LaTe_1.82(1): modulated crystal structure and chemical bonding of a chalcogen-deficient rare earth metal polytelluride

Small finite telluride anions are found as dominant species in the anionic layers of modulated LaTe_1.82(1), corresponding to its semiconducting properties.

A new monoclinic structure type for ternary gallide MgCoGa₂

The crystal structure of the new monoclinic ternary gallide MgCoGa₂ has been determined by the single-crystal method. The MgCoGa₂ structure type represents the structure family based on YPd₂Si and Fe₃C.

Two Zn^II-based MOFs constructed with bi­phenyl-2,2′,5,5′-tetra­carb­oxy­lic acid and flexible N-donor ligands: syntheses, structures and properties

Two Zn^II-based coordination polymers were prepared by solvothermal synthesis using biphenyl-2,2′,5,5′-tetra­carb­oxy­lic acid and ZnCl₂·4H₂O under the control of flexible N-donor ligands. In the structures, the Zn^II ions adopt distorted tetra­hedral geometries and are bound by tetra­carboxyl­ate ligands to produce a two-dimensional layer in one com­plex and a three-dimensional network in the other. Furthermore, the luminescence properties of the com­plexes were investigated and the ferroelectric properties of one of the com­plexes were shown to be a result of its polar point group C_2v.

Crystal structure and photoreactivity of a halogen-bonded cocrystal based upon 1,2-di­iodo­perchloro­benzene and 1,2-bis­(pyridin-4-yl)ethyl­ene

The role of I⋯N halogen bonding as a driving force to organize the organic solid state to achieve a [2 + 2] cyclo­addition reaction is presented. Within the cocrystal, the halogen-bond donor 1,2-di­iodo­perchloro­benzene is found to π–π stack in a homogeneous and face-to-face pattern, thereby positioning the reactant mol­ecule, trans-1,2-bis­(pyridin-4-yl)ethyl­ene, in the correct orientation to undergo a solid-state photoreaction.

Halobismuth(III) salts with substituted amino­pyridinium cations

The crystal structures of six halobismuth(III) salts of variously substituted amino­pyridinium cations are reported. Discrete mononuclear [BiCl₆]³⁻ and dinuclear [Bi₂X₁₀]⁴⁻ anions (X = Cl or Br), and polymeric cis-double-halo-bridged [Bi_nX_4n]ⁿ⁻ anionic chains (X = Br or I) were observed. The supra­molecular networks formed by classic N—H⋯X hydrogen bonds include ladders, bilayers and three-dimensional frameworks.

Synthesis, structural elucidation, characterization and theoretical DFT study of 1-(o-tol­yl)biguanidium chloride

In the salt 1-(o-tol­yl)biguanidium chloride, a correlation between electrostatic energy and contact enrichment is found only for the strongly attractive (N—H⋯Cl⁻) and repulsive contacts. Electrostatic energies between moieties reveal that inter­acting biguanidium cation pairs are repulsive and that the crystal is maintained by attractive cation⋯Cl⁻ dimers.

Chimeric supra­molecular synthons in Ph₂Te₂(I₂)Se

Iodination of Ph₂Te₂Se by mol­ecular iodine is directed towards the Te atom and yields PhTeSeTeI₂Ph. The mol­ecule can be considered as a chimera of PhTeSeR, PhTeSeTePh and R′TeI₂Ph fragments. The energies of the inter­molecular inter­actions have been calculated and analyzed.

Electronic stabilization by occupational disorder in the ternary bis­muthide Li_3–x–yIn_xBi (x ≃ 0.14, y ≃ 0.29)

The ternary bis­muthide Li_3–x–yIn_xBi (x ≃ 0.14, y ≃ 0.29) crystallizes in a 2 × 2 × 2 superstructure of the anti-BiF₃ type. A delicate inter­play between Li/In substitutional disorder and Li deficiency determines the electronic stability of the structure.

Can we trust the experiment? Anisotropic dis­placement parameters in 1-(halometh­yl)-3-nitro­benzene (halogen = Cl or Br)

Anisotropic displacement parameters for the isomorphous compounds 1-(halometh­yl)-3-nitro­benzene (halo = chloro and bromo) were calculated from first principles and determined by X-ray diffraction experiments. Unexpectedly, the experiment for the bromo compound proved more challenging than theory.

Bulk polarity of 3,5,7-tri­nitro-1-aza­adam­antane mediated by asymmetric NO₂(lone pair)⋯NO₂(π-hole) supra­molecular bonding

Asymmetric NO₂⋯NO₂ inter­actions are responsible for the assembly of trigonal nets in the structure of 3,5,7-tri­nitro-1-aza­adam­an­tane and are significant for the breaking of inversion symmetry and the generation of supra­molecular polarity.

Syntheses and structures of two novel fluorescent metal–organic frameworks generated from a tridentate donor–acceptor motif ligand

The tridentate ligand 4,4′,4′′-(4,4,8,8,12,12-hexa­methyl-8,12-di­hydro-4H-benzo[9,1]quin­oli­zino[3,4,5,6,7-defg]acridine-2,6,10-tri­yl)tri­ben­zoic acid was characterized together with two coordination polymers with Cd and Zn cores. The photophysical properties of the three com­pounds were examined by direct measurements and com­putational models.

Self-assembly of a cobalt(II)-based metal–organic framework as an effective water-splitting heterogeneous catalyst for light-driven hydrogen production

The redox-active Co^II atoms of a metal–organic framework (MOF) constructed from 4,4′,4′′,4′′′-(ethene-1,1,2,2-tetra­yl)tetra­benzoic acid and 4,4′-bipyridyl as four-point- and two-point-connected nodes, respectively, could be used as the catalytic sites for hydrogen production via water splitting.

Ammonium bis­(salicyl­aldehyde thio­semi­car­bazonato)ferrate(III), a supra­molecular material containing low-spin Fe^III

The Fe^IIIS₂N₂O₂ chromophore of ammonium bis­[salicyl­aldehyde thio­semi­car­ba­zon­ato(2−)]iron(III) contains two O,N,S-donating salicyl­aldehyde thio­semi­car­ba­zon­ate(2−) ligands in perpendicular planes, with the O and S atoms in cis and the N atoms in trans positions. The Fe^III ion is in the low-spin state at 100 K. Systematic twinning by metric pseudomerohedry is explained by application of the order–disorder (OD) theory.