Absolute structure determination using CRYSTALS

Report and recommendations from an investigation of absolute structure analysis using tools available in the software CRYSTALS.

Cis–trans isomerism in a square-planar platinum(II) complex bearing bulky fluorinated phosphane ligands

Two geometric isomers of a [Pt(thiol­ato-κS)₂(phosphane-κP)₂] complex have been characterized, with the aim of explaining why the cis–trans equilibrium established in solution is not totally displaced towards the trans isomer.

Carboxyl­ate–phenolate tautomerism in 5-[(nitro­phen­yl)diazen­yl]salicylate anions

In the crystals of their tetra­methyl­ammonium salts, the 5-[(2-nitro­phen­yl)diazen­yl]salicylate anion is an almost pure phenol–carboxyl­ate tautomer, whereas the 4-nitro isomer is inter­mediate between the phenol–carboxyl­ate and phenolate–carb­oxy­lic acid tautomeric forms. The possible formation of such an inter­mediate form is supported by quantum chemical calculations.

Sulfonate salts of the therapeutic agent dapsone: 4-[(4-amino­phen­yl)sulfon­yl]anilinium benzene­sulfonate monohydrate and 4-[(4-amino­phen­yl)sulfon­yl]anilinium methane­sulfonate monohydrate

The benzene­sulfonate and methane­sulfonate salts of the therapeutic agent dapsone each form a hydrogen-bonded network incorporating water in the lattice. The benzene­sulfonate salt forms a two-dimensional network, while the hydrogen bonding within the methane­sulfonate salt results in a three-dimensional network.

Synthesis and characterization of two novel bimetallic macrocyclic complexes generated from 1,2,4-triazole-containing semi-rigid ligands and M(NO₃)₂ units (M = Ni and Zn)

The semi-rigid organic ligand 3-[(pyridin-4-yl­methyl)sulfanyl]-5-(quinolin-2-yl)-4H-1,2,4-triazol-4-amine has been used to form two novel bimetallic macrocycle complexes with nickel(II) and zinc(II). In the former, the macrocycles are extended into a two-dimensional network via N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds. In the latter, one type of bimetallic ring constructs a one-dimensional nanotube via O—H⋯O and N—H⋯O hydrogen bonds, and the other constructs zero-dimensional mol­ecular cages via O—H⋯O and N—H⋯O hydrogen bonds.

Comparison of the crystal structures of the potent anti­cancer and anti-angiogenic agent regorafenib and its monohydrate

Regorafenib is a potent anti­cancer and anti-angiogenic agent and has been crystallized as polymorphic form I and as the monohydrate. A comparison of both forms shows that they differ in the relative orientation of the bi­aryl­urea and pyridine-2-carboxamide units. Conformational differences are reflected in different hydrogen-bond networks.

Redetermination of the crystal structure of boron subphthalocyanine chloride (Cl-BsubPc) enabled by slow train sublimation

The crystal structure of boron subphthalocyanine chloride (Cl-BsubPc) has been redetermined with a higher precision 41 years after its original publication, using large single crystals grown via slow train sublimation and diffracted at several temperatures. Inter­molecular π–π and halogen–π (B—Cl⋯π) inter­actions are discussed with reference to the Hirshfeld surface.

A two-dimensional zinc(II) coordination polymer based on mixed di­methyl succinate and bi­pyridine ligands: synthesis, structure, thermostability and luminescence properties

A two-dimensional zinc(II) coordination polymer, based on 2,2-di­methyl­succinate and 4,4′-bi­pyridine coligands, was prepared under hydro­thermal conditions and structurally characterized. The complex was also characterized by elemental, IR and thermogravimetric analyses. The luminescence properties were investigated and the compound exhibits a blue photoluminescence in the solid state at room temperature.

π–π stacking motifs in di­alkyl­bis­{5-[(E)-2-aryl­diazen-1-yl]-2-hy­droxy­benzoato}tin(IV) complexes

The diorganotin(IV) complexes of 5-[(E)-2-aryl­diazen-1-yl]-2-hy­droxy­benzoic acid are of inter­est because of their structural diversity in the crystalline state and their inter­esting biological activity. The diversity of π–π stacking motifs in six structures of this series is examined in detail.

Crystal structure and bonding analysis of the first dinuclear calcium(II)–proton-pump inhibitor (PPI) `butterfly mol­ecule': a combined microcrystal synchrotron and DFT study

The crystal structure analysis of a novel calcium–PPI compound incorporating bridging and terminal (R)-rabeprazole tricyclic ligands, using low-temperature microcrystal synchrotron radiation, shows it to have the form of a beautiful 'butterfly mol­ecule'. The nonbonded Ca⋯Ca distance is significantly longer than in other calcium dimers, indicating steric hindrance in the bidentate bridging ligands.

Supra­molecular hydrogen-bonding patterns in the organic–inorganic hybrid compound bis­(4-amino-5-chloro-2,6-di­methyl­pyrimidinium) tetra­thio­cyanato­zinc(II)–4-amino-5-chloro-2,6-di­methyl­pyrimidine–water (1/2/2)

In the organic–inorganic hybrid compound prepared by the combination of an amino­pyrimidine base and a zinc thio­cyanate anion, the cationic and anionic species are linked predominantly through hydrogen bonds and π–π stacking inter­actions to form a three-dimensional hydrogen-bonded network. The pyrimidine mol­ecules and pyrimidinium cations also form base-pair-like structures via N—H⋯N hydrogen bonds with an (8) ring motif.

Nontypical iodine–halogen bonds in the crystal structure of (3E)-8-chloro-3-iodo­methyl­idene-2,3-di­hydro-1,4-oxazino[2,3,4-ij]quinolin-4-ium triiodide

A new di­hydro­oxazinoquinolinium triiodide has been synthesized and characterized by single-crystal X-ray diffraction analysis, Raman spectroscopy and thermal analysis. The iodine–iodine halogen bonds formed between neighbouring triiodide anions and between triiodide anions and iodine-containing heterocyclic cations are the basis of the noncovalent inter­actions in the analyzed crystal.

Six polycyclic pyrimidoazepine derivatives: syntheses, mol­ecular structures and supra­molecular assembly

Substituted polycyclic pyrimidoazepine derivatives can be prepared by nucleophilic substitution reactions on the corresponding chloro compounds using either conventional heating in solution or microwave heating in the absence of solvent. No two of the six structures reported here contain the same range of inter­molecular hydrogen bonds or show the same type of supramolecular assembly.

A three-dimensional mixed-valence Cu^II/Cu^I coordination polymer constructed from bi­phenyl-3,4′,5-tri­carboxyl­ate and 1,4-bis­(1H-imidazol-1-yl)benzene ligands

A novel three-dimensional Cu^II/Cu^I coordination polymer, with a (2,2,3,4,4)-connected topological network, was assembled from biphenyl-3,4′,5-tri­carb­oxy­lic acid and 1,4-bis­(1H-imidazol-1-yl)benzene. An investigation of the magnetic properties indicated a very weak ferromagnetic behaviour.