issue contents

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

December 2019 issue

Highlighted illustration

Cover illustration: Automation of both hardware and software plays an increasingly significant role in crystallography and can bring both advantages and pitfalls. One of the supposed selling points of the automation of crystal-structure-determination software is that it removes the need for crystallographic expertise. This means that potential problems may lie undiscovered, and the new structure may be defective in some way or misleading. One consequence of increasing automation in crystallography is the dilution or even the loss of knowledge and understanding of fundamental principles and key practices that have been generated in the past and are now being learnt and applied by fewer scientists. Aspects of this erosion of crystallographic expertise and the contribution of automation were addressed at a recent microsymmposium entitled `Teaching new dogs old tricks' at the 2019 ECM in Vienna. The article entitled `Some reflections on symmetry: pitfalls of automation and some illustrative examples' is the first report from that symposium. It illustrates how an understanding of the many aspects of symmetry can prevent mistakes that may be made by reliance on automatic procedures. Other topics addressed here include pseudo-symmetry, twinning, real and apparent disorder, chirality and structure validation. See: Clegg [Acta Cryst. (2019). E75, 1812-1819].

research communications


link to html
An outline is given of some basic concepts and applications of symmetry in crystallography. Three specific examples of structure determinations are discussed, for which an understanding of these aspects of symmetry avoids mistakes that can readily be made by reliance on automatic procedures. Topics addressed include pseudo-symmetry, twinning, real and apparent disorder, chirality, and structure validation.

link to html
In the title com­pound, the S atom is attached equatorially to the sugar ring. The C—S bond lengths are unequal. In the crystal, a system of three weak hydrogen bonds, sharing an oxygen acceptor, links the mol­ecules to form chains propagating parallel to the b-axis direction.

link to html
A mol­ecular compound with an unsupported Ir—Zn bond: [Cp*(PMe3)2Ir]-[ZnI2] (Cp*=cyclo-C5Me5), is reported as its benzene solvate.

link to html
A benzo­quinone com­pound was unintentionally synthesized by photocyclization and subsequent oxidation in air while attempting to transform the E isomer of a nicotinamide derivative to its Z isomer. The chemical and mol­ecular structures of the product was established crystallographically. The surprising synthesis, chromatographic purification and com­prehensive characterization of this com­pound including single crystal structural analysis are reported and its structure including crystal packing is discussed in detail.

link to html
An organically pillared EuIII–oxalate–carboxyl­ate framework structure with [Eu(NH2—BDC)(ox)(H3O)] topology is reported. The non-porous three-dimensional structure is constructed from two-dimensional layers of EuIII–carboxyl­ate–oxalate, which are pillared by NH2—BDC2− pillars. The basic structural unit of the layer is an edge-sharing dimer of TPRS-{EuIIIO9}, which is assembled through the ox2− moiety. The intra­layer void is partially occupied by TPR-{EuIIIO6} motifs.

link to html
The structure of catena-[tris­(μ4-benzene-1,4-di­carboxyl­ato)-tetra­kis­(μ1– di­methyl­formamide-κ1O)-trinickel(II)], C36H40N4Ni3O16, has been determined in the monoclinic P21/n space group. The compound has a two-dimensional coordination network structure and it is of inter­est with respect to lithium-ion battery applications. Hirshfeld surface analysis was performed to characterize inter­planar inter­actions. The structure exhibits disorder of coordinated solvent mol­ecules.

link to html
The diffraction data confirmed the title compound as the main isomer produced in a coupling reaction. The structure and Hirshfeld surface analysis of the formed di-tetra­zolyl chelate ligand are reported.

link to html
The reaction of t-Bu2Si(OH)2 with two equivalents of Cp2Zr(CH3)2 produces the t-Bu2SiO2-siloxide bridged dimer where one methyl group is retained per zirconium atom. The retention of one methyl group per metal center affords a site for further reactivity.

link to html
The title compound was analysed as a disordered structure over two states, viz. co-crystal and salt, accompanied by a keto–enol tautomerization in the base mol­ecule. In the compound, the acid and base mol­ecules are linked by a short hydrogen bond [O⋯O = 2.4393 (15) Å], in which the H atom is disordered over two positions with equal occupancies.

link to html
The ZnII ion lies on a crystallographic twofold axis and has distorted tetra­hedral coordination geometry. Two weak C—H⋯S intra­molecular hydrogen bonds exist between the bipyridyl and thiol groups. In the crystal, mol­ecules are linked by weak C—H⋯O and C—H⋯S hydrogen bonds, forming a three-dimensional supra­molecular architecture.

link to html
In the title 1,4-di­hydro­pyridine derivative, the 1,4-di­hydro­pyridine ring makes an angle of 82.19 (13)° with the thio­phene ring. In the crystal, N—H⋯O and C—H⋯O hydrogen bonds as well as C—H⋯π inter­actions link the mol­ecules into a three-dimensional network.

link to html
A new polymorphic form of 3-acetyl-8-meth­oxy-2H-chromen-2-one is described and compared with the previously reported polymorph. In the crystal, hydrogen bonds, π–π inter­actions and anti­parallel C=O⋯C=O inter­actions give rise to a helical supra­molecular architecture

link to html
K2Pt(CN)4 becomes soluble in di­chloro­methane upon addition of two equivalents of 18-crown-6. Crystals of [K(18-crown-6)]2 [Pt(CN)4] are obtained upon layering the di­chloro­methane solution with di­ethyl­ether. No Pt⋯Pt inter­actions are observed in the crystal.

link to html
The crystal structure of the title compound consists of discrete negatively charged [Cr(NCS)4(pyridine)2] complexes that are charge balanced by pyridinium cations and contains additional pyridine solvent mol­ecules that are linked by weak C—H⋯S hydrogen bonding into a three-dimensional network.

link to html
In the crystal, the mol­ecules are linked by N—H⋯O and C—H⋯O inter­actions, forming a three-dimensional network. The theoretical geometrical parameters are in good agreement with XRD results.

link to html
A jatrophane diterpenoid was isolated from the fructus of Euphorbia sororia and its structure and absolute configuration have been established by X-ray crystallographic analysis.

link to html
The crystal structures of two new forms of cobalt–pyridine–sulfate complexes are presented. The feature infinite chains of metal–pyridine units connected by bridging sulfate anions, which are distinct from the only previously reported structure of a cobalt–pyridine–sulfate compound.

link to html
The crystal structure of the complex {Eu[O2P(O-2,6-iPr2C6H3)2]3(CH3OH)5}·CH3OH, which exhibits intra- and inter­molecular O—H⋯O hydrogen bonding, and its luminescent properties have been studied.

link to html
The crystal structure of (NH4)3Al2(PO4)3 was refined by powder XRD synchrotron data. (NH4)3Al2(PO4)3 is a member of the structural family with formula A3Al2(PO4)3 where A is a group 1 element, of which the K and Rb forms are also known.

link to html
The title compound, [(OC)2Fe(μ-dppm)(μ-C(=O)C(2,4,5-C6H2Me3)= CH)Pt(PPh3)], represents an example of a diphosphane-bridged heterobimetallic dimetalla­cyclo­pentenone complex resulting from a bimetallic activation of 1-ethynyl-2,4,5-tri­methyl­benzene and a metal-coordinated carbonyl ligand.

link to html
Two biologically active compounds were synthesized and their crystal structures were determined. The characteristic feature of both structures is mol­ecular layers in the crystal lattice formed via C—H⋯O and O—H⋯O inter­actions. The mol­ecular Hirshfeld surfaces analysis were explored with two-dimensional fingerprint plots for the title compounds and other known structures from the literature. Additionally, the lipophilicity parameters (logP) were determined and related to the C⋯H contact contribution in the Hirshfeld surface.

link to html
In the title compound, the central FeII ion is coordinated by four pyrrole N atoms of the porphyrin core and two C atoms of the cyano groups in a slightly distorted octa­hedral coordination environment. The complex mol­ecule has a distorted porphyrin core.

link to html
The mean planes of the phenyl and triazole rings are nearly perpendicular to one another as a result of the intra­molecular C—H⋯O and C—H⋯π(ring) inter­actions. In the crystal, layers parallel to (101) are generated by O—H⋯N, N—H⋯O and N—H⋯N hydrogen bonds. The layers are connected by inversion-related pairs of C—H⋯O hydrogen bonds.

link to html
In the title compound, the phenyl and pyridazine rings are inclined to each other by 10.55 (12)°, whereas the 4-methyl­benzyl ring is nearly orthogonal to the pyridazine ring with a dihedral angle of 72.97 (10)°.

link to html
In the title Schiff base derivative carrying a 2-bromo-3-methyl­phenyl group, the conformation about the C=N bond is E. In the crystal, O—H⋯O hydrogen-bond inter­actions consolidate the crystal packing. A Hirshfeld surface analysis and fingerprint plots were used to further investigate the inter­molecular inter­actions in the solid state.

link to html
The synthesis of a hybrid mol­ecule is reported. The crystal structure of the monohydrate was investigated using Hirshfeld surface analysis and enrichment contact ratios. Hydrogen bonds induced by guest water mol­ecules are the main driving force in crystal packing formation.

link to html
The di­hydro­benzimidazol-2-one moiety is essentially planar with the prop-2-yn- 1-yl substituent rotated well out of this plane. In the crystal, C—H⋯π(ring) inter­actions and C—H⋯O hydrogen bonds form corrugated layers parallel to (10\overline{1}), which are associated through additional C—H⋯O hydrogen bonds and head-to-tail, slipped, π-stacking inter­actions between di­hydro­benzimidazol-2-one moieties

link to html
A triclinic polymorph of 1,4-bis­([2,2′:6′,2′′-terpyridin]-4′-yl)benzene was obtained under solvothermal conditions.

addenda and errata


Research communications

Research communications are designed to help authors bring out the science behind their structure determinations. Authors are encouraged to report more than one structure in the same communication and also to include the results of investigations with other techniques. The Research communications format makes Acta E the natural home for structure determinations with interesting science to report.

Emerging Sources Citation Index

Acta E is included in the Emerging Sources Citation Index.

ESCI

Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds