound, C14H14ClFN2O2S, the di­hydro­pyrimidine ring adopts a shallow-boat conformation and subtends a dihedral angle of 81.91 (17)° with the phenyl ring. In the crystal, N—H⋯O, N—H⋯S and C—H⋯F hydrogen bonds and C—H⋯π inter­actions are found.




2

N-[(Pyridin-2-yl)meth­yl]thio­phene-2-carboxamide

In the title compound, C11H10N2OS, the dihedral angle between the thio­phene and pyridine rings is 77.79 (8)°. In the crystal, inversion dimers linked by pairs of N—H⋯N hydrogen bonds generate R22(10) loops. The dimers are reinforced by pairs of C—H⋯N inter­actions and C—H⋯O inter­actions link the dimers into [010] chains.




2

Bis(2-methyl­lactato)borate tetra­hydrate

The asymmetric unit of the title compound (systematic name: 3,3,8,8-tetra­methyl-1,4,6,9-tetra­oxa-λ4-bora­spiro­[4.4]nonane-2,7-dione tetra­hydrate), C8H12BO6·4H2O, consists of half a bis­(2-methyl­lactato)borate mol­ecule and two water mol­ecules of solvation. In the crystal, O—H⋯O hydrogen bonds link the components into a three-dimensional network.




2

(2S,3S,4R,4a'R,5R,5a'R,11a'R,12'S,12a'R)-5-(Acet­oxy­meth­yl)-2',2',10',10'-tetra­methyl­octa­hydro-3H,8'H-spiro­[furan-2,7'-[1,3]dioxino[4',5':5,6]pyrano[3,2-d][1,3,6]trioxocine]-3,4,12'-triyl tri­a

While the crystal structure analysis of the title compound, C26H38O15, a synthetic derivative of sucrose, was originally reported 40 years ago [Drew et al. (1979). Carbohydr. Res. 71, 35–42], the present work has allowed for the determination of its absolute configuration through the application of resonant scattering techniques.




2

1,2,4,5-Tetra­chloro-3,6-di­iodo­benzene benzene monosolvate

The title compound, C6Cl4I2·C6H6, crystallizes from benzene solution as cube-shaped crystals in the triclinic space group Poverline{1} with Z = 1. The asymmetric unit of the crystal structure contains one half of each mol­ecule. In the crystal, the benzene ring is almost orthogonal to the perhalo­benzene ring and the mol­ecules are linked by C—I⋯π inter­actions, with a close contact between the iodine atom and the benzene ring of 3.412 (1) Å.




2

catena-Poly[[di­aqua­cadmium(II)]-μ2-3-(4-carboxyl­atophen­yl)propionato]

In the title compound, [Cd(C10H8O4)(H2O)2)]n, the CdII cation is coordinated in a distorted trigonal–prismatic fashion. 3-(4-Carb­oxy­phen­yl)propionate (cpp) ligands connect the CdII cations into zigzag [Cd(cpp)(H2O)2)]n coordination polymer chains, which are oriented parallel to [101]. The chains aggregate into supra­molecular layers oriented parallel to (10overline{1}) by means of O—H⋯O hydrogen bonding between bound water mol­ecules and ligating cpp carboxyl­ate O atoms. The layers stack in an ABAB pattern along [100] via other O—H⋯O hydrogen-bonding mechanisms also involving the bound water mol­ecules. The crystal studied was an inversion twin.




2

Di-μ-acetato-bis­{[3-benzyl-1-(2,4,6-tri­methyl­phen­yl)imidazol-2-ylidene]silver(I)}

The title compound, [Ag2(C2H3O2)2(C19H20N2)2] (2), was readily synthesized by treatment of 3-benzyl-1-(2,4,6-tri­methyl­phen­yl)imidazolium chloride with silver acetate. The solution structure of the complex was analyzed by NMR spectroscopy, while the solid-state structure was confirmed by single-crystal X-ray diffraction studies. Compound 2 crystallizes in the triclinic space group Poverline{1}, with a silver-to-carbene bond length (Ag—CNHC) of 2.084 (3) Å. The mol­ecule resides on an inversion center, so that only half of the mol­ecule is crystallographically unique. The planes defined by the two imidazole rings are parallel to each other, but not coplanar [inter­planar distance is 0.662 (19) Å]. The dihedral angles between the imidazole ring and the benzyl and mesityl rings are 77.87 (12) and 72.86 (11)°, respectively. The crystal structure features π–π stacking inter­actions between the benzylic groups of inversion-related (−x + 1, −y + 1, −z + 1) mol­ecules and C—H⋯π inter­actions.




2

trans-Bis(dimethyl sulfoxide-κO)bis­(3-nitro­benzo­hydroxamato-κ2O,O')zinc(II)

Single crystals of the title complex, [Zn(C7H5N2O4)2(C2H6OS)2] or [Zn(NBZH)2(DMSO)2], were isolated from a dimethyl sulfoxide (DMSO) solution containing [Zn(NBZH)2]·2H2O (NBZH = 3-nitro­benzo­hydroxamate anion). The asymmetric unit comprises of one O,O'-chelating NBZH anion, one O-bound DMSO ligand and one zinc(II) cation localized on an inversion centre. The three-dimensional crystal packing includes N—H⋯O and C—H⋯O hydrogen bonding, as well as O⋯H and H⋯H contacts identified by Hirshfeld isosurface analysis.




2

(2,2-Bi­pyridine-κ2N,N')chlorido­[η6-1-methyl-4-(propan-2-yl)benzene]­ruthenium(II) tetra­phenyl­borate

The title complex, [RuCl(C10H14)(C10H8N2)](C24H20B), has monoclinic (P21) symmetry at 100 K. It was prepared by the reaction of the di­chlor­ido[1-methyl-4-(propan-2-yl)benzene]­ruthenium(II) dimer with 2,2'-bi­pyridine, followed by the addition of ammonium tetra­phenyl­borate. The 1-methyl-4-(propan-2-yl)benzene group, the 2,2'-bi­pyridine unit and a chloride ion coordinate the ruthenium(II) atom, with the 1-methyl-4-(propan-2-yl)benzene ring and bi­pyridine moieties trans to each other. In the crystal, the complex cations are linked by C—H⋯Cl hydrogen bonds, forming chains parallel to [010]. These chains are linked by a number of C—H⋯π inter­actions, involving the phenyl rings of the tetra­phenyl­borate anion and a pyridine ring of the bpy ligand, resulting in the formation of layers parallel to (10overline{1}).




2

(1Z,2Z)-1,2-Bis{2-[3,5-bis­(tri­fluoro­meth­yl)phen­yl]hydrazinyl­idene}-1,2-bis­(4-meth­oxy­phen­yl)ethane including an unknown solvate

The complete mol­ecule of the title compound, C32H22F12N4O2, is generated by a crystallographic twofold axis aligned parallel to [010]. The F atoms of one of the CF3 groups are disordered over three orientations in a 0.6: 0.2: 0.2 ratio. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds, forming zigzag chains propagating along the a-axis direction. In addition, weak C—H⋯O and C—H⋯F bonds are observed. The contribution of the disordered solvent to the scattering was removed using the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9–18] of PLATON. The solvent contribution is not included in the reported mol­ecular weight and density.




2

8,13-Diisopropyl-10,11-dimethyl-bis([1,3]dioxolo[4',5':6,7]naphtho)­[1,2-d;2,1-f][1,3]dioxepine

The title compound, C31H30O6, was obtained by protecting the six hy­droxy groups of apogossypol by acetalization with di­chloro­methane. The mol­ecule has a bridging dioxepine unit which hinders the rotation around the 2,2'-inter­naphthyl bond. The dihedral angle between the naphthyl units is 55.73 (3)°. In the crystal, very weak C—H⋯O inter­actions may help to consolidate the packing.




2

(S)-1-(Benzyl­selan­yl)-3-phenyl­propan-2-amine

In the title compound, C16H19NSe, the dihedral angle between the benzene rings is 66.49 (12) and a weak intra­molecular N—H⋯Se hydrogen bond generates an S(6) ring. In the crystal, weak N—H⋯N hydrogen bonds link the mol­ecules into [100] chains.




2

1-(2-Amino-5-chloro­phen­yl)-2,2,2-tri­fluoro­ethan-1-one

In the title compound, C8H5ClF3NO, the F—C—C=O grouping shows a syn conformation [torsion angle = 1.1 (3)°] and an intra­molecular N—H⋯O hydrogen bond generates an S(6) ring. In the crystal, N—H⋯F and N—H⋯O hydrogen bonds link the mol­ecules into [010] chains.




2

(Pyridine-2,6-di­carboxyl­ato-κ3O,N,O')(2,2':6',2''- terpyridine-κ3N,N',N'')nickel(II) di­methyl­formamide monosolvate monohydrate

In the title complex, [Ni(C7H3NO4)(C15H11N3)]·C3H7NO·H2O, the NiII ion is six-coordinated within an octa­hedral geometry defined by three N atoms of the 2,2':6',2''-terpyridine ligand, and two O atoms and the N atom of the pyridine-2,6-di­carboxyl­ate di-anion. In the crystal, the complex mol­ecules are stacked in columns parallel to the a axis being connected by π–π stacking [closest inter-centroid separation between pyridyl rings = 3.669 (3) Å]. The connections between columns and solvent mol­ecules to sustain a three-dimensional architecture are of the type water-O—H⋯O(carbon­yl) and pyridyl-, methyl-C—H⋯O(carbon­yl).




2

3-(2,5-Di­chloro­thio­phen-3-yl)-5-(2,4-di­meth­oxy­phen­yl)-1-methyl-4,5-di­hydro-1H-pyrazole

In the title compound, C16H16Cl2N2O2S, the pyrazole ring has an envelope conformation with the C atom bearing the phenyl ring being the flap. The dihedral angles between the central pyrazole ring (all atoms) and pendant thio­phene and phenyl rings are 2.00 (14) and 81.49 (12)°, respectively. In the crystal, weak C—H⋯O, Cl⋯π and π–π stacking inter­actions link the mol­ecules into a three-dimensional network.




2

Bis(μ2-4-nitro­phenolato)bis­(4-nitro­phenolato)di-μ3-oxido-octaphenyltetra­tin chloro­form sesquisolvate [+ solvate]: a tetra­nuclear stannoxane

The title tetra­nuclear stannoxane, [Sn4(C6H5)8(C6H4NO3)4O2]·1.5CHCl3·solvent, crystallized with two independent complex mol­ecules, A and B, in the asymmetric unit together with 1.5 mol­ecules of chloro­form. There is also a region of disordered electron density, which was corrected for using the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9–18]. The oxo-tin core of each complex is in a planar `ladder' arrangement and each Sn atom is fivefold SnO3C2 coordinated, with one tin centre having an almost perfect square-pyramidal coordination geometry, while the other three Sn centres have distorted shapes. In the crystal, the complex mol­ecules are arranged in layers, composed of A or B complexes, lying parallel to the bc plane. The complex mol­ecules are linked by a number of C—H⋯O hydrogen bonds within the layers and between the layers, forming a supra­molecular three-dimensional structure.




2

5-Chloro-2-ferrocenylbenzo[d]oxazole

The asymmetric unit of the title compound, [Fe(C5H5)(C12H7ClNO)], consists of one ferrocenyl group bonded to chloro­benzo[d]oxazole. The conformation of the ferrocenyl moiety is slightly away from eclipsed. The bond angles between the 5-chloro-benzoxazole and ferrocenyl fragments are N—C—C = 127.4 (7)° and O—C—C = 116.8 (7)°. The benzo[d]oxazole ring is planar (r.m.s. deviation = 0.0042 Å) and makes an angle of 11.3 (4)° with the cyclo­penta­dienyl ring attached to it. The crystal packing is characterized by inter­molecular π–π contacts, resulting in chain formation along the b-axis direction. The centroid-to-centroid distance between the six- and five-membered rings is 3.650 (5) Å. Together with a C—H⋯π inter­action, these inter­molecular contacts form laminar arrays along the ac plane.




2

6-Nitro-1,3-benzoxazole-2(3H)-thione

In the title compound, C7H4N2O3S, the dihedral angle between the fused ring system (r.m.s. deviation = 0.008 Å) and the nitro group at the 6-position is 7.3 (2)°. In the crystal, bifurcated N—H⋯(O,O) hydrogen bonds link the mol­ecules into [010] chains. The chains are cross-linked by π–π stacking inter­actions to form (001) sheets.




2

Crystal structure of a salt with a protonated sugar cation and a cobalt(II) complex anion: (GlcN–H, K)[Co(NCS)4]·2H2O

The title compound, d-(+)-glucosa­mmonium potassium tetra­thio­cyanato­cobaltate(II) dihydrate, K(C6H14NO5)[Co(NCS)4]·2H2O or (GlcNH)(K)[Co(NCS)4]·2H2O, has been obtained as a side product of an incomplete salt metathesis reaction of d-(+)-glucosa­mine hydro­chloride (GlcN·HCl) and K2[Co(NCS)4]. The asymmetric unit contains a d-(+)-glucos­ammonium cation, a potassium cation, a tetra­iso­thio­cyanato­cobalt(II) complex anion and two water mol­ecules. The water mol­ecules coordinate to the potassium cation, which is further coordinated via three short K+⋯SCN− contacts involving three [Co(NCS)4]2− complex anions and via three O atoms of two d-(+)-glucosa­mmonium cations, leading to an overall eightfold coordination around the potassium cation. Hydrogen-bonding inter­actions between the building blocks consolidate the three-dimensional arrangement.




2

5,10-Di­hydro­indeno­[2,1-a]indene

The title compound, C16H12, crystallizes with four half mol­ecules in the asymmetric unit, each of which is located on a crystallographic centre of inversion. The mol­ecules are essentially planar. The crystal studied was a non-merohedral twin.




2

Bis(μ2-benzoato-κ2O,O')bis­(benzoato-κO)bis(ethanol-κO)bis­(μ3-hydroxido)hexa­kis­(μ-pyrazol­ato-κ2N,N')hexa­copper(II) ethanol disolvate

Trinuclear copper–pyrazolate entities are present in various Cu-based enzymes and nanojar supra­molecular arrangements. The reaction of copper(II) chloride with pyrazole (pzH) and sodium benzoate (benzNa) assisted by microwave radiation afforded a neutral centrosymmetric hexa­nuclear copper(II) complex, [Cu6(C7H5O2)4(OH)2(C3H3N2)6(C2H5OH)2]·2C2H5OH. Half a mol­ecule is present in the asymmetric unit that comprises a [Cu3(μ3-OH)(pz)3]2+ core with the copper(II) atoms arranged in an irregular triangle. The three copper(II) atoms are bridged by an O atom of the central hydroxyl group and by three bridging pyrazolate ligands on each of the sides. The carboxyl­ate groups show a chelating mode to one and a bridging syn,syn mode to the other two CuII atoms. The coordination environment of one CuII atom is square-planar while it is distorted square-pyramidal for the other two. Two ethanol mol­ecules are present in the asymmetric unit, one binding to one of the CuII atoms, one as a solvent mol­ecule. In the crystal, stabilization arises from inter­molecular O—H⋯O hydrogen-bonding inter­actions.




2

3-(3,5-Di­chloro­phen­yl)benzene-1,2-diol

The title structure, C12H8Cl2O2, is a putative metabolite of 3,5-di­chloro­biphenyl (PCB 14). The dihedral angle between the two benzene rings of the title compounds is 58.86 (4)°. In the crystal, it displays intra- and inter­molecular O—H⋯O hydrogen bonding and inter­molecular O—H⋯Cl hydrogen⋯chlorine inter­actions. The inter­molecular inter­actions form a two-dimensional network parallel to (010).




2

[SP-4-2]-(Aceto­nitrile-κN)chlorido­[2-(4,6-di­phenyl­pyridin-2-yl)phenyl-κ2C1,N]platinum(II)

The synthesis and crystal structure of the title PtII complex, [Pt(C23H16N)Cl(CH3CN)], based on the C,N-chelating 2,4,6-tri­phenyl­pyridine as the primary ligand, is described. The central PtII atom is in a distorted square-planar coordination environment. In the crystal, mol­ecules are arranged via a metallophilic inter­action between platinum atoms with a Pt⋯Pt contact of 7.052 (2) Å. In addition, a π–π inter­action occurs.




2

1:1 Co-crystal of 3-ethyl-4-methyl-3-pyrrolin-2-one and 3-ethyl-4-methyl-3-pyrroline-2,5-dione

Crystallization from a 20-year-old commercial source of 3-ethyl-4-methyl-3-pyrrolin-2-one afforded 1:1 co-crystals of this compound (C7H11NO) with its oxidized derivative, 3-ethyl-4-methyl-3-pyrroline-2,5-dione (C7H9NO2). The compound crystallizes in the space group Poverline{1}, with two mol­ecules of each species in the asymmetric unit. These four mol­ecules form a hydrogen-bonded tetra­mer with a dimer of 3-ethyl-4-methyl-3-pyrrolin-2-one as the core flanked by one mol­ecule of the dione on each side.




2

7-{3-Eth­oxy-4-[2-(2-meth­oxy­eth­oxy)eth­oxy]phen­yl}-5,6,8,9-tetra­hydro­dibenzo[c,h]acridine

In the title compound, C34H35NO4, the dihedral angle between the pyridine ring and attached benzene ring is 79.17 (8)°. The meth­oxy­eth­oxy–eth­oxy side chain is disordered over two orientations in a 0.732 (7):0.268 (7) ratio. In the crystal, very weak C—H⋯N and C—H⋯O inter­actions link the mol­ecules.




2

N,N,N-Trimethyl-1-[4-(pyridin-2-yl)phen­yl]meth­anaminium hexa­fluorido­phosphate

In the cation of the title mol­ecular salt, C15H19N2+·PF6−, the dihedral angle between the benzene and pyridine rings is 38.21 (10)°. In the crystal, weak C—H⋯F inter­actions arising from methyl and methyl­ene groups adjacent to the quaternary N atom generate (001) sheets.




2

3,4',5,5'-Tetra­meth­oxy-2'-methyl­biphen­yl-4-ol

The asymmetric unit of the title compound, C17H20O5, contains two independent mol­ecules, A and B, with similar geometries [dihedral angles between the phenyl rings = 56.19 (8) and 54.98 (7)°, respectively]. Intra­molecular O—H⋯O hydrogen bonds occur in both mol­ecules. In the crystal, the A mol­ecules form [1overline{1}0] chains linked by O—H⋯O hydrogen bonds from the hydroxyl group to one of the meth­oxy O atoms. The B mol­ecules form O—H⋯O hydrogen bonds to the hydroxyl O atoms of the A mol­ecules and thus act as fixed spacers between the chains of mol­ecule A. Some weak C—H⋯O contacts are also present.




2

Synthesis and crystal structure of [Cs([2.2.2]crypt)]2[Mo(CO)5]

Reduction of the heteroleptic metal carbonyl complex Mo(CO)3(η5-Cp)H with the metallic salt Cs5Bi4 in the presence of [2.2.2]crypt (= 4,7,13,16,21,24-hexa­oxa-1,10-di­aza­bicyclo­[8.8.8]hexa­cosa­ne) in liquid ammonia led to single crystals of bis­[(4,7,13,16,21,24-hexa­oxa-1,10-di­aza­bicyclo­[8.8.8]hexa­cosa­ne)caesium] penta­carbonyl­molybdate, [Cs(C18H36N2O6)]2[Mo(CO)5] or [Cs([2.2.2]crypt)]2[Mo(CO)5]. The twofold negatively charged anionic complex corresponds to the 18 valence electron rule. It consists of an Mo atom coordinated by five carbonyl ligands in a shape inter­mediate between trigonal–bipyramidal and square-pyramidal. The Mo—C distances range from 1.961 (3) to 2.017 (3) Å, and the C≡O distances from 1.164 (3) to 1.180 (4) Å.




2

Poly[di(μ2-2-hy­droxy­propano­ato)cadmium]

The asymmetric unit of the title inorganic–organic salt, poly[di(μ2-2-hy­droxy­propano­ato)cadmium], [Cd(C3H5O3)2]n or [Cd(Hlac)2]n (H2lac = 2-hy­droxy­propanoic acid), comprises of a cadmium cation and two 2-hy­droxy­propano­ate anions. The cadmium cation exhibits a distorted penta­gonal–bipyramidal coordination environment defined by the hy­droxy and carbonyl O atoms of the 2-hy­droxy­propano­ate anions. The coordination mode leads to the formation of layers extending parallel to (010). O—H⋯O hydrogen bonding between the hy­droxy and carbonyl groups stabilizes the structure packing.