A structural com­parison of salt forms of dopamine with the structures of other phenyl­ethyl­amines

In four new dopamine salts, the dopamine cation adopts an extended conformation. Inter­molecular inter­action motifs that are common in the salt forms of tyramine can be found in related dopamine structures, but hydrogen bonding in the dopamine structures appear to be more variable and less predictable than for tyramine.

X-ray-determined structure of the technetium com­plex [Tc₂(μ-CO)₂(NC₅H₅)₂(CO)₆] revisited: [Tc₂(μ-OMe)₂(NC₅H₅)₂(CO)₆] as the correct formulation

New processing of the raw diffraction data of a com­pound formulated in 2008 as [Tc₂(μ-CO)₂(NC₅H₅)₂(CO)₆] has revealed that the bridging ligands were actually methoxide. The formation of [Tc₂(μ-OMe)₂(NC₅H₅)₂(CO)₆] in the room-temperature reaction of [Tc₂(CO)₁₀] with pyridine might have been facilitated at the time by the presence of trace amounts of methanol and air in the reaction mixture.

From liquid to crystal via mechanochemical grinding: unique host–guest (HOF) co­crystal

Mechanochemical synthesis via grinding of trimesic acid and 4-chloro­phenyl diphenyl phosphate (liquid at room temperature) in a 1:1 ratio resulted in the formation of an inclusion type of co­crystal. The crystallization of this phase via slow evaporation at low temperature (276–277 K) from methanol resulted in a rare `stairstep morphology' during the process of crystal growth.

Two new bis­muth salts with succinic acid: synthesis, structural, spectroscopic and thermal characterization

The synthesis, structural determination, spectroscopic and thermal characterization of two bis­muth succinate hydrates are presented. Both com­pounds are coordination polymers.

Pressure-induced metallization in the absence of a structural transition in the layered transition-metal dichalcogenide ZrSe₂

First-principles calculations were carried out on ZrSe₂, which has been of interest owing to its technologically important physical properties. The structural, electronic and optical properties of this compound were investigated under pressure through the plane wave pseudopotential approach within the framework of density functional theory. The optical properties of hexagonal ZrSe₂ undergo a red shift with increasing pressure.

Synthesis, structures and properties of two donor–acceptor acridone-based com­pounds

Two acridone-based com­pounds, synthesized by a two-step route, adopt different mol­ecular orientations and packing styles, and the torsional vibration of the di­cyano­methyl­enated acridone (DCNAD) skeleton is suppressed by C≡N⋯π inter­actions, which makes the crystals exhibit fluorescence.

Supra­molecular inter­actions in some organic hydrated 2,4,6-tri­amino­pyrimi­din­ium carboxyl­ate and sulfate salts

The hydro­gen-bond inter­actions exhibited by four pyrimidinium salts generate a variety of supra­molecular assemblies in three-dimensional space as networks, sheets and ladders. The mol­ecular recognition process, recurring hydro­gen-bond motifs and supra­molecular assemblies will help in fine tuning properties for desired needs.