Caesium bis­(5-bromo­salicyl­aldehyde thio­semicarbazonato-κ³O,N,S)ferrate(III): supramolecular arrangement of low-spin Fe^III complex anions mediated by Cs⁺ cations

In the crystal structure of the Fe^III coordination compound with 5-bromo­salicyl­aldehyde thio­semicarbazonate, the distorted octa­hedral Fe^III S₂N₂O₂ chromophore contains two O,N,S-donating dianionic 5-bromo­salicyl­aldehyde thio­semicarbazonate(2−) ligands in perpendicular planes, with the O and S atoms in cis positions and the N atoms in trans positions. The Fe^III cation is in the low-spin state at 293 K.

Exo conformers of N-(pyridin-2-yl)- and N-(pyridin-3-yl)norbornene-5,6-dicarboximide crystals

In two exo-isomeric pyridine-substituted norbornenedicarboximide derivatives, the asymmetric units consist of two independent mol­ecules (Z′ = 2). In one isomer, the pyridine rings of the two independent mol­ecules adopt different conformations, i.e. syn and anti, with respect to the methyl­ene bridge. In contrast, in the second isomer, the pyridine rings of both mol­ecules have an anti conformation.

Synthesis and crystal structure of a novel prochiral keto­imine: (E)-aceto­phenone O-di­phenyl­phosphoryl oxime

In a novel activated prochiral keto­imine, (E)-aceto­phenone O-di­phenyl­phosphoryl oxime, the molecules pack together in the solid state via weak intermolecular C—H⋯O interactions and both face-to-face and edge-to-face π-stacking interactions.

[Mn₁₂O₁₂(O₂CMe)₁₂(NO₃)₄(H₂O)₄]: facile synthesis of a new type of Mn₁₂ complex

The first example of a novel Mn₁₂ core containing nitrate ligands and which was made directly in situ is presented. Similar versions of this core have been synthesized previously, however, the present method is superior in its simplicity and high yield of the title compound.

Tris(tri-o-tolyl phosphite-κP)nickel: a coordinatively unsaturated nickel(0) complex

The zero-valent nickel complex, Ni[P(O-o-tolyl₃)₃], has been crystallized in the space group C2/c. Some close agostic interactions are observed between aryl H atoms and the Ni⁰ centre.

Towards validating new enzymatic routes for synthetic conversion: 7,10-bis-O-(2,2,2-tri­chloro­eth­oxy­carbon­yl)-10-de­acetyl baccatin III–ethyl acetate–water (1/1/1)

7,10-Bis-O-(2,2,2-tri­chloro­eth­oxy­carbon­yl)-10-deacetyl baccatin III (7,10-di-Troc-DAB)–water—ethyl acetate (1/1/1), prepared by the reaction of 10-deacetyl baccatin III with 2,2,2-tri­chloro­ethyl chloro­formate in pyridine, crystallizes via strong inter­molecular hydrogen bonds. In the crystal, mol­ecules are linked via multiple hydrogen bonds and noncovalent inter­actions. A detailed comparison of the molecular conformation with those of related structures is presented.

Incorporating two different chromophores onto a silicon atom: the crystal structure and photophysical properties of 9-{4-[(9,9-di­methyl-9H-fluoren-2-yl)di­methylsilyl]phenyl}-9H-carbazole

The crystal structure of a bifunctional silicon-bridged compound is reported, together with its photophysical properties and theoretical investigations.

Captopril and its dimer captopril di­sulfide: comparative structural and conformational studies

The mol­ecular geometries of captopril and its dimer captopril di­sulfide are quite similar, but certain differences appear in the conformations of the five-membered proline rings and the side chains containing the sulfhydryl group. A minimum-energy conformational search using Monte Carlo methods in the aqueous phase reveals that the optimized conformations of these compounds differ from those determined crystallographically, which depend on their immediate environment.

Two polymorphs of 5-cyclo­hexyl-5-ethyl­barbituric acid and their packing relationships with other barbiturates

Two forms of 5-cyclo­hexyl-5-ethyl­barbituric acid, containing either hydrogen-bonded chains or layers, are structurally closely related to analogous barbiturates.

The peptide NCbz-Val-Tyr-OMe and aromatic π–π interactions

Several inter- and intramolecular aromatic π–π interactions stabilize the packing in the crystal structure of a protected dipeptide which adopts an extended conformation. The geometry of these aromatic π–π interactions is analysed and presented.

A list of organo­metallic krypto­racemates

The vast majority of racemic solutions of chiral compounds apparently crystallize at room temperature in non-Sohncke space groups as racemic crystals. However, krypto­racemic crystals composed of nearly enantio­meric pairs occasionally crystallize at room temperature, or appear as low-temperature phases, in Sohncke space groups. 1412 chiral organo­metallic crystal structures have been extracted from the Cambridge Structural Database and analyzed.

Syntheses and crystal structures of two magnesium–tetra­zole compounds in salt and polymeric forms

The crystal structures of two magnesium(II) compounds with tetra­zole ligands reveal two different forms, one one-dimensional polymeric with a dimeric unit and the second as a salt with tetra­zole in the mono-ionized state. The framework of the first form is dominated by a significant number of hydrogen bonds involving all water mol­ecules, while the topology of the second form may be described as a 4,8c flu net.

Cocrystals of 6-methyl-2-thio­uracil: presence of the acceptor–donor–acceptor/donor–acceptor–donor synthon

Seven cocrystal structures of 6-methyl-2-thio­uracil with coformers containing the 2,4-di­amino­pyrimidine substructure are presented. In six of the structures, the acceptor–donor–acceptor/donor–acceptor–donor N—H⋯O/N—H⋯N/N—H⋯S synthon is observed and in only one structure is an acceptor–donor/donor–acceptor inter­action formed instead.

Structure determination and modeling of monoclinic trioctylphosphine oxide

Trioctylphosphine oxide (TOPO) was recrystallized from ambient evaporation in acetone. Fourier transform IR (FT–IR) spectroscopy captures the characteristic stretching modes from the seven methyl­ene groups, the phosphoryl P=O bond, and the phosphor­yl–carbon bond.