forthcoming articles

The following articles are a selection of those recently accepted for publication in IUCr journals.

IUCrJ
Accepted 5 September 2016

Lytic polysaccharide monooxygenases: a crystallographer's view on a new class of biomass-degrading enzymes

Lytic polysaccharide monooxygenases (LPMOs) are a new class of metalloenzymes discovered in the last decade. LPMOs are now thought to be key enzymes in the biological and biotechnological degradation of biomass and are here reviewed from a structural biology viewpoint.

Accepted 1 September 2016

Angular correlations of photons from solution diffraction at a free-electron laser encode molecular structure

An atomic twinning structure is observed by averaging intensity correlations from many snapshots of gold nanoparticles in solution.
Journal logoActa Crystallographica Section A
Acta Crystallographica
Section A
FOUNDATIONS AND ADVANCES

Accepted 21 September 2016

Thermal evolution of Mg—Al and Ni—Al layered double hydroxides: the structure of dehydrated phase

A loss of water molecules leads to the topotactic transformation of the initial structure of Mg—Al and Ni—Al layered double hydroxides having the hydro­talcite-like structure and consisting of 3R1 and 2H1 layered fragments having trigonal prismatic interlayers. The structure of dehydrated phase comprises turbostratically disordered 3R2 and 1H layered fragments having octahedral interlayers that can be related to the change of orientation of interlayer anions and the appearance of tetrahedrally coordinated cations in the interlayers.

Accepted 31 August 2016

Two-periodic self-dual tilings

All uninodal, binodal and trinodal 2-periodic self-dual tilings are enumerated and described.

Accepted 27 August 2016

Revisit La0.5Sr1.5MnO4 Lattice Distortion and Charge Ordering with Multi-Beam Resonant Diffraction

Sinusoidal wave type distortions of La0.5Sr1.5MnO4 in low temperature orthorhombic phase were observed using multi-beam resonant X-ray diffraction and dynamical theory.

Accepted 24 August 2016

Peter J. W. Debye - A whole life devoted to science


Accepted 22 August 2016

Observing structural reorientations at solvent-nanoparticle interfaces by X-ray diffraction - putting water in the spotlight

Nanoparticles and solvents interact and interdependently change their structural arrangement, as probed by X-ray pair distribution function.

Accepted 22 August 2016

Sphere packings as a tool for the description of martensitic phase transformations

Martensitic phase transformations are described by means of group-subgroup relations and sphere-packing considerations.

Accepted 16 August 2016

An alternative to the goodness of fit

A robust alternative to the goodness of fit is derived, aGoFs, and a systematic error in the experimental s.u.'s is found with the help of the aGoFs, which effectively veils the presence of other systematic errors.

Accepted 5 August 2016

Towards atomistic understanding of polymorphism in the solvothermal synthesis of ZrO2 nanoparticles

The chemical path towards different polymorphs in the solvothermal synthesis of zirconia nanoparticles is decided by a complex interplay among reactants and applied conditions: at low temperature the structural similarity between the amorphous intermediate phase and monoclinic ZrO2 results in almost phase-pure ∼5 nm monoclinic-ZrO2. Atomic scale pair distribution function analysis over the entire course of the reaction provides an understanding, and thereby control, of nanoparticle polymorphism. [Author: temperatures converted to K as per journal policy. Fig. S9 is in celsius - please supply an updated file. Also two references are cited only in the supporting information. Please include a citation in the main text]

Accepted 29 July 2016

Direct observation of incommensurate structure in Mo3Si

Mo3Si with a small off-stoichiometry in composition has an incommensurate crystal structure with a non-cubic unit cell. Atom-probe tomography and atomic resolution Z-contrast imaging suggest that site substitution causes the development of split atomic positions, disorder and vacancies.

Accepted 25 July 2016

Residue-based scattering factors

Amino-acid residues are chosen to form globs and empirical formulas for residue-based scattering factors have been developed.

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Journal logoActa Crystallographica Section B
Acta Crystallographica
Section B
STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS

Accepted 5 September 2016

Solvates of selected fenamic acids with substituted pyridines: structure, thermal stability and desolvation

Mefenamic acid and tolfenamic acid form solvates with selected substituted pyridines. The crystal structures, thermal stability, desolvation studies and other modes of preparation were also determined.

Accepted 2 September 2016

Vacancy pairing and superstructure in the high-pressure silicate K1.5Mg2Si2O7H0.5: a new potential host for potassium in the deep Earth

The superstructure of a novel high-pressure hydrous silicate K1.5Mg2Si2O7H0.5 relevant to the water budget of the Earth's mantle has been determined and its crystal chemistry discussed in relation to its stabilization at mantle conditions.

Accepted 22 August 2016

Neutron and high-pressure X-ray diffraction study of hydrogen-bonded ferroelectric rubidium hydrogen sulfate

The hydrogen-bonded ferroelectric material rubidium hydrogen sulfate has been investigated through a combination of high-pressure X-ray diffraction and neutron Laue diffraction. This study confirms the order–disorder origin of the ferroelectric transition as well as fully characterizing the high-pressure phase transition.

Accepted 18 July 2016

Accurate unrestrained DDM refinement of crystal structures from highly distorted and low-resolution powder diffraction data

Crystal structures of the benzene:ethane co-crystal and 2-aminopyridinium fumarate–fumaric acid are refined without geometric restraints using the derivative difference method from strongly distorted synchrotron and low-resolution laboratory X-ray powder diffraction data. The results are compared with density functional theory calculations and former restrained Rietveld refinements for the same datasets.

Accepted 15 July 2016

Variable-temperature X-ray diffraction study of structural parameters of NH---S hydrogen bonds in tri­ethylammonium and pyridinium silane­thiolates

Hydrogen bonds in triethylammonium and pyridinium silanethiolate salts have been characterized by X-ray, FT–IR and NMR spectroscopies. DFT calculations reveal strongly asymmetric double-well minima at the potential energy curves of the studied compounds.

Accepted 13 July 2016

Mutual transformation between crystalline phases in silicon after treatment in a planetary mill: HRTEM studies

Silicon particles after treatment in a planetary mill have been examined in transmission electron microscopy. It is shown that along with the initial phase of silicon, Si-I, the sample also contains some high-pressure phases: Si-III (Kasper phase) and Si-IV (lonsdaleite). We studied the orientation relationship between the particles of different phases.

Accepted 8 July 2016

Crystal structure of the orthorhombic pseudopolymorph for tacrine hydrochloride

The orthorhombic pseudopolymorph of the acetylcholinesterase inhibitor tacrine hydrochloride was obtained after recrystallization from a water:ethanol mixture.

Accepted 6 July 2016

Crystal chemistry of tri­alkylsilyl-capped (3Z)-4-(methylthio)-3-penten-1-yne: polymorphism, twinning and ambiguity of order–disorder descriptions

Silyl-capped ene-yne compounds crystallize in layers and feature polymorphism and twinning.

Accepted 29 June 2016

Topological characterization of electron density, electrostatic potential and intermolecular interactions of 2-nitro­imidazole: an experimental and theoretical study

In this paper we present a detailed investigation of experimental and theoretical charge density analysis and electrostatic properties of the 2-nitroimidazole molecule. The topological properties of electron density reveal the charge density distribution of the molecule and non-bonding regions.

Accepted 29 June 2016

Structures and physicochemical properties of vortioxetine salts

Eight salts of vortioxetine were synthesized and structurally elucidated by single-crystal structure analysis. Physical and chemical properties were evaluated by a variety of analytical techniques. Vortioxetine aspartate dihydrate shows a higher solubility than the corresponding anhydrate.

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Journal logoActa Crystallographica Section C
Acta Crystallographica
Section C
STRUCTURAL CHEMISTRY

Accepted 22 September 2016

Acetic anhydride at 100 K: the first crystal structure determination

Acetic anhydride is a widely used acetyl­ation reagent in organic synthesis. The crystal and mol­ecular structure, as determined by single-crystal X-ray analysis at 100 K, is reported for the first time. The mol­ecule adopts an exact C2-symmetric conformation about a crystallographic twofold axis.

Accepted 21 September 2016

Cocrystals of 1,4-diethynyl­benzene with 1,3-di­acetyl­benzene and benzene-1,4-dicarbaldehyde exhibiting strong nonconventional alkyne–carbonyl C—H⋯O hydrogen bonds between the components

The 1:1 cocrystal of 1,4-diethynyl­benzene with 1,3-di­acetyl­benzene and the 1:1 cocrystal of 1,4-diethynyl­benzene with benzene-1,4-dicarbaldehyde feature a strong nonconventional ethyn­yl–carbonyl sp-C—H⋯O hydrogen bond between the components.

Accepted 27 July 2016

A pseudo­tetra­hedral nickel(II) complex with a tridentate oxazoline-based scorpionate ligand: chlorido­[tris­(4,4-di­methyl­oxazolin-2-yl)phenyl­borato]nickel(II)

Three N atoms from the facially capping tridentate chelating tris­(4,4-di­methyl­oxazolin-2-yl)phenyl­borate ligand and a chloride ligand coordinate an NiII ion in a highly distorted tetra­hedral geometry. The Ni—Cl bond length [2.1851 (5) Å] is comparable to those found in a previously reported tris­(3,5-di­methyl­pyrazol-1-yl)hydro­borate derivative [2.1955 (18) and 2.150 (2) Å]. The mol­ecular structure deviates from C3v symmetry due to the structural flexibility of the tris­(4,4-di­methyl­oxazolin-2-yl)phenyl­borate ligand.

Accepted 27 July 2016

Silver(I) and rhenium(I) metal complexes of a 2,2′-bi­pyridine-functionalized third-generation tris­(pyrazol­yl)methane ligand

The heteroditopic Bipy–CH2–O–CH2–C(pz)3 ligand (Bipy-L; Bipy is 2,2′-bi­pyridine and pz is pyrazol­yl) reacts with AgI and ReI metallic centers to yield the {[Ag(μ-Bipy-L)]BF4·0.5Et2O}n coordination polymer and the [ReBr(Bipy-L)(CO)3] monometallic compound.

Accepted 24 July 2016

FcTp(R) (R = iPr or tBu): third-generation ferrocenyl scorpionates

Thallium(I) and cobalt(II) halide complexes of the ferrocenyltris(3-R-pyrazol­yl)borate ligand (FcTpR, with R = iPr or tBu) have been synthesized and their structural characteristics determined to expand the range of redox-active third-generation scorpionates.

Accepted 22 July 2016

Structure and physicochemical characterization of a naproxen–picolinamide cocrystal

The crystal structure is reported of a new 1:1 cocrystal of naproxen with picolinamide, and the pharmaceutically relevant properties are investigated. An NMR crystallography approach is used to distinguish between two crystallographically unique COOH–CONH hydrogen-bonded dimers and to confirm the location of the H atoms in the two dimers.

Accepted 15 July 2016

Side-on coordination mode of a pyrazolyl group in the structure of a divalent [Sm{B(3-Mepz)4}2] complex (3-Mepz is 3-methyl­pyrazol-1-yl)

Bis[tetra­kis­(3-methyl-1H-pyrazol-1-yl)borato]samarium(II) was synthesized by the reaction of SmI2 with potassium tetra­kis­(3-methyl­pyrazol­yl)borate in tetrahydrofuran. The X-ray structure analysis revealed an unusual side-on coordination mode of a 3-methyl­pyrazolyl group through an N=N group in the B(3-Mepz)4 ligand. The distortion is defined by the B—N—N—Sm torsion angle [85.5 (4)°].

Accepted 29 June 2016

Mono- and binuclear tris­(3-tert-butyl-2-sulfanyl­idene-1H-imidazol-1-yl)hydro­borate bis­muth(III) dichloride complexes: a soft scorpionate ligand can coordinate to p-block elements

The structure of a new mononuclear bis­muth(III) complex with the soft scorpionate ­(3-tert-butyl-2-sulfanyl­idene-1H-imidazol-1-yl)hydro­borate ligand is compared with that of the binuclear derivative.

Accepted 2 June 2016

Mol­ecular structures of tris­(1-tert-butyl-2-mercapto­imidazol­yl)hydro­borate complexes of titanium, zirconium and hafnium

The structural characterization of the tris(1-tert-butyl-2-mercaptoimidazol­yl)hydro­borate, [TmBut], complexes Cp[κ3S2,H-TmBut]MCl2 (M = Zr and Ti) by X-ray diffraction demonstrates that the [TmBut] ligand coordinates in a κ3S2,H mode, while the benzyl compounds [TmBut]M(CH2Ph)3 (M = Zr and Hf) exhibit κ3S3 coordination.
Journal logoActa Crystallographica Section D
Acta Crystallographica
Section D
STRUCTURAL BIOLOGY

Accepted 17 September 2016

A public database of macromolecular diffraction experiments

The Integrated Resource for Reproducibility in Macromolecular Crystallography (IRRMC) is a large, scalable and searchable web-accessible archive of protein crystallography diffraction experiments organized according to metadata.

Accepted 13 September 2016

Automated refinement of macromolecular structures at low resolution using prior information

An automated pipeline for low-resolution structure refinement (LORESTR) has been developed to assist in the hassle-free refinement of difficult cases. The pipeline automates the selection of high-resolution homologues for external restraint generation and optimizes the parameters for ProSMART and REFMAC5, improving R factors and geometry statistics in 94% of the test cases.

Accepted 9 September 2016

Using more than 801,296 small molecule crystal structures to aid in protein structure refinement and analysis

A guide to how the Cambridge Structural Database can be used to aid macromolecular crystallography.

Accepted 9 September 2016

Conservation in the mechanism of glucuronoxylan hydrolysis revealed by the structure of glucuronoxylan xylano­hydrolase (CtXyn30A) from Clostridium thermocellum

The thermostable glucuronoxylan endo-β-1,4-xylanase from C. thermocellum cleaves the xylan chain specifically at sites containing 4-O-methylglucuronic acid substitutions. The structure of the ligand-bound enzyme mutant E225A solved at 1.17 Å resolution shows binding of the xylotetraose-cleavage oligosaccharides at subsites −3 to +2.

Accepted 23 August 2016

Glycoblocks: a schematic three-dimensional representation for glycans and their interactions

With structural glycoscience finally catching fire, the need for a clear way of depicting glycans and their interactions in three dimensions is more pressing than ever. Here the Glycoblocks representationis introduced, which combines a simplified bonding network depiction with the familiar two-dimensional glycan notation, brought into three-dimensions.

Accepted 13 June 2016

WONKA and OOMMPPAA: analysis of protein–ligand interaction data to direct structure-based drug design

The background to and development of WONKA and OOMMPPAA, tools for structure-based drug design, is described.
Journal logoActa Crystallographica Section E
Acta Crystallographica
Section E
CRYSTALLOGRAPHIC COMMUNICATIONS

Accepted 21 September 2016

Crystal structures of diformatotri­methyl­tin di­aquadi-μ-hydroxido-tris­(tri­methyl­stannate) and di-μ-hydroxido-tris­(tri­methyl­tin) chloride monohydrate

The title compounds are partially condensed products of hydrolysed tri­methyl­tin chloride. In the two structures, short cationic tris­tannatoxanes (C9H29O2Sn3) are bridged by a diformatotri­methyl­tin anion or a chloride anion.

Accepted 21 September 2016

Di­methyl­ammonium 2,4,5-tri­carb­oxy­benzoate: an example of the deca­rbonylation of N,N-di­methyl­formamide in the presence of a metal and a benzene­polycarb­oxy­lic acid. Is zirconium(IV) the Tsotsi?

The paper reports the mol­ecular and crystal structure of the salt (CH3)2NH2+·C10H5O8, with the cation formed by the deca­rbonylation of DMF solvent.

Accepted 21 September 2016

[N-Benzyl-N-(2-phenyl­eth­yl)di­thio­carbamato-κ2S,S′]tri­phenyl­tin(IV) and [bis­(2-meth­oxy­eth­yl)di­thio­carbamato-κ2S,S′]tri­phenyl­tin(IV): crystal structures and Hirshfeld surface analysis

Heavily distorted trigonal–pyramidal coordination geometries, each based on a C3S2 donor set and with the loosely bound S atom approximately trans to one of the ipso-C atoms, are found in the title compounds (C6H5)3Sn[S2CN(Ben)CH2CH2Ph] and (C6H5)3Sn[S2CN(CH2CH2OMe)2].

Accepted 19 September 2016

Crystal structure of bis­(azido-κN)bis­(quinolin-8-amine-κ2N,N′)iron(II)

Exploring the role of azido anions led to the structure of this heteroleptic Fe complex with two azide ions and two quinolin-8-amine ligands.

Accepted 1 September 2016

Crystal structures of (5RS)-(Z)-4-[5-(furan-2-yl)-3-phenyl-4,5-di­hydro-1H-pyrazol-1-yl]-4-oxobut-2-enoic acid and (5RS)-(Z)-4-[5-(furan-2-yl)-3-(thio­phen-2-yl)-4,5-di­hydro-1H-pyrazol-1-yl]-4-oxobut-2-enoic acid

Stereochemical peculiarities of (5RS)-(Z)-4-[5-(furan-2-yl)-3-phenyl-4,5-di­hydro-1H-pyrazol-1-yl]-4-oxobut-2-enoic acid and (5RS)-(Z)-4-[5-(furan-2-yl)-3-(thio­phen-2-yl)-4,5-di­hydro-1H-pyrazol-1-yl]-4-oxobut-2-enoic acid, studied by X-ray structural analysis, render impossible their transformation into 3b,6-ep­oxy­pyrazolo­[5,1-a]iso­indoles by a thermal intra­molecular Diels–Alder reaction of furan (the IMDAF reaction).
Journal logoActa Crystallographica Section F
Acta Crystallographica
Section F
STRUCTURAL BIOLOGY COMMUNICATIONS

Accepted 20 August 2016

Expression and crystallographic studies of the Arabidopsis thaliana GDP-D-mannose pyro­phosphorylase VTC1

The GDP-D-mannose pyrophosphorylase VTC1 from A. thaliana was crystallized and co-crystallized with its substrate. X-ray diffraction data were collected for crystallographic analysis.
Journal logoJournal of Applied Crystallography Journal of Applied
Crystallography

Accepted 21 September 2016

Crystallography of the Mg2Y precipitates in a damping Mg-Cu-Mn-Zn-Y alloy

The novel orientation relationship, the crystallographic morphology and the defect structure across interfaces of the Mg2Y precipitates in an as-cast Mg-Cu-Mn-Zn-Y damping alloy has been reported in the present work.These results will shed light on the formation of the moveable dislocations and its association with the damping properties, which is critical in microstructure design of damping Mg alloys.

Accepted 21 September 2016

Determination of closed porosity in rocks by small-angle neutron scattering

A new methodology has been developed to determine the fraction of open and closed porosity without reaching to zero average contrast (ZAC) condition using (ultra) small-angle neutron scattering.

Accepted 14 September 2016

Effect of composition and aging on the porous structure of metakaolin-based geopolymers

By using intrusive and scattering techniques, the characteristics of the porous network and its evolution over time of geopolymers are determined according to the chemical formulation parameters

Accepted 13 September 2016

Growth, structural and physical properties of diiso­propyl­ammonium bromide molecular single crystal

Diiso­propyl­ammonium bromide single crystals were grown by slow evaporation technique with twinned, Hirshfeld surface, ferroelectric and photoluminescence analysis.

Accepted 8 September 2016

Versatile electrochemical cell for Li-/Na-ion batteries and high-throughput setup for combined operando X-ray diffraction and absorption spectroscopy

An operando set-up, that enables deep insights into working mechanisms of electrode materials under working conditions using quasi-simultaneous XRD, XANES and EXAFS analysis, is described.

Accepted 8 September 2016

The use of Haptic Interfaces and Web-Based Information in Crystallography: An Application to a 'Screen to Beam' Interface

haptic interface and related database is used to assess crystallization screening, share results, and enable efficient in-situ diffraction characterization of resulting crystals.

Accepted 7 September 2016

Highly dense stacking faults in supersaturated nitrided layer on austenitic stainless steel

Dense stacking faults in supersaturated nitrided layer produced on austenitic stainless steel were systematically investigated by TEM, and then a novel microstructure model of clustered stacking faults embedded in f.c.c. structure was built.

Accepted 6 September 2016

Direct Monitoring of Calcium-Triggered Phase Transitions in Cubosomes Using SAXS Combined with Microfluidics

Combination of microfluidics with X-ray techniques for performing dynamic structural studies on nanoparticulate formulations.

Accepted 5 September 2016

Stress influence on the properties of Ge nanocrystals in SiO2 matrix

We explored the stress which develops during the growth of Ge QDs in silica matrix, and how it affects the materials properties.

Accepted 5 September 2016

On the forbidden and the optimum crystallographic variant of rutile in garnet

On the critical structural factors dictating the selection of optimum COR in the structurally complicated system, such as the rutile-garnetsystem.

more ...
Journal logoJournal of Synchrotron Radiation Journal of
Synchrotron Radiation

Accepted 13 September 2016

Automatic crystal centring procedure at the SSRF macromolecular crystallography beamline

An automatic crystal centring procedure is reported, which is extremely effective under fluctuating light states as well as for poorly frozen and opaque samples at macromolecular crystallography beamlines.

Accepted 9 September 2016

Effect of gamma irradiation on X-ray absorption and photoelectron spectroscopy of Nd-doped phosphate glass


Accepted 5 September 2016

High-temperature tensile cell for in situ real-time investigation of carbon fibre carbonization and graphitization processes

A unique high-temperature cell combined with in situ wide-angle X-ray diffraction was used to follow the formation of graphitic structure in carbon fibre produced from a polyacrylo­nitrile precursor.

Accepted 29 August 2016

Nanox: a miniature mechanical stress rig designed for near-field X-ray diffraction imaging techniques

A compact design for a miniature tensile stress rig, compatible with the space and weight constraints imposed by near-field diffraction imaging techniques, is presented. The device can carry tensile loads up to 500 N and is driven by a piezoelectric actuator which can work in a static and dynamic regime up to frequencies of 100 Hz.

Accepted 29 August 2016

Kirkpatrick–Baez scanning of X-ray beam for Laue microdiffraction on accelero-phobic samples: application to in situ mechanically loaded nanowires


Accepted 24 August 2016

Augmentation of the step-by-step Energy-Scanning EXAFS beamline BL-09 to continuous-scan EXAFS mode at INDUS-2 SRS

An innovative scheme to carry out continuous X-ray absorption spectroscopy measurements similar to quick-EXAFS mode at the step-by-step Energy-Scanning EXAFS beamline BL-09 at the INDUS-2 synchrotron source is presented.

Accepted 22 August 2016

Design and performance of BOREAS, the beamline for resonant X-ray absorption and scattering experiments at the ALBA synchrotron light source

BOREAS is a beamline operating at the ALBA Synchrotron Light Source, dedicated to resonant X-ray absorption and scattering experiments using soft X-rays, in an unusually extended photon energy range from 80 to >4000 eV, with full polarization control. Here its optical scheme and the first commissioning results are described.

Accepted 19 August 2016

A high-accuracy complex-phase method of simulating X-ray propagation through a multi-lens system


Accepted 19 August 2016

Using irregularly spaced current peaks to generate an isolated attosecond X-ray pulse in free-electron lasers

A method is proposed to generate an isolated attosecond X-ray free-electron laser pulse with the peak power beyond 1 TW.

Accepted 18 August 2016

Creating flat-top X-ray beams by applying surface profiles of alternating curvature to deformable piezo bimorph mirrors

A piezo bimorph mirror is deformed into three distinct re-entrant surface modifications as well as being simply defocused. A re-entrant modification with seven segments (the maximum possible for this mirror) produces an expanded beam with less striation than a simply defocused beam.

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Journal logoIUCrData
IUCrData

Accepted 22 September 2016

(3Z)-5-Chloro-3-(hy­droxy­imino)­indolin-2-one

The crystal structure of 5-chloro­isatin 3-oxime is reported. The almost planar mol­ecules are connected by N—H⋯O inter­actions into dimers, graph-set motif R_{2}^{2}(8), and by O—H⋯O inter­actions into chains with a C(6) motif. A two-dimensional hydrogen-bonded polymer along [100] can be assumed.

Accepted 22 September 2016

Methyl 2-phenyl­quinoline-4-carboxyl­ate

Two independent mol­ecules, differing in the rotational orientation of the phenyl ring, comprise the asymmetric unit. π–π stacking inter­actions between the heterocyclic rings form stacks of mol­ecules approximately parallel to the b axis.

Accepted 22 September 2016

(E)-2-[(2,3-Di­bromo­all­yl)sulfan­yl]-1-methyl-1H-imidazol-3-ium bromide

The synthesis and crystal structure of the title imidazolium salt are reported.

Accepted 21 September 2016

(E)-3-(2,3-Di­meth­oxy­phen­yl)-1-(2-hy­droxy-5-meth­oxy­phen­yl)prop-2-en-1-one

In the chalcone derivative (E)-3-(2,3-di­meth­oxy­phen­yl)-1-(2-hy­droxy-5-meth­oxy­phen­yl)prop-2-en-1-one, the dihedral angle formed by the planes of the benzene rings is 29.6 (2)° and an intra­molecular O—H⋯O hydrogen bond closes an S(6) ring. Weak C—H⋯O hydrogen bonds link mol­ecules into chains propagating along [001].

Accepted 20 September 2016

{6,6′-Di­methyl-2,2′-bis­[(2-oxido­benzyl­idene)amino]-1,1′-bi­phenyl-κ4O,N,N′,O′}bis­(propan-2-olato-κO)titanium(IV) n-hexane hemisolvate

In the crystal structure of the title compound, the TiIV atoms are coordinated by a dianionic tetra­dentate Schiff base ligand and two O atoms of two isopropoxide anions, forming a distorted octa­hedral coordination sphere.

Accepted 16 September 2016

tert-Butyl 2,3-di­hydro-1H-cyclo­penta­[b]indole-4-carboxyl­ate

The title mol­ecule is essentially planar and contains one of the three methyl groups from the tert-butyl group within the plane. A mirror plane through the plane of the mol­ecule allows the third methyl group outside the plane to be symmetrically generated opposite the second one.

Accepted 16 September 2016

2-Methyl-N-(pyrazin-2-yl)propanamide 1,2,4,5-tetra­fluoro-3,6-di­iodo­benzene (2/1)

Pyrazine compounds have received considerable inter­est from organic chemists due to their large reactivity. The title compound was obtained by reaction of 2-amino­pyrazine with isobutyryl chloride. In the crystal, mol­ecules are connected by I⋯N halogen bonds.

Accepted 15 September 2016

4-{(1E,3E)-4-[4-(Di­methyl­amino)­phen­yl]buta-1,3-dien-1-yl}-1-methyl­pyridin-1-ium iodide

The asymmetric unit of the title mol­ecular salt comprises a pyridinium cation and an I anion. The cation exists in an E,E conformation with respect to the two C=C bonds, and is relatively planar with the pyridinium ring being inclined to the benzene ring by 10.8 (2) °.

Accepted 12 September 2016

(4Z)-1-Benzyl-4-(2-oxo­propyl­idene)-2,3,4,5-tetra­hydro-1H-1,5-benzodiazepin-2-one

The title compound, C19H18N2O2, crystallizes with two independent mol­ecules in the asymmetric unit which differ significantly in conformation. The two mol­ecules are linked via C—H⋯O hydrogen bonds, forming dimers which pack in rows approximately parallel to the c axis.

Accepted 9 September 2016

2-(6-Methyl-1-benzo­furan-3-yl)acetic acid

The asymmetric unit of the title compound, contains two crystallographically independent mol­ecules (A and B) with nearly matching conformations [r.m.s. overlay fit for the non-hydrogen atoms = 0.011 (1) Å]. The two mol­ecules are linked by a pair of O—H⋯O hydrogen bonds, enclosing an R_{2}^{2}(8) ring motif, and forming an AB dimer.

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