Isolation and crystal and mol­ecular structures of [(C₅H₂Br₃)₂Fe], [(C₅HBr₄)₂Fe] and [(C₅Br₅)(C₅Br₄HgBr)Fe]

Hexa- and octa­bromo­ferrocene, as well as a mercury derivative of deca­bromo­ferrocene, were isolated from mixtures of polybromo­ferrocenes and characterized by X-ray diffraction. The crystals show halogen and hydrogen bonding, which act co-operatively.

Carbon-atom hybridization tunes the halogen-bond strength in the series of DABCO·C₂H_2nI₂ (n = 0–2) cocrystals

The series of cocrystals of 1,4-di­aza­bicyclo­[2.2.2]octane (DABCO) with 1,2-di­iodo­acetyl­ene (C₂I₂), 1,2-di­iodo­ethene (1,2-C₂H₂I₂) and 1,2-di­iodo­ethane (1,2-C₂H₄I₂) illustrate the correlation between the strength of the α-C—I⋯N halogen bond and polarization of the I atom as a function of the α-C-atom hybridization.

Qu­anti­tative insights into noncovalent inter­actions involving halogen and tetrel bonds in 2,4,6-tri­methyl­pyrylium tetra­fluoro­borate

The crystal structure of 2,4,6-tri­methyl­pyrylium tetra­fluoro­borate reveals a significant contribution of fluorine-centred inter­actions, com­prising F⋯O, F⋯π and C—H⋯F contacts, which governs the crystal packing in the solid state. The qu­anti­tative and qualitative aspects of these contacts were also established.

Single-crystal structure refinements and Debye temperatures of Ir₂S₃ kashinite and Rh₂S₃ bowieite

The structures of synthesized Ir₂S₃ and Rh₂S₃ were refined using single-crystal X-ray diffraction. Crystallization of these minerals in the Earth's mantle was discussed with respect to the obtained Debye temperature.

Cd^II-based com­pound as a multi-responsive fluorescent probe for sensing Fe^III cations and Cr^VI oxyanions

A novel Cd^II com­pound with a two-dimensional structure was obtained by self-assembly from 5-[(3-carb­oxy­phen­oxy)meth­yl]isophthalic acid. The structure was analyzed and the photoluminescence properties were explored. The com­pound shows a high selectivity and sensitivity for detecting Fe^III cations and Cr^VI oxyanions in aqueous solution, with a low detection limit of 0.19 µM for Fe³⁺ ions and 1.13 µM for Cr₂O₇²⁻ ions.

On the use of Hirsh­feld surfaces for estimating atomic charges in ionic species: crystal structure of the natural ilmenite (Mg_0.4168Fe_0.5832)TiO₃

This work focuses on the structure solution and refinement of a natural ilmenite single crystal and on the application of a new methodology based on the Hirsh­feld stockholder concept to estimate the charges and radius in the ionic crystals.

3,4-Bis-O-propargyl-1,2:5,6-di-O-iso­propyl­idene-D-mannitol: a study of multiple weak hydrogen bonds in the solid state

Primary weak hydrogen bonds in each of three independent mol­ecules in 3,4-bis-O-propargyl-1,2:5,6-di-O-iso­propyl­idene-D-mannitol are elucidated by single-crystal X-ray diffraction and their importance in mol­ecular con­formation and crystal packing determined. Parallel searches of the Cambridge Structural Database using motifs based on donor and acceptor propargyl D—H⋯A contacts reveal distance and angle dependencies that are especially sensitive to acceptor type, so, together, these findings will be beneficial in applications for the mol­ecule and its congeners as anion binders and precursors for the synthesis of macrocycles.

Crystal and mesophase structure of a bi­cyclo­hexyl cyano mesogen

4-[trans-4-(trans-4-Propyl­cyclo­hex­yl)cyclo­hex­yl]benzo­nitrile has two different solid phases and exhibits thermotropic liquid-crystalline behaviour, with a remarkable inter­val of stability of the mesophase between the lower melting solid phase (75 °C) and the isotropization tem­per­ature (247 °C).

Complexes of 2,4,6-tri­hydroxy­benzoic acid: effects of intra­molecular hydrogen bonding on ligand geometry and metal binding modes

More than 20 new compounds derived from 2,4,6-tri­hydroxy­benzoic acid (H₄thba) have been synthesized, with structures that include discrete mol­ecular units and chains, in addition to two- and three-dimensional nets. Intra­molecular hydro­gen bonds between the ortho-hy­droxy groups and the car­box­yl­ate group in the H₃thba⁻ anion confer a rigid geometry upon the ligand which, when combined with the low basicity of the car­box­yl­ate group, limits the variety of metal-binding modes.

Synthesis, and spectroscopic and structural characterization of three new styryl­quinoline–benzimidazole hybrids

Three new 4-styryl­quinoline–benzimidazole hybrids have been synthesized in a two-step reaction sequence. The styryl­quinoline fragments are all nonplanar and the mol­ecules are linked into two- or three-dimensional arrays by N—H⋯O and C—H⋯π hydrogen bonds.

Synthesis, crystal structure and Hirshfeld analysis of tri­phenyl­phosphine–(4-bromo­phen­yl)borane

Synthesis, spectroscopic characterization and Hirshfeld analysis of a new tri­phenyl­phosphine–organoborane adduct reveal the presence of di­hydrogen bonding, C—H⋯π inter­actions and Br⋯Br inter­actions in the solid state.

A new heteroleptic cuprous polymer constructed by a cyano­pyridine ligand exhibiting a supra­molecular framework structure and luminescence

In the title heteroleptic cuprous polymer solvate, (9,9-dimethyl-9H-xanthene-4,5-di­yl)bis­(di­phenyl­phosphane) and pyridine-3-carbo­nitrile exhibit chelating and bridging coordination modes, respectively. The cuprous polymer cations show a racemic helical chain structure and form a stable supra­molecular metal–organic framework structure through C—H⋯π inter­actions among helical chains.