forthcoming articles

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

IUCrJ
Accepted 17 July 2019

Charge densities in actinide compounds: strategies for data reduction and model building

We present a three part paper on charge density analysis of actinide containing compounds – experimental protocols, augmented multipole model building, and comparison of topological analysis of experimental and theoretical electron densities.

Accepted 2 July 2019

Structural insights into stressosome assembly

Stressosome assembly mediated by the STAS domain was analyzed based on the crystal structure of RsbS and the cryo-EM structure of the RsbS–RsbRA complex.

Accepted 27 June 2019

Spin resolved electron density study of YTiO3 in its ferromagnetic phase: signature of orbital ordering

The first joint refinement against X-ray and polarized neutron diffraction data performed to simultaneously model the charge and spin density of the perovskite YTiO3 in its ferromagnetic state is presented. The resulting model confirms the orbital ordering at low temperature.

Accepted 25 June 2019

1 kHz fixed-target serial crystallography using a multilayer monochromator and an integrating pixel detector

1 kHz fixed-target serial crystallography using polychromatic X-rays and a novel JUNGFRAU detector allows the recording of a complete diffraction dataset in 30 s.

Accepted 19 June 2019

Resolution and dose dependence of radiation damage in biomolecular systems

Data from several radiation-damage studies using protein crystals are reanalyzed to determine the local dose- and resolution-dependent decay of diffracted intensity at T = 100 K. The results are inconsistent with long-accepted models and with a proposed linear scaling between maximum tolerable dose and resolution, but are reproduced by a simple, physics-based model.
Journal logoActa Crystallographica Section A
Acta Crystallographica
Section A
FOUNDATIONS AND ADVANCES

Accepted 21 June 2019

Using the singular value decomposition to extract 2D correlation functions from scattering patterns

We apply the truncated singular value decomposition (TSVD) to extract the underlying 2D correlation functions from small-angle scattering patterns.

Accepted 19 June 2019

Local and Global Color Symmetries of a Symmetrical Pattern

Given a symmetrical pattern {\cal P} consisting of disjoint congruent symmetric motifs, we discuss a method in arriving at a coloring of {\cal P} which is perfect and transitive under its global symmetry group G; and where the coloring of each motif is also perfect and transitive under its own group of symmetries, referred to as local symmetries of {\cal P}. The coloring of {\cal P} is coordinated with the property that the symmetry of {\cal P} that is both a global and local symmetry, effects the same permutation of the colors of {\cal P} and the corresponding motif, respectively.

Accepted 17 June 2019

Algorithm for distance list extraction from pair distribution functions

The atomic pair distribution function (PDF) represents the structure of a material as a list of distances between pairs of atoms. This paper presents an algorithm that can extract the distance list from a measured PDF in a highly automated manner without prior knowledge of the structure.

Accepted 17 June 2019

A new method for in situ structural investigations of nano-sized amorphous and crystalline materials using mixed-flow reactors

A novel method is introduced for in situ X-ray total scattering experiments. Two examples of the method as applied to non-classical nucleation and crystal growth studies are discussed.

Accepted 13 June 2019

Anomalous X-ray diffraction from ω nanoparticles in β-Ti(Mo) single crystals

Anomalous X-ray diffraction was used to study the energy dependence of diffuse scattering around the reciprocal-lattice point {\bf h} = [006]_\beta \equiv [06{\overline 6}3]_\omega of a Ti–15Mo single crystal. The diffuse scattering as well as its energy dependence around a Mo K absorption edge were qualitatively explained by a numerical model of ω particles which elastically deform the surrounding β matrix.

Accepted 6 June 2019

Coordination shells and coordination numbers of the vertex graph of the Ammann–Beenker tiling

A growth form and an asymptotic formula for the coordination sequence of the vertex graph of the Ammann–Beenker tiling are obtained.

Accepted 6 June 2019

Robust minimal matching rules for quasicrystals

An algorithmic procedure is proposed for extraction of physically meaningful matching rules directly from the phased diffraction data of a quasicrystal.

Accepted 4 June 2019

Relativistic quantum crystallography of di­phenyl- and di­cyanomercury. Theoretical structure factors and Hirshfeld atom refinement

Contributions of different physical effects (thermal smearing, relativity, electron correlation, basis set, environment and/or atomic contributions) to the structure factors of heavy-element compounds are inspected. Relativistic Hirshfeld atom refinement yields an almost perfect agreement with reference geometries in this theoretical pilot study, showing the usefulness of the employed methodology.

Accepted 14 May 2019

A Journey into Reciprocal Space: A Crystallographer's Perspective

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

Accepted 2 July 2019

Insight into the role of pre-assembly and desolvation in crystal nucleation: a case of p-nitro­benzoic acid

The pathway and hybrid control mechanism of crystal nucleation were studied through both experimental and computational investigation on the role of pre-assembly and desolvation in nucleation process.

Accepted 29 June 2019

Analytical description of nanowires. I. Regular cross sections for zincblende and diamond structures

Regular cross sections of zincblende- and diamond-structured nanowires (NWires) are described, and number series are presented for NWire atoms, for the bonds between these and for the NWire interface bonds for a slab of unit-cell length along the NWire axis, as well as the characteristic lengths and areas of the NWire cross sections. The ratios of internal bonds per NWire atom, of internal to interface bonds and of interface bonds per NWire atom present fundamental tools to interpret any spectroscopic data which depend on the diameter and cross-sectional shape of NWires.

Accepted 28 June 2019

Octahedral tilting in the polar hexagonal tungsten bronzes RbNbW2O9 and KNbW2O9

The first powder neutron diffraction study of the hexagonal tungsten bronzes RbNbW2O9 and KNbW2O9. We report the existence of octahedral tilting that has not been previously observed using X-ray diffraction.

Accepted 28 June 2019

A commensurately modulated crystal structure and physical properties of novel polymorph of the caesium manganese phosphate, CsMnPO4

A new modification of CsMnPO4 (β – phase) is discussed in a superspace approach. Structural relations with topologically and chemically similar compounds are shown.

Accepted 26 June 2019

Problems in Structural Inorganic Chemistry. Second edition


Accepted 26 June 2019

Stimuli-responsive aggregation-induced fluorescence in a series of bi­phenyl-based Knoevenagel products: effects of substituent active methyl­ene groups on π–π interactions

A photophysical study involving three bi­phenyl-based Knoevenagel products has been carried out. Two of the compounds show stimuli-responsive aggregation-enhanced emission. Photophysical behavior of the active fluoro­phore is explained based on molecular packing and π–π interactions.

Accepted 26 June 2019

Understanding the formation of apremilast cocrystals

In investigating the formation of apremilast cocrystals, this work demonstrates the preference for aromatic–aromatic interactions over hydrogen bonds in the studied crystals and the stabilizing role of disorder, leading to entropy-driven formation of the cocrystals.

Accepted 25 June 2019

The Na—O bond in sodium fenamate

The Na—O bonds are very weak, comparable with the weak N—H⋯O intramolecular hydrogen bond. The polymeric structure is stabilized by the interaction of the sodium cation with the surrounding water molecules.

Accepted 14 June 2019

From space group to space groupoid: the partial symmetry of low-temperature E-vanillyl oxime

The partial symmetry of low-temperature E-vanillyl oxime is analysed using space groupoids.

Accepted 14 June 2019

Rb2CaCu6(PO4)4O2, a novel oxophosphate with a shchurovskyite-type topology: synthesis, structure, magnetic properties and crystal chemistry of rubidium copper phosphates

A novel compound, Rb2CaCu6(PO4)4O2, was synthesized by a hydrothermal method and characterized as the shchurovskyite-type structure, based upon a heteropolyhedral copper phosphate framework. Microscopic calculations are indicative of possible low-dimensional magnetic behavior, as they confirm weak magnetic coupling between the copper-based layers mediated by the Cu–Cu pairs.

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Journal logoActa Crystallographica Section C
Acta Crystallographica
Section C
STRUCTURAL CHEMISTRY

Accepted 16 July 2019

Effect of pH on the construction of CdII coordination polymers involving the 1,1′-[1,4-phenyl­ene­bis­(methyl­ene)]bis­(3,5-di­carboxyl­atopyridinium) ligand

Two new coordination polymers based on 1,1′-[1,4-phenyl­enebis(methyl­ene)]bis­(3,5-di­carboxyl­atopyridinium) (L2−) have been prepared and structurally characterized. In one polymer, CdII ions are linked by bidentate L2− ligands to form a one-dimensional polymer, while in the other polymer, CdII ions are bridged by hexa­dentate L2− ligands to form a three-dimensional polymer.

Accepted 14 June 2019

Three new acid M+ arsenates and phosphates with multiply protonated As/PO4 groups

The crystal structures of Cs(H2AsO4)(H3AsO4)2, NH4(H2AsO4)(H3AsO4) and Li2(H2PO4)2 were determined from single-crystal X-ray diffraction data. The two alkali compounds represent novel structure types, while the ammonium compound is homeotypic with its Rb analogue.
Journal logoActa Crystallographica Section D
Acta Crystallographica
Section D
STRUCTURAL BIOLOGY

Accepted 16 July 2019

Nonmerohedral twinning: from minerals to proteins

Examples are presented of successful data processing, phasing and refinement strategies for non-merohedral twins, covering the range from minerals to proteins.

Accepted 12 July 2019

Structural comparison of protiated, H/D-exchanged and deuterated human carbonic anhydrase IX

In this work, the X-ray crystal structures of four different deuterium-labelled versions of a surface variant of human carbonic anhydrase IX are compared and discussed. The results show that the overall structure and active-site organization of each version are essentially the same, paving the way for future neutron protein crystallography studies.

Accepted 10 July 2019

Location-specific qu­antification of protein-bound metal ions by X-ray anomalous dispersion: Q-XAD

This article describes a method for the quantification of relative amounts of different metal ions in binding sites of metalloproteins by X-ray anomalous dispersion.

Accepted 8 July 2019

Structures of major pilins in Clostridium perfringens demonstrate dynamic conformational change

Pili, polymers of the major pilin, in Gram-positive bacteria are flexible rod proteins associated with the bacterial cell surface that play important roles in initial adhesion to host tissues and colonization. Crystal structures of major pilins from C. perfringens strains have been determined, which were considered to be in an equilibrium state between an elongated and a bent structure through dynamic conformational change.

Accepted 3 July 2019

A novel structurally characterized haloacid dehalogenase phosphatase from Thermococcus thioreducens with diverse substrate specificity

A new haloacid dehalogenase (HAD) phosphatase originating from T. thioreducens was expressed, purified and crystallized, and its structure was refined to 1.75 Å resolution. Structural studies confirmed the presence of the canonical HAD phosphatase fold with the HAD signature motifs and of Mg2+ ion in the active site. The results of computational docking and enzymatic assays identified possible substrates of the enzyme.

Accepted 3 July 2019

Biochemical and structural explorations of α-hydroxyacid oxidases reveal a four-electron oxidative de­carboxylation reaction

Structural and enzymological explorations of α-hydroxyacid oxidases uncover new flavin mononucleotide-mediated reactions and intermediates.

Accepted 30 June 2019

Sequence assignment for low-resolution modelling of protein crystal structures

Recent advances in automated protein model building using ARP/wARP are presented. The new methods include machine-learning-enhanced sequence assignment and loop building using a fragment database.

Accepted 22 June 2019

Prediction of models for ordered solvent in macromolecular structures by a classifier based upon resolution-independent projections of local feature data

PeakProbe facilitates the automated modelling of ordered solvent in macromolecular crystal structures by analysing features of the electron density and chemical environment surrounding a given coordinate. The extracted data are transformed to a resolution-independent score space and likely solvent models are predicted based on the frequency distributions observed in a large-scale sample of the PDB.
Journal logoActa Crystallographica Section E
Acta Crystallographica
Section E
CRYSTALLOGRAPHIC COMMUNICATIONS

Accepted 20 July 2019

A molybdenum tris­(di­thiol­ene) complex coordinates to three bound cobalt centers in three different ways

A molybdenum tris­(di­thiol­ene) complex acts as a ligand towards three Co(CO)2 units.

Accepted 20 July 2019

Syntheses and structures of piperazin-1-ium ABr2 (A = Cs or Rb): hybrid solids containing `curtain wall' layers of face- and edge-sharing ABr6 trigonal prisms

The isostructural title compounds feature striking layers of ABr6 (A = Cs, Rb) trigonal prisms sharing faces and edges.

Accepted 19 July 2019

Syntheses and crystal structures of a new family of hybrid perovskites: C5H14N2·ABr3·0.5H2O (A = K, Rb, Cs)

The isostructural title compounds are a new family of hybrid perovskite hemihydrates.

Accepted 18 July 2019

2-Methyl-4-(4-nitro­phen­yl)but-3-yn-2-ol: crystal structure, Hirshfeld surface analysis and computational chemistry study

In the title mol­ecule, di-methyl­hydroxy and 4-nitro­benzene groups cap a central di-substituted acetyl­ene residue. The extended structure features flattened, hexa­meric clusters sustained by hy­droxy-O—H⋯O(hy­droxy) hydrogen bonds.

Accepted 18 July 2019

Crystal structure of tetra-μ-acetato-bis­[(5-amino-2-methyl­sulfanyl-1,3,4-thia­diazole-κN1)copper(II)]

The reaction of 2-methyl­thio-5-amino-1,3,4-thia­diazole with copper(II) acetate monohydrate resulted in the formation of the title binuclear compound

Accepted 18 July 2019

Crystal structure and Hirshfeld surface analysis of 2,5-di­bromo­terephthalic acid ethyl­ene glycol monosolvate

The crystal structure of the title mol­ecular solvate features O—H⋯O hydrogen bonds, Br⋯O and π–π inter­actions. Hirshfeld surface analysis and fingerprint plots helped to identify the major contributors to the inter­molecular inter­actions.

Accepted 12 July 2019

(3,5-Di­methyl­adamantan-1-yl)ammonium methane­sulfonate (memanti­nium mesylate): synthesis, structure and solid-state properties

The title salt crystallizes with three independent ionic pairs in the asymmetric unit. In the crystal, (3,5-di­methyl­adamantan-1-yl)ammonium cations and methane­sulfonate anions associate via N—H⋯O hydrogen bonds into layers that extend parallel to (001) and comprise large supra­molecular hydrogen-bonded rings.
Journal logoActa Crystallographica Section F
Acta Crystallographica
Section F
STRUCTURAL BIOLOGY COMMUNICATIONS

Accepted 15 July 2019

Co-crystal structure of the iMango-III fluorescent RNA aptamer using an X-ray free-electron laser

The iMango-III aptamer is demonstrates one of the largest fluorescence enhancements of all RNA aptamers. Here. the room-temperature crystal structure of the iMango-III aptamer determined using an X-ray free-electron laser is reported.

Accepted 9 July 2019

AMi: a GUI-based, open-source system for imaging samples in multi-well plates

Described here are instructions for building and using an inexpensive automated microscope that is driven by a dedicated graphical user interface. The system facilitates the automated imaging and manual inspection of multi-well plates.

Accepted 8 July 2019

Crystal structure of the Saccharomyces pombe U7BR E2-binding region in complex with Ubc7

A 1.7 Å resolution co-crystal structure of U7BR from S. pombe in complex with Ubc7 is reported. Structural comparisons and biochemistry suggest that U7BR presents a steric impediment to E1 binding and inhibits E1-mediated charging, respectively.
Journal logoJournal of Applied Crystallography Journal of Applied
Crystallography

Accepted 18 July 2019

A comparison of gas stream cooling and plunge cooling of macromolecular crystals

Gas stream cooling at 100 K is found to yield lower mosaicity than plunge cooling into liquid nitro­gen at 77 K for several different protein crystals.

Accepted 17 July 2019

Single-crystal time-of-flight neutron Laue methods: application to manganese catalase from Thermus thermophilus HB27

Time-of-flight neutron diffraction of a manganese catalase cubic crystal with a = 133 Å was successfully performed using the IBARAKI biological crystal diffractometer.


Accepted 8 July 2019

A New Algorithm for the Reconstruction of Protein Molecular Envelopes from X-ray Solution Scattering Data

A method is described for reconstructing the shapes of protein molecules from X-ray solution scattering data that involves the progressive confinement of a set of interacting volume-defining points to fit the expected protein volume. Tests with synthetic and experimental data demonstrate that the final distributions of points obtained using this approach correctly map out the protein envelope.

Accepted 3 July 2019

Crystallographic orientation of primary and eutectic phases in a hypoeutectic Mn–Sb alloy induced by solidification in high magnetic fields

Solidifying in high magnetic fields is an effective way to control the crystallographic orientation of the primary and eutectic phases in a binary eutectic alloy.

Accepted 2 July 2019

Shock Wave induced Nucleation leading to Crystallization in Water

Several research articles are available to understand the crystallization of super cooled under shock waves. From our best of literature survey this is first report for achieving the crystallization un-saturated condition for liquids.

Accepted 1 July 2019

Crystallography at the nanoscale: planar defects in ZnO nanospikes

Cross-section analysis of defects in ZnO nanospikes by means of transmission electron microscopy and defect simulation.

Accepted 29 June 2019

Correlative vibrational spectroscopy and 2D-XRD to probe the mineralization of bone in phosphate deficient mice

2D-XRD and vibrational spectroscopy are used to follow changes in bone remodelling due to different health conditions (pregnancy, lactation) and bone pathologies (phosphate deficiency) in mice.

Accepted 29 June 2019

Crystal structure of Mo-substituted lanthanum tungstate La5.4W1-yMoyO12-δ (0 ≤ y ≤ 0.2) studied by X-ray and neutron diffraction

This work describes in detail the crystal structure of Mo-substituted lanthanum tungstates through neutron diffraction and high-resolution X-ray diffraction as a function of temperature between T = 10 K and T = 298 K. Combined X-ray and neutron diffraction refinements and electron probe micro-analysis were employed to locate Mo atoms in the crystal structure of La5.4W1-yMoyO12-δ (0 ≤ y ≤ 0.2).

Accepted 29 June 2019

A robust Expectation-Maximization method for the interpretation of small angle scattering data on dense nanoparticle samples

This paper presents a robust method for the resolution of SAS problems featuring a structure factor. It is based on the Local Monodisperse Approximation and the Expectation-Maximization algorithm.

Accepted 27 June 2019

Small-angle neutron scattering (SANS) and spin-echo SANS measurements reveal the logarithmic fractal structure of the large-scale chromatin organization in HeLa nuclei


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Journal logoJournal of Synchrotron Radiation Journal of
Synchrotron Radiation

Accepted 28 June 2019

Reducing sample consumption for serial crystallography using acoustic drop ejection

A new approach for efficiently loading fixed targets for serial crystallography using acoustic dispensing is presented.

Accepted 17 June 2019

Simultaneous scanning near-field optical and X-ray diffraction microscopy for correlative nanoscale structure–property characterization

A multimodal imaging instrument has been developed that integrates scanning near-field optical microscopy with nanofocused X-ray diffraction imaging. The instrument allows for simultaneous, site-correlated characterizations of electronic and near-field optical properties of materials together with their crystallographic structure with nanoscale resolutions.

Accepted 13 June 2019

Effect of the third undulator field harmonic on spontaneous and stimulated undulator radiation


Accepted 7 June 2019

Soft X-ray varied-line-spacing gratings fabricated by near-field holography using an electron beam lithography-written phase mask

A method comprising near-field holography with an electron beam lithography-written phase mask was developed herein. Soft X-ray varied-line-spacing gratings with a central groove density greater than 3000 lines mm−1 were fabricated using this method.

Accepted 3 June 2019

Kirkpatrick–Baez active optics system at FERMI: system performance analysis

The present work reports on the final results of the upgraded Kirkpatrick–Baez active optics systems (KAOS), which have been mechanically modified in order to work with better stability and repeatability with respect to the original design. The results have been obtained on both the FERMI FEL lines, FEL1 and FEL2, and are particularly relevant for the latter as it is the low-wavelength line recently opened to users.

Accepted 2 June 2019

Revealing phase boundaries by weighted parametric structural refinement

This study outlines a weighted parametric Rietveld refinement technique for revealing subtle phase boundaries.

Accepted 1 June 2019

X-ray reflecto-interferometer based on compound refractive lenses

An X-ray amplitude-splitting interferometer based on compound refractive lenses, which operates in the reflection mode, is proposed and realized.

Accepted 30 May 2019

Method of calculating the aberrations of soft X-ray and vacuum ultraviolet optical systems

Soft X-ray and vacuum ultraviolet (XUV) optical systems are widely used with synchrotron radiation, X-ray microscopy, etc. Here an aberrations analytical analysis method for XUV multi-element optical systems is proposed. It can calculate the contribution of different types of aberration, and thus will be helpful in the design and optimization of XUV multi-element optical systems.

Accepted 30 May 2019

Linear array detector for online diagnostics of spectral distributions at MHz repetition rates

The novel line detector KALYPSO has been developed for the measurement of one-dimensional profiles at high-repetition-rate free-electron lasers (FELs) and synchrotron radiation facilities. The current version has 256 pixels with a continuous data readout at a maximum frame rate of 2.7 MHz. At FLASH, KALYPSO has been utilized as photon diagnostics for monitoring pulse-resolved FEL spectra at a repetition rate of 1.0 MHz. KALYPSO is a collaborative effort between the Karlsruhe Institute of Technology (KIT), Paul Scherrer Institut (PSI), Lodz University of Technology (TUL-DMCS) and Deutsches Elektronen-Synchrotron (DESY).

Accepted 23 May 2019

XANES and EXAFS of dilute solutions of transition metals at XFELs

In this manuscript, we have demonstrated that X-ray absorption spectroscopy, both XANES and EXAFS, of solutions with millimolar concentrations of metal is possible using the femtosecond X-ray pulses from XFELs with two different sample delivery methods, a Rayleigh jet and a drop-on-demand setup

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Journal logoIUCrData
IUCrData

Accepted 22 July 2019

S-Di­ethyl­amino-S-(3-methyl­benzoyl­imino)-S,S-di­phenyl­sulfonium tetra­fluoro­borate

In the title mol­ecule, the configuration around the sulfur atom is a slightly distorted tetra­hedral geometry with two S—N bonds and two S—C bonds.

Accepted 20 July 2019

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

The central NiII ion has an N4O2 octa­hedral coordination sphere defined by two tridentate ligands: 2,2′:6′,2"-terpyridine and pyridine-2,6-di­carboxyl­ate anion.

Accepted 19 July 2019

(1,4,8,11-Tetra­aza­cyclo­tetra­deca­ne)palladium(II) diiodide monohydrate

The PdII ion has an N4 square-planar coordination sphere defined by a tetra­dentate 1,4,8,11-tetra­aza­cyclo­tetra­decane ligand.

Accepted 18 July 2019

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

In the title compound, weak N—H⋯N hydrogen bonds link the mol­ecules into [100] chains.

Accepted 18 July 2019

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

The title compound is an inter­mediate in the synthesis of the anti-HIV drug efavirenz. Its crystal structure is consolidated by N—H⋯F and N—H⋯O hydrogen bonds, which generate [010] chains.

Accepted 16 July 2019

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 contains a bridging dioxepine unit which hinders the rotation around the 2,2′-inter­naphthyl bond.

Accepted 12 July 2019

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

Solid-state structural analysis of 1-(2,4,6-tri­methyl­phen­yl)-3-(benz­yl)imidazole-2-silver(I) acetate reveals that the mol­ecule resides on an inversion center so that half of the mol­ecule is crystallographically unique. The binuclear complex mol­ecules display strong C—H⋯π inter­actions and strong π–π stacking inter­actions.

Accepted 9 July 2019

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

In the title compound the dihedral angle between the aromatic rings is 77.79 (8)°. Inversion dimers linked by pairs of N—H⋯N hydrogen bonds feature in the crystal structure.


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