N-Oxide–N-oxide inter­actions and Cl⋯Cl halogen bonds in penta­chloro­pyridine N-oxide: the many-body approach to inter­actions in the crystal state

In the crystal structure of penta­chloro­pyridine N-oxide, mol­ecules are linked by C—Cl⋯Cl halogen bonds into infinite ribbons extending along the crystallographic [100] direction. These mol­ecular aggregates are further stabilized by very short inter­molecular N-oxide–N-oxide inter­actions into herringbone motifs. Computations based on quantum chemistry methods allowed for a more detailed description of the N-oxide–N-oxide inter­actions and Cl⋯Cl halogen bonds.

High-pressure synthesis and crystal structure of the strontium tungstate Sr₃W₂O₉

The strontium tungstate Sr₃W₂O₉ was obtained using a high-pressure synthesis technique. The structure was found to be a hettotype structure of the high-pressure phase of Ba₃W₂O₉. One characteristic of the structure is the breaking of the threefold rotation symmetry existing in the high-pressure phase of Ba₃W₂O₉.

Tri­ethano­laminate iron perchlorate revisited: change of space group, chemical composition and oxidation states in [Fe₇(tea)₃(tea-H)₃](ClO₄)₂ (tea-H₃ is tri­ethano­lamine)

Reinvestigation of the literature structure of tri­ethano­laminate iron perchlorate results in a different space-group symmetry, different mol­ecular composition, different hydrogen bonding and different iron oxidation states.

Mixed Ca/Sr salt forms of salicylic acid: tuning structure and aqueous solubility

A series of mixed-metal Ca/Sr and Sr/Ba salts of salicylate is presented. The a and c axes increase in length with increasing amounts of the larger cations, but the b axis contracts slightly. The aqueous solubility of the Ca/Sr series increases with increasing Sr content.

Manganese(II), lead(II) and cadmium(II) coordination complexes containing a tetra­zole-based acyl­amide ligand: synthesis and the influence of the metal ions on the structures

Three coordination complexes based on N-(1H-tetra­zol-5-yl)cinnamamide have been synthesized, their structures determined and the influence of the metal ions on their structures explored.

Synthesis, crystal structure and biological properties of a cis-di­chlorido­bis­(di­imine)­copper(II) complex

A cis-di­chlorido­bis­(di­imine)­copper(II) complex has been synthesized and structurally characterized and its biological properties have been explored.

Formaldehyde–amino­guanidine condensation and amino­guanidine self-condensation products: syntheses, crystal structures and characterization

The ionic salts of diprotonated cations of 2,2′-methyl­enedihydrazinecarboximidamide and bis­guanidine have been prepared for the first time and characterized by X-ray diffraction and spectroscopic methods. The endothermic reaction involved in the thermal decomposition of the high-nitro­gen-content (49%) oxygen-containing former material requires additional oxygen.

A versatile synthesis of cyclic dipeptides using the stepwise construction of the piperazine-2,5-dione ring from simple precursors: synthetic sequence and the structure of a representative product, (3RS)-4-(2-allyl-3,5-di­methyl­phen­yl)-1-benzyl-3-phenyl­piperazine-2,5-dione

Multiply substituted cyclic dipeptides are synthesized using the stepwise construction of the piperazine-2,5-dione ring from four simple mol­ecular precursors. In (3RS)-4-(2-allyl-3,5-di­methyl­phen­yl)-1-benzyl-3-phenyl­piperazine-2,5-dione, the piperazine-2,5-dione ring adopts a boat conformation and the combined action of six independent hydrogen bonds links the mol­ecules into a three-dimensional array.

Synthesis, crystal structure and characterization of a three-dimensional Cd^II coordination polymer constructed from 2,5-bis­(1H-1,2,4-triazol-1-yl)terephthalate

A three-dimensional Cd^II coordination polymer with a (4,4)-connected topology was assembled from 2,5-bis­(1H-1,2,4-triazol-1-yl)terephthalic acid and Cd^II nitrate. The new complex shows enhanced and red-shifted photoluminescence with respect to the uncoordinated ligand.

Synthesis, crystal structure and photophysical properties of 1,4-bis­(1,3-di­aza­azulen-2-yl)benzene: a new π building block

Single-crystal X-ray analysis reveals that 1,4-bis­(1,3-di­aza­azulen-2-yl)benzene has a conjugated structure with 26-π electrons, indicating promising prospects of serving as a new π building block. In the crystal, the compound forms one-dimensional chains along the a axis through π–π inter­actions and adjacent chains are stabilized by C—H⋯N inter­actions to form a three-dimensional architecture.

The effect of amino acid backbone length on mol­ecular packing: crystalline tartrates of glycine, β-alanine, γ-amino­butyric acid (GABA) and DL-α-amino­butyric acid (AABA)

The effect of amino acid backbone length on mol­ecular packing has been studied using crystalline tartrates of glycine, β-alanine, γ-amino­butyric acid (GABA) and DL-α-amino­butyric acid (AABA) as examples.

Structure and electrical properties of a one-dimensional polymeric silver thio­saccharinate complex with argentophilic inter­actions

A one-dimensional polymeric silver thio­saccharinate complex displays an unusually short Ag⋯Ag distance of 2.8306 (9) Å. The crystal structure consists of weakly inter­acting columns. The complex behaves as a semiconductor, with a moderately low conductivity.

Higher hydrates of lithium chloride, lithium bromide and lithium iodide

The crystal structures of all higher hydrates of lithium halides have been determined. In each hydrate, the lithium cation is coordinated octa­hedrally. The dihydrates crystallize in the NaCl·2H₂O or NaI·2H₂O type structure. Surprisingly, in the tri- and penta­hydrates of LiCl and LiBr, one water mol­ecule per Li⁺ ion remains uncoordinated.

Synthesis and structures of six closely related N-[3-(2-chloro­benzo­yl)-5-ethyl­thio­phen-2-yl]aryl­amides, together with an isolated reaction inter­mediate: order versus disorder, mol­ecular conformations and hydrogen bonding in zero, one and two dimensions

Six N-[3-(2-chloro­benzo­yl)-5-ethyl­thio­phen-2-yl]aryl­amides have been synthesized and structurally characterized, revealing positional disorder in four of them, along with an isolated reaction inter­mediate. The mol­ecules of the amides are linked by different combinations of C—H⋯O and C—H⋯π(arene) hydrogen bonds, forming finite dimers, simple chains, chains of rings or sheets.

Characterization and gas adsorption of a novel three-dimensional metal–organic framework (MOF) generated from a new polydentate fluorene-bridged ligand

A polydentate ligand bridged by a fluorene group, namely 9,9-bis­(2-hy­droxy­eth­yl)-2,7-bis­(pyridin-4-yl)fluorene, has been prepared under solvothermal conditions and used to construct a three-dimensional metal–organic framework (MOF) with NiSO₄.

A new Cd^II coordination polymer with a self-penetrating architecture induced by the mol­ecular conformation of a rigid bi­thio­phene ligand

A self-penetrating architecture has been synthesized via mol­ecular conformation control operating on a rigid 2,2′-bi­thio­phene ligand under solvothermal conditions. The most inter­esting feature is the co-existence of trans and cis conformations in a single net, allowing the structural inter­penetration of self-threading and yet the expected self-penetrating structure was obtained.

Crystal and electronic structure of a hexa­carbonyl­diiron cluster tethered to naphthalene-2-thiol­ate ligands

The mol­ecular structure of [(μ-naphthalene-2-thiol­ato)₂Fe₂(CO)₆], determined by X-ray diffraction, displays inter­molecular π–π stacking inter­actions between the naphthalene rings, which was confirmed by Hirshfield surface analysis. The electronic spectrum shows a band which can be attributed to a π→π* electronic transition within the naphthalene moiety and a metal-based d→d transition.

High-temperature monoclinic α-SrHfF₆, and isostructural α-SrZrF₆: associating Hf₂F₁₂ bipolyhedra and SrF₈ snub disphenoids

The crystal structure of α-SrHfF₆ corresponds to a new structure type in the ABX₆ series. It associates Hf₂F₁₂ bipolyhedra and SrF₈ snub disphenoids, forming zigzag twisted [SrF₆]_n layers.

Promising solid electrolyte material for an IT-SOFC: crystal structure of the cerium gadolinium holmium oxide Ce_0.8Gd_0.1Ho_0.1O_1.9 between 295 and 1023 K

Rietveld refinements of the powder X-ray diffraction data of the electrolyte material Ce_0.8Gd_0.1Ho_0.1O_1.9 show that it is a fluorite with the space group Fmm and that it has crystal structure stability from room temperature to elevated temperatures.

Two novel alkaline earth coordination polymers constructed from cinnamic acid and 1,10-phenanthroline: synthesis and structural and thermal properties

Two new complexes of alkaline earth ions with the cinnamate ligand are presented. Hydrogen bonding plays an important role in the stablization of the three-dimensional supra­molecular frameworks. The thermal decompositions in the temperature range 297–1173 K revealed that each of the complexes decomposes in three steps and transforms to the corresponding metal oxide.