The first crystal structures of six- and seven-membered tellurium- and nitro­gen-containing (Te—N) heterocycles: 2H-1,4-benzo­tellurazin-3(4H)-one and 2,3-di­hydro-1,5-benzo­tellurazepin-4(5H)-one

The structures of a six- and a seven-membered tellurium- and nitro­gen-containing (Te—N) heterocycle represent the first structurally characterized members of their respective classes. When compared to their sulfur analogs, they exhibit slightly greater deviations from planarity to accommodate the larger chalcogenide atom. Inter­molecular N—H⋯O hydrogen bonding forms centrosymmetric (8) dimers in the six-membered hetereocyclic compound and chains in the seven-membered hetereocyclic compound, while inter­molecular Te⋯O contacts exist in the former.

Four supra­molecular isomers of di­chlorido­bis­(1,10-phenanthroline)cobalt(II): synthesis, structure characterization and isomerization

Changes in the heating rate and reaction temperature leads to the formation of four supra­molecular isomers of di­chlorido­bis­(1,10-phenanthroline)cobalt(II) from di­methyl­formamide. The structures and isomerization behaviours of the four isomers are discussed.

Structural corroboration of two important building blocks of the anti­cancer drug eribulin mesylate through two-dimensional NMR and single-crystal X-ray diffraction studies

Two building blocks having a major influence on the stereochemical orchestration of the drug mol­ecule eribulin mesylate were prepared and their two-dimensional nuclear magnetic resonance (2D-NMR) spectra generated. These data were corroborated by the single-crystal X-ray diffraction data generated for these mol­ecules.

Synthesis, crystal structure and magnetic properties of a two-dimensional cyanide-based heterometallic coordination polymer with cationic piperazinium ligands: poly[aqua­tetra-μ₂-cyanido-κ⁸C:N-dicyan­ido-κ²C-(piperazinium-κN⁴)cobalt(III)copper(II)]

A two-dimensional cyanide-bridged bimetallic coordination polymer [Cu^IICo^III(CN)₆(Hpip)(H₂O)]_n (Hpip is piperazinium) exhibits a two-dimensional (4,4) grid-like structure, in which cationic [Cu^II(Hpip)(H₂O)]³⁺ and anionic [Co^III(CN)₆]³⁻ units are linked through bridging cyanide ligands. The grid is further extended into a three-dimensional supra­molecular network through hydrogen-bonding inter­actions. A magnetic investigation shows anti­ferromagnetic coupling in the compound.

Hydrogen-bonding patterns in bis­[2,4,6-tri­azan­iumylcyclo­hexane-1,3,5-tris­(olate)-κ³O,O′,O′′]germanium(IV) tetra­chloride hexa­hydrate

In [Ge(taci)₂]₂Cl₈·12H₂O (taci is 1,3,5-tri­amino-1,3,5-tride­oxy-cis-inositol), the Ge^IV centre is exclusively bonded to the O-atom donors of two taci moieties. The taci ligand adopts a zwitterionic form with deprotonated hy­droxy groups and protonated amino groups. Extended hydrogen bonding constitutes a complex three-dimensional network.

3′:5′-Cyclic nucleotides: two sodium salts of cdTMP

Two salts of thymidine 3′:5′-cyclic phosphate (cdTMP), namely Na(cdTMP)·7H₂O, (I), with Z′ = 1, and Na(cdTMP)·3.7H₂O, (II), with Z′ = 8, are compared in terms of cyclic nucleotide conformation, inter-nucleotide interactions and nucleotide–sodium interactions.

The dangerous new synthetic drug α-PVP as the hydrated chloride salt α-pyrrolidinopentio­phenone hydro­chloride 0.786-hydrate

The dangerous new drug α-PVP crystallizes as the chloride salt with slightly less than a full solvent water mol­ecule, forming hydrogen bonds between each of the water H atoms and the chloride ion, which is itself hydrogen bonded to the quaternary N atom of the drug cation. A comparison with the structure of a number of other bath salts shows that, even though the bond between the phenyl group and the ketone group has free rotation, the conformation is essentially always the same.

Similar mol­ecular constitutions but different conformations and different supra­molecular assemblies in two related fused tetra­cyclic benzo[b]pyrimido[5,4-f]azepine derivatives

Two related fused tetra­cyclic benzo[b]pyrimido[5,4-f]azepine derivatives exhibit very different conformations for the azepine ring and very different patterns of supra­molecular assembly.

Triclinic and monoclinic polymorphs of meso-(E,E)-1,1′-[1,2-bis­(4-chloro­phen­yl)ethane-1,2-di­yl]bis­(phenyl­diazene): the high-yield synthesis of an unexpected product, concomitant polymorphism and configurational disorder

meso-(E,E)-1,1′-[1,2-Bis(4-chloro­phen­yl)ethane-1,2-di­yl]bis­(phenyl­diazene) was formed in high yield in the reaction between 4-chloro­benzaldehyde and 1-phenyl­pyrazolidine-3,5-dione, and crystallized from ethanol to give triclinic and monoclinic polymorphs, where the monoclinic polymorph exhibits configurational disorder. The only significant inter­molecular contacts are of the C—Cl⋯π(arene) type in the triclinic polymorph and of the C—H⋯N and C—H⋯π(arene) types in the monoclinic polymorph.

An unusual coordination polymer containing Cu⁺ ions and featuring possible Cu⋯Cu `cuprophilic' inter­actions: poly[di-μ-chlorido-(μ₄-3,5-di­amino­benzoato-κ⁴O:O′:N:N′)tricopper(I)(3 Cu—Cu)]

A three-dimensional Cu⁺-containing coordination polymer, formed from the in situ reduction of CuCl₂ in the presence of 3,5-di­amino­benzoic acid and KOH, contains ten distinct Cu^I atoms, two of which lie on crystallographic inversion centres. Each Cu^I atom is associated with two adjacent metal atoms and if all these are regarded as `cuprophilic' inter­actions, then infinite [01] zigzag chains of Cu^I atoms occur in the crystal.

A coordinatively flexible hexa­dentate ligand gives structurally isomeric complexes M₂(L)X₃ (M = Cu, Zn; X = Br, Cl)

Cu₂(tpena)Br₃ and Zn₂(tpena)X₃ [X = Br or Cl and tpena = N,N,N′-tris­(pyridin-2-ylmeth­yl)ethyl­enedi­amine-N′-acetate] show distinctly different mol­ecular structures despite being indistinguishable using routine spectroscopic techniques. The ligand is unexpectedly dinucleating in the case of the copper complex, while it bridges to a [ZnX₃]⁻ unit in the zinc complexes.

Planarity of benzoyl­dithio­carbazate tuberculostatics. II. Diesters of benzoyldi­thiocarbazic acid

The structure analyses of three benzoyl­hydrazine–di­thio­carbazoate derivatives support the hypothesis that planarity of their mol­ecules plays an important role in their tuberculostatic activity.

V₂O₂F₄(H₂O)₂·H₂O: a new V⁴⁺ layer structure related to VOF₃

A new V⁴⁺ layer structure, V₂O₂F₄(H₂O)₂·H₂O, built up of VOF₄(H₂O) corner- and edge-sharing octa­hedral building units, with structural relationships to previously synthesized vanadium oxyfluoride compounds, has been synthesized via solvothermal methods.

6-Chloro­isocytosine and 5-bromo-6-methyl­isocytosine: again, one or two tautomers present in the same crystal?

6-Chloro­isocytosine has been cocrystallized with two coformers in an approach intended to obtain the donor–donor–acceptor/acceptor–acceptor–donor synthon, as well as to determine the tautomerism.