The hydro­chloride and hydro­bromide salt forms of (S)-amphetamine

Relatively few structural studies of the salt forms of amphetamine have been reported. The structures of (S)-amphetamine hydro­chloride and hydro­bromide are broadly similar in terms of cation conformation, the existence of three N—H⋯X hydrogen-bond contacts per anion and the overall two-dimensional hydrogen-bonded sheet motif. However, only the hydro­chloride structure features organic bilayers and Z′ > 1.

Two different anionic manganese(II) coordination polymers constructed through dicyanamide coordination bridges

In order to explore new metal coordination polymers and to search for new types of ferroelectrics among hybrid coordination polymers, the use of tetra­methyl­ammonium and butyl­tri­phenyl­phospho­nium cations as templates for the formation of two different manganese(II) coordination polymers with dicyanamide was investigated.

A moderate distortion of the `picket-fence' porphyrin (cryptand-222)potassium chlorido[meso-α,α,α,α-tetra­kis­(o-pivalamido­phenyl)porphyrinato]ferrate(II) n-hexane monosolvate

A moderate distortion of the `picket-fence' porphyrin, (cryptand-222)potassium chlorido[meso-α,α,α,α-tetrakis(o-pivalamidophenyl)porphyrinato]ferrate(II), [K(222)][Fe(TpivPP)Cl], was observed, with the porphyrin core showing significant doming and the Fe atom displaced by 0.62 Å from the porphyrin plane.

Structure and packing of aminoxyl and piperidinyl acryl­amide monomers

The mol­ecular and crystal structures of 2,2,6,6-tetra­methyl-4-acryl­amido-1-piperidine-1-oxyl and N-(2,2,6,6-tetra­methyl­piperidin-4-yl)acryl­amide, synthesised as precursors to redox-active polymer gel systems, are reported.

Unusual centrosymmetric structure of [M(18-crown-6)]⁺ (M = Rb, Cs and NH₄) complexes stabilized in an environment of hexa­chlorido­antimonate(V) anions

In a series of isomorphous compounds, [M(18-crown-6)]⁺ cations (M = Rb, Cs and NH₄) and [SbCl₆]⁻ anions afford linear stacks, which stablize an unusual centrosymmetric structure of the macrocyclic groups, with the large cations (caesium, rubidium or ammonium) approaching the centre of the 18-crown-6 cavity.

Polymorphism in 3-acetyl-4-hy­droxy-2H-chromen-2-one

Two polymorphs of 3 acetyl-4-hydroxy­coumarin differ mainly in the packing of the mol­ecules, with π–π stacking inter­actions between keto–enol hydrogen-bonded rings stabilizing the first form and the second form being stabilized by inter­actions between α-pyrone rings.

Two new cadmium(II) coordination polymers based on bis­(1,2,4-triazol-1-yl)alkane ligands and pyrazine-2,3-di­carb­oxy­lic acid

Comparing the structures of the two complexes formed from pyrazine-2,3-di­carb­oxy­lic acid and Cd^II in the presence of bis­(1,2,4-triazol-1-yl)butane or bis­(1,2,4-triazol-1-yl)ethane, it seems that the length of the flexible bis­(1,2,4-triazol-1-yl)alkane ligand and the coordination modes of the pyrazine-2,3-di­carboxyl­ate anionic ligand might play key roles in determining the structures.

A structural study of Si₆-ring-containing [Si₆Cl₁₄]²⁻ chloro­silicates

In the crystal structures of four substituted-ammonium dichloride dodeca­chloro­hexa­silanes, the dodeca­chloro­hexa­silane ring is located on a crystallographic centre of inversion. The geometry of the dichloride dodeca­chloro­hexa­silanes in the different structures is almost the same, irrespective of the cocrystallized cation and solvent.

A new Co^II complex of diniconazole: synthesis, crystal structure and anti­fungal activity

A new Co^II complex incorporating diniconazole as a ligand adopts an octa­hedral geometry, coordinated by two water O atoms and by four diniconazole N atoms. The anti­fungal activity of this complex is enhanced for Botryosphaeria ribis and Botryosphaeria berengriana, but reduced for Gibberella nicotiancola and Alternariasolani compared to that of diniconazole.

Synthesis and structure determination of seven ternary bis­muthides: crystal chemistry of the RELi₃Bi₂ family (RE = La–Nd, Sm, Gd, and Tb)

RELi₃Bi₂ (RE = La–Nd, Sm, Gd, Tb) phases are challenging to synthesize and characterize, and many of the seven reported structures are the first known compounds in the respective RE–Li–Bi ternary phase diagrams.

Halogen-bonded adduct of 1,2-di­bromo-1,1,2,2-tetra­fluoro­ethane and 1,4-di­aza­bicyclo­[2.2.2]octa­ne

The adduct formed between 1,4-di­aza­bicyclo­[2.2.2]octa­ne and BrCF₂CF₂Br exhibits a one-dimensional polymeric structure in which the C—N⋯Br halogen-bond length is shorter than the average for related type I C—N⋯Br—C halogen-bonded systems, and shorter than found in two other reported crystal structures of related BrCF₂CF₂Br adducts.

The first three-dimensional Fe^III–Sr^II heterometallic coordination polymer: poly[[di­aqua­tetra­kis­(μ₃-pyridine-2,3-di­carboxyl­ato)diiron(III)strontium(II)] dihydrate]

The first three-dimensional Fe^III–Sr^II heterometallic coordination polymer was prepared by the reaction of pyridine-2,3-di­carb­oxy­lic acid (H₂pydc), SrCl₂·6H₂O and Fe(OAc)₂(OH) (OAc is acetate). One-dimensional [Fe₂(pydc)₄]_n chains are connected by Sr^II cations to form a three-dimensional framework. The topology type of this framework is tfj.

Photoluminescence properties of a cationic tri­nuclear zinc(II) complex with the tetradentate Schiff base ligand 6-methyl-2-({[(pyridin-2-yl)meth­yl]imino}­meth­yl)phenolate

Metal complexes with Schiff base ligands have been suggested as potential phosphors in electroluminescent devices. A trinuclear zinc(II) cluster with tetradentate 6-methyl-2-({[(pyridin-2-yl)meth­yl]imino}­meth­yl)phenolate ligands exhibits a strong emission at 469 nm with a quantum yield of 15.5%.

5-Iodo­uracil: structure of a reflection twin

The crystal structure of 5-iodo­uracil has been determined in the noncentrosymmetric space group P2₁ on a nonmerohedrally twinned crystal. Both twin components are enanti­omorphically pure, but the twin element is a mirror plane perpendicular to c*.

Methods of space-group determination – a supplement dealing with twinned crystals and metric specialization

Tables, in the form of a spreadsheet for use on a computer, enable the determination of space group for single crystals, twinned crystals and crystals with a specialized metric.

Crystal structures of four δ-keto esters and a Cambridge Structural Database analysis of cyano–halogen interactions

The crystal structures of three related δ-keto esters have been analysed and compared with a previously known structure. Two of the structures have cyano–halogen interactions. A Cambridge Structural Database analysis of the geometric aspects of cyano–halogen interactions idindicates that all the short cyano–halogen contacts in the CSD can be classified as halogen bonds, which are directional noncovalent interactions.

One-dimensional Cu^II coordination polymers containing C_2h-symmetric 1,1′:4′,1′′-terphenyl-3,3′-di­carboxyl­ate linkers

Two new one-dimensional Cu^II coordination polymers containing a C_2h-symmetric 1,1′:4′,1′′-terphenyl-3,3′-di­carboxyl­ate linker were both obtained from different preparation methods: one reaction was performed in the presence of 1,4-di­aza­bicyclo­[2.2.2]octane (DABCO) as a potential pillar ligand and the other was carried out in the absence of the DABCO pillar.