ex Fast trashion: Exhibition of garments made from street-litter opens at Imperial | Imperial News - Imperial College London By www.imperial.ac.uk Published On :: Tue, 07 Jan 2020 08:00:00 GMT Fast trashion: Exhibition of garments made from street-litter opens at Imperial | Imperial News Imperial College London Full Article
ex What is a sinkhole and are they caused by bad weather? - expressandstar.com By www.expressandstar.com Published On :: Mon, 10 Feb 2020 08:00:00 GMT What is a sinkhole and are they caused by bad weather? expressandstar.com Full Article
ex Earthquake strikes Sussex/Surrey border | Meridian - ITV News - ITV News By www.itv.com Published On :: Sat, 04 May 2019 07:00:00 GMT Earthquake strikes Sussex/Surrey border | Meridian - ITV News ITV News Full Article
ex 'Surrey swarm' quakes 'not caused by oil extraction' - BBC News By www.bbc.com Published On :: Tue, 27 Aug 2019 07:00:00 GMT 'Surrey swarm' quakes 'not caused by oil extraction' BBC News Full Article
ex Tsunami warning: Britain could be hit by 30m wave - Professor warns of hazards to Britain - Express.co.uk By www.express.co.uk Published On :: Mon, 18 Nov 2019 08:00:00 GMT Tsunami warning: Britain could be hit by 30m wave - Professor warns of hazards to Britain Express.co.uk Full Article
ex 'Surrey swarm' earthquakes not caused by nearby oil extraction, study suggests - Science Daily By www.sciencedaily.com Published On :: Tue, 27 Aug 2019 07:00:00 GMT 'Surrey swarm' earthquakes not caused by nearby oil extraction, study suggests Science Daily Full Article
ex Coronavirus: the week explained - 10 April - The Guardian By www.theguardian.com Published On :: Fri, 10 Apr 2020 11:11:36 GMT Coronavirus: the week explained - 10 April The Guardian Full Article
ex Scientists Explain Why Earth’s Magnetic North Pole Is Drifting Away From Canada Towards Siberia - Mashable India By in.mashable.com Published On :: Fri, 08 May 2020 13:10:00 GMT Scientists Explain Why Earth’s Magnetic North Pole Is Drifting Away From Canada Towards Siberia Mashable India Full Article
ex Explained: How coronavirus lockdown reduced Earth’s seismic noise levels - The Indian Express By indianexpress.com Published On :: Sun, 12 Apr 2020 18:31:06 GMT Explained: How coronavirus lockdown reduced Earth’s seismic noise levels The Indian Express Full Article
ex Why the UK's streets have turned silent during coronavirus lockdown - Express.co.uk By www.express.co.uk Published On :: Wed, 29 Apr 2020 07:00:00 GMT Why the UK's streets have turned silent during coronavirus lockdown Express.co.uk Full Article
ex UK sees notable reduction in seismic noise caused by human activity – experts - Aberdeen Evening Express By www.eveningexpress.co.uk Published On :: Fri, 24 Apr 2020 07:00:00 GMT UK sees notable reduction in seismic noise caused by human activity – experts Aberdeen Evening Express Full Article
ex Ancient underwater landslides help predict tsunami risk - Aberdeen Evening Express By www.eveningexpress.co.uk Published On :: Thu, 23 Apr 2020 07:00:00 GMT Ancient underwater landslides help predict tsunami risk Aberdeen Evening Express Full Article
ex Fossil believed to show squid-like creature attacking fish 200 million years ago - Aberdeen Evening Express By www.eveningexpress.co.uk Published On :: Wed, 06 May 2020 15:01:00 GMT Fossil believed to show squid-like creature attacking fish 200 million years ago Aberdeen Evening Express Full Article
ex Characterization of the Pseudomonas aeruginosa T6SS PldB immunity proteins PA5086, PA5087 and PA5088 explains a novel stockpiling mechanism By scripts.iucr.org Published On :: 2020-04-28 The bacterial type VI secretion system (T6SS) secretes many toxic effectors to gain advantage in interbacterial competition and for eukaryotic host infection. The cognate immunity proteins of these effectors protect bacteria from their own effectors. PldB is a T6SS trans-kingdom effector in Pseudomonas aeruginosa that can infect both prokaryotic and eukaryotic cells. Three proteins, PA5086, PA5087 and PA5088, are employed to suppress the toxicity of PldB-family proteins. The structures of PA5087 and PA5088 have previously been reported, but the identification of further distinctions between these immunity proteins is needed. Here, the crystal structure of PA5086 is reported at 1.90 Å resolution. A structural comparison of the three PldB immunity proteins showed vast divergences in their electrostatic potential surfaces. This interesting phenomenon provides an explanation of the stockpiling mechanism of T6SS immunity proteins. Full Article text
ex Crystallographic snapshots of the EF-hand protein MCFD2 complexed with the intracellular lectin ERGIC-53 involved in glycoprotein transport By scripts.iucr.org Published On :: 2020-04-29 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. Full Article text
ex Visualization Bench for the screening of crystallization assays and the automation of in situ experiments By journals.iucr.org Published On :: Full Article text
ex Exploring the complex map of insulin polymorphism: a novel crystalline form in the presence of m-cresol By journals.iucr.org Published On :: A novel monoclinic phase of human insulin co-crystallized with m-cresol was structurally characterized by means of powder and single-crystal X-ray diffraction. Full Article text
ex Structure of ClpC1-NTD in complex with the anti-TB natural product ecumicin reveals unique binding interactions By journals.iucr.org Published On :: Comparison of the structures of ClpC1-Ecumicin and ClpC1-Rufomycin reveals unique interaction relevant to the mode of action. Full Article text
ex Structure of Thermococcus litoralis Δ1-pyrroline-2-carboxylate reductase in complex with NADH and L-proline By journals.iucr.org Published On :: 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. Full Article text
ex Crystal structure of a salt with a protonated sugar cation and a cobalt(II) complex anion: (GlcN–H, K)[Co(NCS)4]·2H2O By scripts.iucr.org Published On :: 2019-09-06 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. Full Article text
ex Bis(μ2-benzoato-κ2O,O')bis(benzoato-κO)bis(ethanol-κO)bis(μ3-hydroxido)hexakis(μ-pyrazolato-κ2N,N')hexacopper(II) ethanol disolvate By scripts.iucr.org Published On :: 2019-09-03 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. Full Article text
ex N,N,N-Trimethyl-1-[4-(pyridin-2-yl)phenyl]methanaminium hexafluoridophosphate By scripts.iucr.org Published On :: 2019-09-06 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. Full Article text
ex 4-Amino-5-{[cyclohexyl(methyl)amino]methyl}isophthalonitrile By scripts.iucr.org Published On :: 2019-10-22 The title compound, C16H20N4, was synthesized by cyanation of bromhexine. The compound crystallizes with two unique molecules in the asymmetric unit. The substituted aniline and cyclohexane rings are inclined to one another by 37.26 (6)° in one molecule and by 22.84 (7)° in the other. In the crystal packing, intra- and intermolecular N—H⋯N hydrogen bonds and an intermolecular C—H⋯N contact were observed. Full Article text
ex 2,4-Dichloro-6-[(2-hydroxy-5-methylanilino)methylidene]cyclohexa-2,4-dienone By scripts.iucr.org Published On :: 2019-10-29 The title compound, C14H11Cl2NO2, has been prepared by the condensation of 3,5-dichlorosalicylaldehyde and 2-amino-4-methylphenol. The asymmetric unit consists of two independent molecules, both of which are almost planar; the dihedral angle between the two benzene rings is 10.61 (8)° for one molecule and 2.46 (8)° for the other. There is an intramolecular N—H⋯O hydrogen bond that generates S(6) ring motifs in each molecule. In the crystal, the two independent molecules are linked by O—H⋯O and C—H⋯Cl hydrogen bonds, forming a pseudo-inversion dimer. A π–π interaction, with a centroid–centroid distance of 3.6065 (12) Å, is also observed. Full Article text
ex (4-Carboxybenzyl)triphenylphosphonium hexafluoridophosphate tetrahydrofuran monosolvate By scripts.iucr.org Published On :: 2019-11-05 The title compound, C26H22O2P+·PF6−·C4H7O, crystallizes as a cation-anion pair with a single solvent molecule in the asymmetric unit. Hydrogen bonding occurs between the carboxylic acid group on the cation and the oxygen atom of the solvent molecule. Longer hydrogen-bonding interactions are observed between fluorine atoms of the anion and H atoms on the phenyl rings of the cation. Full Article text
ex 2,2,3,3,4,4,5,5-Octafluorohexane-1,6-diol By scripts.iucr.org Published On :: 2020-04-07 In the crystal of the title compound, C6H6F8O4, O—H⋯O hydrogen bonds involving the hydroxy groups connect the molecules, forming a two-dimensional network parallel to (100). These hydrogen-bonding interactions appear to drive the O—C—C—O torsion angles into a gauche–trans–trans series of conformations along the backbone of the molecule. Full Article text
ex Tris(4,4'-di-tert-butyl-2,2'-bipyridine)(trans-4-tert-butylcyclohexanolato)deca-μ-oxido-heptaoxidoheptavanadium acetonitrile monosolvate including another unknown solvent molecule By scripts.iucr.org Published On :: 2020-04-07 The title heptanuclear alkoxido(oxido)vanadium(V) oxide cluster complex, [V7(C10H19O)O17(C18H24N2)3]·CH3CN, was obtained by the reaction of [V8O20(C18H24N2)4] with 4-tert-butylcyclohexanol (mixture of cis and trans) in a mixed CHCl3/CH3CN solvent. The complex has a V7O18N6 core with approximately Cs symmetry, which is composed of two VO4 tetrahedra, two VO6 octahedra and three VO4N2 octahedra. In the crystal, these complexes are linked together by weak intermolecular C—H⋯O hydrogen bonds between the 4,4'-di-tert-butyl-2,2'-bipyridine ligand and the V7O18N6 core, forming a one-dimensional network along the c-axis direction. Besides the complex, the asymmetric unit contains one CH3CN solvent molecule. The contribution of other disordered solvent molecules to the scattering was removed using the SQUEEZE option in PLATON [Spek (2015). Acta Cryst. C71, 9–18]. The unknown solvent molecules are not considered in the chemical formula and other crystal data. Full Article text
ex Poly[[μ4-3,4,8,10,11,13-hexahydro-1H,6H-bis([1,4]dithiocino)[6,7-b:6',7'-e]pyrazine]di-μ-iodido-dicopper(I)]: a two-dimensional copper(I) coordination polymer By scripts.iucr.org Published On :: 2020-04-07 The reaction of ligand 3,4,8,10,11,13-hexahydro-1H,6H-bis([1,4]dithiocino)[6,7-b:6',7'-e]pyrazine (L) with CuI led to the formation of a two-dimensional coordination polymer, incorporating a [Cu2I2] motif. These units are linked via the four S atoms of the ligand to form the title two-dimensional coordination polymer, poly[[μ4-3,4,8,10,11,13-hexahydro-1H,6H-bis([1,4]dithiocino)[6,7-b:6',7'-e]pyrazine]di-μ-iodido-dicopper(I)], [Cu2I2(C12H16N2S4)]n, (I). The asymmetric unit is composed of a ligand molecule, two copper(I) atoms and two I− ions. Both copper(I) atoms are fourfold S2I2 coordinate with almost regular trigonal-pyramidal environments. In the crystal, the layers, lying parallel to (102), are linked by C—H⋯I hydrogen bonds, forming a supramolecular framework. Full Article text
ex Crystal structure and Hirshfeld surface analysis of (Z)-6-[(2-hydroxy-4-methylanilino)methylidene]-4-methylcyclohexa-2,4-dien-1-one By scripts.iucr.org Published On :: 2019-05-14 The title compound, C15H15NO2, is a Schiff base that exists in the keto–enamine tautomeric form and adopts a Z configuration. The molecule is almost planar, with the two phenyl rings twisted relative to each other by 9.60 (18)°. There is an intramolecular N—H⋯O hydrogen bond present forming an S(6) ring motif. In the crystal, pairs of O—H⋯O hydrogen bonds link adjacent molecules into inversion dimers with an R22(18) ring motif. The dimers are linked by very weak π–π interactions, forming layers parallel to (overline{2}01). Hirshfeld surface analysis, two-dimensional fingerprint plots and the molecular electrostatic potential surfaces were used to analyse the intermolecular interactions, indicating that the most important contributions for the crystal packing are from H⋯H (55.2%), C⋯H/H⋯C (22.3%) and O⋯H/H⋯O (13.6%) interactions. Full Article text
ex Crystal structure and Hirshfeld surface analysis of (Z)-6-[(2-hydroxy-5-nitroanilino)methylidene]-4-methylcyclohexa-2,4-dien-1-one By scripts.iucr.org Published On :: 2019-05-17 The title compound, C14H12N2O4, is a Schiff base that exists in the keto–enamine tautomeric form and adopts a Z configuration. The molecule is almost planar, the rings making a dihedral angle of 4.99 (7)°. The molecular structure is stabilized by an intramolecular N—H⋯O hydrogen bond forming an S(6) ring motif. In the crystal, inversion-related molecules are linked by pairs of O—H⋯O hydrogen bonds, forming dimers with an R22(18) ring motif. The dimers are linked by pairs of C—H⋯O contacts with an R22(10) ring motif, forming ribbons extended along the [2overline{1}0] direction. Hirshfeld surface analysis, two-dimensional fingerprint plots and the molecular electrostatic potential surfaces were used to analyse the intermolecular interactions present in the crystal, indicating that the most important contributions for the crystal packing are from H⋯H (33.9%), O⋯H/H⋯O (29.8%) and C⋯H/H⋯C (17.3%) interactions. Full Article text
ex Crystal structure of bis(μ-{2-[(5-bromo-2-oxidobenzylidene)amino]ethyl}sulfanido-κ3N,O,S){2,2'-[(3,4-dithiahexane-1,6-diyl)bis(nitrilomethanylylidene)]bis(4-bromophenolato)-κ4O,N,N',O By scripts.iucr.org Published On :: 2019-05-24 The title binuclear CoIII complex, [Co2(C9H8BrNOS)2(C18H16Br2N2O2S2)]·C3H7NO, with a Schiff base ligand formed in situ from cysteamine (2-aminoethanethiol) and 5-bromosalicylaldehyde crystallizes in the space group P21. It was found that during the synthesis the ligand undergoes spontaneous oxidation, forming the new ligand H2L' having an S—S bond. Thus, the asymmetric unit consists of one Co2(L)2(L') molecule and one DMF solvent molecule. Each CoIII ion has a slightly distorted octahedral S2N2O2 coordination geometry. In the crystal, the components are linked into a three-dimensional network by several S⋯ Br, C⋯ Br, C—H⋯Br, short S⋯C (essentially shorter than the sum of the van der Waals radii for the atoms involved) contacts as well by weak C—H⋯O hydrogen bonds. The crystal studied was refined as an inversion twin. Full Article text
ex Zn and Ni complexes of pyridine-2,6-dicarboxylates: crystal field stabilization matters! By scripts.iucr.org Published On :: 2019-05-31 Six reaction products of ZnII and NiII with pyridine-2,6-dicarboxylic acid (H2Lig1), 4-chloropyridine-2,6-dicarboxylic acid (H2Lig2) and 4-hydroxypyridine-2,6-dicarboxylic acid (H2Lig3) are used to pinpoint the structural consequences of crystal field stabilization by an incomplete d shell. The pseudo-octahedral ZnII coordination sphere in bis(6-carboxypicolinato)zinc(II) trihydrate, [Zn(C7H4NO4)2]·3H2O or [Zn(HLig1)2]·3H2O, (1), is significantly less regular than that about NiII in the isostructural compound bis(6-carboxypicolinato)nickel(II) trihydrate, [Ni(C7H4NO4)2]·3H2O or [Ni(HLig1)2]·3H2O, (2). The ZnII complexes poly[(4-chloropyridine-2,6-dicarboxylato)zinc(II)], [Zn(C7H2ClNO4)]n or [Zn(Lig2)]n, (3), and poly[[(4-hydroxypyridine-2,6-dicarboxylato)zinc(II)] monohydrate], {[Zn(C7H3NO5)]·H2O}n or {[Zn(Lig3)]·H2O}n, (4), represent two-dimensional coordination polymers with chelating and bridging pyridine-2,6-dicarboxylate ligands in which the coordination polyhedra about the central cations cannot be associated with any regular shape; their coordination environments range between trigonal–bipyramidal and square-pyramidal geometries. In contrast, the corresponding adducts of the diprotonated ligands to NiII, namely triaqua(4-chloropyridine-2,6-dicarboxylato)nickel(II), [Ni(C7H2ClNO4)(H2O)3] or [NiLig2(OH2)3)], (5), and triaqua(4-hydroxypyridine-2,6-dicarboxylato)nickel(II) 1.7-hydrate, [Ni(C7H3NO5)(H2O)3]·1.7H2O or [NiLig3(OH2)3)]·1.7H2O, (6), feature rather regular octahedral coordination spheres about the transition-metal cations, thus precluding the formation of analogous extended structures. Full Article text
ex Synthesis, detailed geometric analysis and bond-valence method evaluation of the strength of π-arene bonding of two isotypic cationic prehnitene tin(II) complexes: [{1,2,3,4-(CH3)4C6H2}2Sn2Cl2][MCl4]2 (M = Al and Ga) By scripts.iucr.org Published On :: 2019-06-25 From solutions of prehnitene and the ternary halides (SnCl)[MCl4] (M = Al, Ga) in chlorobenzene, the new cationic SnII–π-arene complexes catena-poly[[chloridoaluminate(III)]-tri-μ-chlorido-4':1κ2Cl,1:2κ4Cl-[(η6-1,2,3,4-tetramethylbenzene)tin(II)]-di-μ-chlorido-2:3κ4Cl-[(η6-1,2,3,4-tetramethylbenzene)tin(II)]-di-μ-chlorido-3:4κ4Cl-[chloridoaluminate(III)]-μ-chlorido-4:1'κ2Cl], [Al2Sn2Cl10(C10H14)2]n, (1) and catena-poly[[chloridogallate(III)]-tri-μ-chlorido-4':1κ2Cl,1:2κ4Cl-[(η6-1,2,3,4-tetramethylbenzene)tin(II)]-di-μ-chlorido-2:3κ4Cl-[(η6-1,2,3,4-tetramethylbenzene)tin(II)]-di-μ-chlorido-3:4κ4Cl-[chloridogallate(III)]-μ-chlorido-4:1'κ2Cl], [Ga2Sn2Cl10(C10H14)2]n, (2), were isolated. In these first main-group metal–prehnitene complexes, the distorted η6 arene π-bonding to the tin atoms of the Sn2Cl22+ moieties in the centre of [{1,2,3,4-(CH3)4C6H2}2Sn2Cl2][MCl4]2 repeating units (site symmetry overline{1}) is characterized by: (i) a significant ring slippage of ca 0.4 Å indicated by the dispersion of Sn—C distances [1: 2.881 (2)–3.216 (2) Å; 2: 2.891 (3)–3.214 (3) Å]; (ii) the non-methyl-substituted arene C atoms positioned closest to the SnII central atom; (iii) a pronounced tilt of the plane of the arene ligand against the plane of the central (Sn2Cl2)2+ four-membered ring species [1: 15.59 (11)°, 2: 15.69 (9)°]; (iv) metal–arene bonding of medium strength as illustrated by application of the bond-valence method in an indirect manner, defining the π-arene bonding interaction of the SnII central atoms as s(SnII—arene) = 2 − Σs(SnII—Cl), that gives s(SnII—arene) = 0.37 and 0.38 valence units for the aluminate and the gallate, respectively, indicating that comparatively strong main-group metal–arene bonding is present and in line with the expectation that [AlCl4]− is the slightly weaker coordinating anion as compared to [GaCl4]−. Full Article text
ex Intermolecular hydrogen bonding in isostructural pincer complexes [OH-(t-BuPOCOPt-Bu)MCl] (M = Pd and Pt) By scripts.iucr.org Published On :: 2019-06-21 In the crystal structure of the isostructural title compounds, namely {2,6-bis[(di-tert-butylphosphanyl)oxy]-4-hydroxyphenyl}chloridopalladium(II), [Pd(C22H39O3P2)Cl], 1, and {2,6-bis[(di-tert-butylphosphanyl)oxy]-4-hydroxyphenyl}chloridoplatinum(II), [Pt(C22H39O3P2)Cl], 2, the metal centres are coordinated in a distorted square-planar fashion by the POCOP pincer fragment and the chloride ligand. Both complexes form strong hydrogen-bonded chain structures through an interaction of the OH group in the 4-position of the aromatic POCOP backbone with the halide ligand. Full Article text
ex Crystal structure of hexa-μ-chlorido-μ4-oxido-tetrakis{[1-(2-hydroxyethyl)-2-methyl-5-nitro-1H-imidazole-κN3]copper(II)} containing short NO2⋯NO2 contacts By scripts.iucr.org Published On :: 2019-06-25 The title tetranuclear copper complex, [Cu4Cl6O(C6H9N3O3)4] or [Cu4Cl6O(MET)4] [MET is 1-(2-hydroxyethyl)-2-methyl-5-nitro-1H-imidazole or metronidazole], contains a tetrahedral arrangement of copper(II) ions. Each copper atom is also linked to the other three copper atoms in the tetrahedron via bridging chloride ions. A fifth coordination position on each metal atom is occupied by a nitrogen atom of the monodentate MET ligand. The result is a distorted CuCl3NO trigonal–bipyramidal coordination polyhedron with the axial positions occupied by oxygen and nitrogen atoms. The extended structure displays O—H⋯O hydrogen bonding, as well as unusual short O⋯N interactions [2.775 (4) Å] between the nitro groups of adjacent clusters that are oriented perpendicular to each other. The scattering contribution of disordered water and methanol solvent molecules was removed using the SQUEEZE procedure [Spek (2015). Acta Cryst. C71, 9–16] in PLATON [Spek (2009). Acta Cryst. D65, 148–155]. Full Article text
ex Crystal structure of (E)-N-cyclohexyl-2-(2-hydroxy-3-methylbenzylidene)hydrazine-1-carbothioamide By scripts.iucr.org Published On :: 2019-06-28 The asymmetric unit of the title compound, C15H21N3OS, comprises of two crystallographically independent molecules (A and B). Each molecule consists of a cyclohexane ring and a 2-hydroxy-3-methylbenzylidene ring bridged by a hydrazinecarbothioamine unit. Both molecules exhibit an E configuration with respect to the azomethine C=N bond. There is an intramolecular O—H⋯N hydrogen bond in each molecule forming an S(6) ring motif. The cyclohexane ring in each molecule has a chair conformation. The benzene ring is inclined to the mean plane of the cyclohexane ring by 47.75 (9)° in molecule A and 66.99 (9)° in molecule B. The mean plane of the cyclohexane ring is inclined to the mean plane of the thiourea moiety [N—C(=S)—N] by 55.69 (9) and 58.50 (8)° in molecules A and B, respectively. In the crystal, the A and B molecules are linked by N—H⋯S hydrogen bonds, forming `dimers'. The A molecules are further linked by a C—H⋯π interaction, hence linking the A–B units to form ribbons propagating along the b-axis direction. The conformation of a number of related cyclohexanehydrazinecarbothioamides are compared to that of the title compound. Full Article text
ex An unexpected rhenium(IV)–rhenium(VII) salt: [Co(NH3)6]3[ReVIIO4][ReIVF6]4·6H2O By scripts.iucr.org Published On :: 2019-07-12 The title hydrated salt, tris[hexaamminecobalt(III)] tetraoxidorhenate(VII) tetrakis[hexafluoridorhenate(IV)] hexahydrate, arose unexpectedly due to possible contamination of the K2ReF6 starting material with KReO4. It consists of octahedral [Co(NH3)6]3+ cation (Co1 site symmetry 1), tetrahedral [ReVIIO4]− anions (Re site symmetry 1) and octahedral [ReIVF6]2− anions (Re site symmetries 1and overline{3}). The [ReF6]2− octahedral anions (mean Re—F = 1.834 Å), [Co(NH3)6]3+ octahedral cations (mean Co—N = 1.962 Å), and the [ReO4]− tetrahedral anion (mean Re—O = 1.719 Å) are slightly distorted. A network of N—H⋯F hydrogen bonds consolidates the structure. The crystal studied was refined as a two-component twin. Full Article text
ex The crystal structures of {LnCu5}3+ (Ln = Gd, Dy and Ho) 15-metallacrown-5 complexes and a reevaluation of the isotypic EuIII analogue By scripts.iucr.org Published On :: 2019-07-19 Three new isotypic heteropolynuclear complexes, namely pentaaquacarbonatopentakis(glycinehydroxamato)nitratopentacopper(II)lanthanide(III) x-hydrate, [LnCu5(GlyHA)5(CO3)(NO3)(H2O)5]·xH2O (GlyHA2− is glycinehydroxamate, N-hydroxyglycinamidate or aminoacetohydroxamate, C2H4N2O22−), with lanthanide(III) (LnIII) = gadolinium (Gd, 1, x = 3.5), dysprosium (Dy, 2, x = 3.28) and holmium (Ho, 3, x = 3.445), within a 15-metallacrown-5 class were obtained on reaction of lanthanide(III) nitrate, copper(II) acetate and sodium glycinehydroxamate. Complexes 1–3 contain five copper(II) ions and five bridging GlyHA2− anions, forming a [CuGlyHA]5 metallamacrocyclic core. The LnIII ions are coordinated to the metallamacrocycle through five O-donor hydroxamates. The electroneutrality of complexes 1–3 is achieved by a bidentate carbonate anion coordinated to the LnIII ion and a monodentate nitrate anion coordinated apically to one of the copper(II) ions of the metallamacrocycle. The lattice parameters of complexes 1–3 are similar to those previously reported for an EuIII–CuII 15-metallacrown-5 complex with glycinehydroxamate of proposed composition [EuCu5(GlyHA)5(OH)(NO3)2(H2O)4]·3.5H2O [Stemmler et al. (1999). Inorg. Chem. 38, 2807–2817]. High-quality X-ray data obtained for 1–3 have allowed a re-evaluation of the X-ray data solution proposed earlier for the EuCu5 complex and suggest that the formula is actually [EuCu5(GlyHA)5(CO3)(NO3)(H2O)5]·3.5H2O. Full Article text
ex A molybdenum tris(dithiolene) complex coordinates to three bound cobalt centers in three different ways By scripts.iucr.org Published On :: 2019-07-26 The synthesis and structural characterization of the molecular compound (μ3-benzene-1,2-dithiolato)hexacarbonylbis(μ3-1,1,1,4,4,4-hexafluorobut-2-ene-2,3-dithiolato)tricobaltmolybdenum, [Co3Mo(C4F6S2)2(C6H4S2)(CO)6] or Mo(tfd)2(bdt)(Co(CO)2)3 (tfd is 1,1,1,4,4,4-hexafluorobut-2-ene-2,3-dithiolate and bdt is benzene-1,2-dithiolate), are reported. The structure of the molecule contains the molybdenum tris(dithiolene) complex Mo(tfd)2(bdt) coordinated as a multidentate ligand to three cobalt dicarbonyl units. Each of the three cobalt centers is relatively close to molybdenum, with Co⋯Mo distances of 2.7224 (7), 2.8058 (7), and 2.6320 (6) Å. Additionally, each of the cobalt centers is bound via main-group donor atoms, but each one in a different way: the first cobalt atom is coordinated by two sulfur atoms from different dithiolenes (bdt and tfd). The second cobalt atom is coordinated by one sulfur from one tfd and two olefinic carbons from another tfd. The third cobalt is coordinated by one sulfur from bdt and two sulfurs from tfd. This is, to the best of our knowledge, the first structurally characterized example of a molybdenum (tris)dithiolene complex that coordinates to cobalt. The F atoms of two of the –CF3 groups were refined as disordered over two sets of sites with ratios of refined occupancies of 0.703 (7):0.297 (7) and 0.72 (2):0.28 (2). Full Article text
ex Palladium(II) complexes of a bridging amine bis(phenolate) ligand featuring κ2 and κ3 coordination modes By scripts.iucr.org Published On :: 2019-07-26 Bidentate and tridentate coordination of a 2,4-di-tert-butyl-substituted bridging amine bis(phenolate) ligand to a palladium(II) center are observed within the same crystal structure, namely dichlorido({6,6'-[(ethane-1,2-diylbis(methylazanediyl)]bis(methylene)}bis(2,4-di-tert-butylphenol))palladium(II) chlorido(2,4-di-tert-butyl-6-{[(2-{[(3,5-di-tert-butyl-2-hydroxyphenyl)methyl](methyl)amino}ethyl)(methyl)amino]methyl}phenolato)palladium(II) methanol 1.685-solvate 0.315-hydrate, [PdCl2(C34H56N2O2)][PdCl(C34H55N2O2)]·1.685CH3OH·0.315H2O. Both complexes exhibit a square-planar geometry, with unbound phenol moieties participating in intermolecular hydrogen bonding with co-crystallized water and methanol. The presence of both κ2 and κ3 coordination modes arising from the same solution suggest a dynamic process in which phenol donors may coordinate or dissociate from the metal center, and offers insight into catalyst speciation throughout Pd-mediated processes. The unit cell contains dichlorido({6,6'-[(ethane-1,2-diylbis(methylazanediyl)]bis(methylene)}bis(2,4-di-tert-butylphenol))palladium(II), {(L2)PdCl2}, and chlorido(2,4-di-tert-butyl-6-{[(2-{[(3,5-di-tert-butyl-2-hydroxyphenyl)methyl](methyl)amino}ethyl)(methyl)amino]methyl}phenolato)palladium(II), {(L2X)PdCl}, molecules as well as fractional water and methanol solvent molecules. Full Article text
ex Crystal structures of four dimeric manganese(II) bromide coordination complexes with various derivatives of pyridine N-oxide By scripts.iucr.org Published On :: 2019-07-30 Four manganese(II) bromide coordination complexes have been prepared with four pyridine N-oxides, viz. pyridine N-oxide (PNO), 2-methylpyridine N-oxide (2MePNO), 3-methylpyridine N-oxide (3MePNO), and 4-methylpyridine N-oxide (4MePNO). The compounds are bis(μ-pyridine N-oxide)bis[aquadibromido(pyridine N-oxide)manganese(II)], [Mn2Br4(C5H5NO)4(H2O)2] (I), bis(μ-2-methylpyridine N-oxide)bis[diaquadibromidomanganese(II)]–2-methylpyridine N-oxide (1/2), [Mn2Br4(C6H7NO)2(H2O)4]·2C6H7NO (II), bis(μ-3-methylpyridine N-oxide)bis[aquadibromido(3-methylpyridine N-oxide)manganese(II)], [Mn2Br4(C6H7NO)4(H2O)2] (III), and bis(μ-4-methylpyridine N-oxide)bis[dibromidomethanol(4-methylpyridine N-oxide)manganese(II)], [Mn2Br4(C6H7NO)4(CH3OH)2] (IV). All the compounds have one unique MnII atom and form a dimeric complex that contains two MnII atoms related by a crystallographic inversion center. Pseudo-octahedral six-coordinate manganese(II) centers are found in all four compounds. All four compounds form dimers of Mn atoms bridged by the oxygen atom of the PNO ligand. Compounds I, II and III exhibit a bound water of solvation, whereas compound IV contains a bound methanol molecule of solvation. Compounds I, III and IV exhibit the same arrangement of molecules around each manganese atom, ligated by two bromide ions, oxygen atoms of two PNO ligands and one solvent molecule, whereas in compound II each manganese atom is ligated by two bromide ions, one O atom of a PNO ligand and two water molecules with a second PNO molecule interacting with the complex via hydrogen bonding through the bound water molecules. All of the compounds form extended hydrogen-bonding networks, and compounds I, II, and IV exhibit offset π-stacking between PNO ligands of neighboring dimers. Full Article text
ex Crystal structure of a binuclear mixed-valence ytterbium complex containing a 2-anthracene-substituted phenoxide ligand By scripts.iucr.org Published On :: 2019-08-23 Reaction of 2-(anthracen-9-yl)phenol (HOPhAn, 1) with divalent Yb[N(SiMe3)2]2·2THF in THF–toluene mixtures affords the mixed-valence YbII–YbIII dimer {[2-(anthracen-9-yl)phenolato-κO]bis(tetrahydrofuran)ytterbium(III)}-tris[μ-2-(anthracen-9-yl)phenolato]-κ4O:O;κO:1,2-η,κO-{[2-(anthracen-9-yl)phenolato-κO]ytterbium(II)} toluene trisolvate, [Yb2(C20H13O)5(C4H8O)2]·3C7H7 or [YbIII(THF)2(OPhAn)](μ-OPhAn)3[YbII(OPhAn)]·3C7H7 (2), as the major product. It crystallized as a toluene trisolvate. The Yb—O bond lengths in the crystal structure of this dimer clearly identify the YbII and YbIII centres. Interestingly, the formally four-coordinate YbII centre shows a close contact with one anthracene C—C bond of a bridging OPhAn ligand, bringing the formal coordination number to five. Full Article text
ex The synthesis and crystal structure of bis[3,3-diethyl-1-(phenylimino-κN)thiourea-κS]silver hexafluoridophosphate By scripts.iucr.org Published On :: 2019-08-30 The structure of the title complex, [Ag(C11H15N3S)2]PF6, has monoclinic (P21/c) symmetry, and the silver atom has a distorted square-planar geometry. The coordination complex crystallized from mixing silver hexafluoridophosphate with a concentrated tetrahydrofuran solution of N,N-diethylphenylazothioformamide [ATF; systematic name: 3,3-diethyl-1-(phenylimino)thiourea] under ambient conditions. The resultant coordination complex exhibits a 2:1 ligand-to-metal ratio, with the silver(I) atom having a fourfold AgN2S2 coordination sphere, with a single PF6 counter-ion. In the crystal, however, one sulfur atom from an ATF ligand of a neighboring complex coordinates to the silver atom, with a bond distance of 2.9884 (14) Å. This creates a polymeric zigzag chain propagating along the c-axis direction. The chains are linked by C—H⋯F hydrogen bonds, forming slabs parallel to the ac plane. Full Article text
ex Crystal structure and molecular Hirshfeld surface analysis of acenaphthene derivatives obeying the chlorine–methyl exchange rule By scripts.iucr.org Published On :: 2019-09-12 Instances of crystal structures that remain isomorphous in spite of some minor changes in their respective molecules, such as change in a substituent atom/group, can provide insights into the factors that govern crystal packing. In this context, an accurate description of the crystal structures of an isomorphous pair that differ from each other only by a chlorine–methyl substituent, viz. 5''-(2-chlorobenzylidene)-4'-(2-chlorophenyl)-1'-methyldispiro[acenaphthene-1,2'-pyrrolidine-3',3''-piperidine]-2,4''-dione, C34H28Cl2N2O2, (I), and its analogue 1'-methyl-5''-(2-methylbenzylidene)-4'-(2-methylphenyl)dispiro[acenaphthene-1,2'-pyrrolidine-3',3''-piperidine]-2,4''-dione, C36H34N2O2, (II), is presented. While there are two C—H⋯O weak intermolecular interactions present in both (I) and (II), the change of substituent from chlorine to methyl has given rise to an additional weak C—H⋯O intermolecular interaction that is relatively stronger than the other two. However, the presence of the stronger C—H⋯O interaction in (II) has not disrupted the validity of the chloro-methyl exchange rule. Details of the crystal structures and Hirshfeld analyses of the two compounds are presented. Full Article text
ex The crystal structure of ((cyclohexylamino){(Z)-2-[(E)-5-methoxy-3-nitro-2-oxidobenzylidene-κO]hydrazin-1-ylidene-κN2}methanethiolato-κS)(dimethyl sulfoxide-κS)platinum(II): a supramolecular two-dimens By scripts.iucr.org Published On :: 2019-09-12 The PtII atom in the title complex, [Pt(C15H18N4O4S)(C2H6OS)], exists within a square-planar NS2O donor set provided by the N, S, O atoms of the di-anionic tridentate thiosemicarbazo ligand and a dimethyl sulfoxide S atom. The two chelate rings are coplanar, subtending a dihedral angle of 1.51 (7)°. The maximum deviation from an ideal square-planar geometry is seen in the five-membered chelate ring with an S—Pt—S bite angle of 96.45 (2)°. In the crystal, molecules are linked via N—H⋯O, C—H⋯O, C—H⋯N and C—H⋯π interactions into two-dimensional networks lying parallel to the ab plane. The conformations of related cyclohexylhydrazine-1-carbothioamide ligands are compared to that of the title compound. Full Article text
ex Crystal structure and Hirshfeld surface analysis of bis[hydrazinium(1+)] hexafluoridosilicate: (N2H5)2SiF6 By scripts.iucr.org Published On :: 2019-09-20 In the title inorganic molecular salt, (N2H5)2SiF6, the silicon atom at the centre of the slightly distorted SiF6 octahedron [range of Si—F distances = 1.6777 (4)–1.7101 (4) Å] lies on a crystallographic inversion centre. In the crystal, the ions are connected by N—H⋯N and N—H⋯F hydrogen bonds; the former link the cations into [010] chains and the latter (some of which are bifurcated or trifurcated) link the ions into a three-dimensional network. The two-dimensional fingerprint plots show that F⋯H/H⋯F interactions dominate the Hirshfeld surface (75.5%) followed by H⋯H (13.6%) and N⋯H/H⋯N (8.4%) whereas F⋯F (1.9%) and F⋯N/N⋯F (0.6%) have negligible percentages. The title compound is isostructural with its germanium-containing analogue. Full Article text
ex The crystal structures and Hirshfeld surface analysis of 6-(naphthalen-1-yl)-6a-nitro-6,6a,6b,7,9,11a-hexahydrospiro[chromeno[3',4':3,4]pyrrolo[1,2-c]thiazole-11,11'-indeno[1,2-b]quinoxaline] and 6'-(naphthalen-1-yl)-6a By scripts.iucr.org Published On :: 2019-09-27 The title compounds, 6-(naphthalen-1-yl)-6a-nitro-6,6a,6 b,7,9,11a-hexahydrospiro[chromeno[3',4':3,4]pyrrolo[1,2-c]thiazole-11,11'-indeno[1,2-b]quinoxaline], C37H26N4O3S, (I), and 6'-(naphthalen-1-yl)-6a'-nitro-6',6a',6b',7',8',9',10',12a'-octahydro-2H-spiro[acenaphthylene-1,12'-chromeno[3,4-a]indolizin]-2-one, C36H28N2O4, (II), are new spiro derivatives, in which both the pyrrolidine rings adopt twisted conformations. In (I), the five-membered thiazole ring adopts an envelope conformation, while the eight-membered pyrrolidine-thiazole ring adopts a boat conformation. An intramolecular C—H⋯N hydrogen bond occurs, involving a C atom of the pyran ring and an N atom of the pyrazine ring. In (II), the six-membered piperidine ring adopts a chair conformation. An intramolecular C—H⋯O hydrogen bond occurs, involving a C atom of the pyrrolidine ring and the keto O atom. For both compounds, the crystal structure is stabilized by intermolecular C—H⋯O hydrogen bonds. In (I), the C—H⋯O hydrogen bonds link adjacent molecules, forming R22(16) loops propagating along the b-axis direction, while in (II) they form zigzag chains along the b-axis direction. In both compounds, C—H⋯π interactions help to consolidate the structure, but no significant π–π interactions with centroid–centroid distances of less than 4 Å are observed. Full Article text
ex Crystal structures of three hexakis(fluoroaryloxy)cyclotriphosphazenes By scripts.iucr.org Published On :: 2019-09-27 The syntheses and crystal structures of three cyclotriphosphazenes, all with fluorinated aryloxy side groups that generate different steric characteristics, viz. hexakis(pentafluorophenoxy)cyclotriphosphazene, N3P3(OC6F5)6, 1, hexakis[4-(trifluoromethyl)phenoxy]cyclotriphosphazene, N3P3[OC6H4(CF3)]6, 2 and hexakis[3,5-bis(trifluoromethyl)phenoxy]cyclotriphosphazene, N3P3[OC6H3(CF3)2]6 3, are reported. Specifically, each phosphorus atom bears either two pentafluorophenoxy, 4-trifluoromethylphenoxy, or 3,5-trifluoromethylphenoxy groups. The central six-membered phosphazene rings display envelope pucker conformations in each case, albeit to varying degrees. The maximum displacement of the `flap atom' from the plane through the other ring atoms [0.308 (5) Å] is seen in 1, in a molecule that is devoid of hydrogen atoms and which exhibits a `wind-swept' look with all the aromatic rings displaced in the same direction. In 3 an intramolecular C—H(aromatic)⋯F interaction is observed. All the –CF3 groups in 2 and 3 exhibit positional disorder over two rotated orientations in close to statistical ratios. The extended structures of 2 and 3 are consolidated by C—H⋯F interactions of two kinds: (a) linear chains, and (b) cyclic between molecules related by inversion centers. In both 1 and 3, one of the six substituted phenyl rings has a parallel-displaced aromatic π–π stacking interaction with its respective symmetry mate with slippage values of 2.2 Å in 1 and 1.0 Å in 3. None of the structures reported here have solvent voids that could lead to clathrate formation. Full Article text
ex Crystal structure and DFT study of a zinc xanthate complex By scripts.iucr.org Published On :: 2019-10-03 In the title compound, bis(2-methoxyethyl xanthato-κS)(N,N,N',N'-tetramethylethylenediamine-κ2N,N')zinc(II) acetone hemisolvate, [Zn(C4H7O2S2)2(C6H16N2)]·0.5C3H6O, the ZnII ion is coordinated by two N atoms of the N,N,N',N'-tetramethylethylenediamine ligand and two S atoms from two 2-methoxyethyl xanthate ligands. The amine ligand is disordered over two orientations and was modelled with refined occupancies of 0.538 (6) and 0.462 (6). The molecular structure features two C—H⋯O and two C—H⋯S intramolecular interactions. In the crystal, molecules are linked by weak C—H⋯O and C—H⋯S hydrogen bonds, forming a three-dimensional supramolecular architecture. The molecular structure was optimized using density functional theory (DFT) at the B3LYP/6–311 G(d,p) level. The smallest HOMO–LUMO energy gap (3.19 eV) indicates the suitability of this crystal for optoelectronic applications. The molecular electrostatic potential (MEP) further identifies the positive, negative and neutral electrostatic potential regions of the molecules. Half a molecule of disordered acetone was removed with the solvent-mask procedure in OLEX2 [Dolomanov et al. (2009). J. Appl. Cryst. 42, 339–341] and this contribition is included in the formula. Full Article text
ex Crystal structures of two charge–transfer complexes of benzo[1,2-c:3,4-c':5,6-c'']trithiophene (D3h-BTT) By scripts.iucr.org Published On :: 2019-09-30 Benzo[1,2-c:3,4-c':5,6-c'']trithiophene (D3h-BTT) is an easily prepared electron donor that readily forms charge–transfer complexes with organic acceptors. We report here two crystal structures of its charge–transfer complexes with 7,7,8,8-tetracyanoquinodimethane (TCNQ) and buckminsterfullerene (C60). The D3h-BTT·TCNQ complex, C12H6S3·C12H4N4, crystallizes with mixed layers of donors and acceptors, with an estimated degree of charge transfer at 0.09 e. In the D3h-BTT·C60·toluene complex, C12H6S3·C60·C7H8, the central ring of BTT is `squeezed' by the C60 molecules from both faces. However, the degree of charge transfer is low. The C60 unit is disordered over two sites in a 0.766 (3):0.234 (3) ratio and was refined as a two-component inversion twin. Full Article text