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The title complex, [Cu(C 8 H 18 NO 5 )Cl] or [Cu(H 4 bis-tris-)Cl], was obtained starting from the previously reported [Cu(H 5 bis-tris-)Cl]Cl compound. The deprotonation of the amino-polyol ligand H 5 bis-tris {[bis-(2-hy-droxy-eth-yl)amino]-tris-(hy-droxy-meth-yl)methane, C 8 H 19 NO 5 } promotes the formation of a very strong O-H⋯O inter-molecular hydrogen bond, characterized by an H⋯O separation of 1.553 (19) Å and an O-H⋯O angle of 178 (4)°. The remaining hy-droxy groups are also engaged in hydrogen bonds, forming R 2 2 (8), R 4 4 (16), R 4 4 (20) and R 4 4 (22) ring motifs, which stabilize the triperiodic supra-molecular network., (© Fortis-Valera et al. 2024.)

The use of acetic acid (HOAc) in a reaction between CuCl 2 ·2H 2 O and secnid-azole, an active pharmaceutical ingredient useful in the treatment against a variety of anaerobic Gram-positive and Gram-negative bacteria, affords the title complex, [CuCl 2 (C 7 H 11 N 3 O 3 ) 2 ]. This compound was previously synthesized using ethanol as solvent, although its crystal structure was not reported [Betanzos-Lara et al. (2013 ▸). Inorg. Chim. Acta , 397 , 94-100]. In the mol-ecular complex, the Cu 2+ cation is situated at an inversion centre and displays a square-planar coordination environment. There is a hydrogen-bonded framework based on inter-molecular O-H⋯Cl inter-actions, characterized by H⋯Cl separations of 2.28 (4) Å and O-H⋯Cl angles of 175 (3)°. The resulting supra-molecular network is based on R 2 2 (18) ring motifs, forming chains in the [010] direction., (© Angel-Nieto et al. 2024.)

The title mol-ecule, C 12 H 15 NO 5 , is a methyl carbamate derivative obtained by reacting ( R )-2-phenyl-glycinol and methyl chloro-formate, with calcium hydroxide as heterogeneous catalyst. Supra-molecular chains are formed in the [100] direction, based on N-H⋯O hydrogen bonds between the amide and carboxyl-ate groups. These chains weakly inter-act in the crystal, and the phenyl rings do not display significant π-π inter-actions., (© Mendoza Herrera et al. 2024.)

The chemical formula of the title compound, 2C 17 H 17 N 4 + ·2C 7 H 5 O 5 - ·C 17 H 16 N 4 ·2.94C 4 H 8 O 2 , was established by X-ray diffraction of a single-crystal obtained by reacting 1,3-bis-(benzimidazol-2-yl)propane ( L ) and gallic acid (HGal) in ethyl acetate. The mol-ecular structure can be described as a salt (H L ) + (Gal) - co-crystallized with a mol-ecule L , with a stoichiometric relation of 2:1. Moreover, large voids in the crystal are filled with ethyl acetate, the amount of which was estimated by using a solvent mask during structure refinement, affording the chemical formula (H L + ·Gal - ) 2 · L ·(C 4 H 8 O 2 ) 2.94 . The arrangement of components in the crystal is driven by O-H⋯O, N-H⋯O and O-H⋯N hydrogen bonds rather than by π-π or C-H⋯π inter-actions. In the crystal, mol-ecules and ions shape the boundary of cylindrical tunnels parallel to [100] via R (rings) and D (discrete) supra-molecular motifs. These voids, which account for about 28% of the unit-cell volume, contain disordered solvent mol-ecules., (© Palacios Rodríguez et al. 2023.)

The title compound, C 29 H 46 O 3 , is a steroid synthesized through a rearrangement of a sarsasapogenin derivative in acidic medium. The newly formed ring F is a tetra-hydro-2 H -pyran heterocycle substituted by two methyl groups placed in equatorial positions. This ring displays a chair conformation, while di-hydro-furan ring E , to which it is bonded, has an envelope conformation. The mol-ecules are associated by weak O-H⋯O hydrogen bonds to form chains running in the [101] direction in the crystal., (© Guerrero-Luna et al. 2023.)

The title salt, C 14 H 14 N 3 O 4 S 2 + ·Cl - [systematic name: 2-(4-hy-droxy-2-methyl-1,1-dioxo-1,2-benzo-thia-zine-3-amido)-5-methyl-1,3-thia-zol-3-ium chloride] is the hydro-chloride derivative of meloxicam, a drug used to treat pain and inflammation in rheumatic disorders and osteoarthritis. Although its mol-ecular structure is similar to that previously reported for the hydro-bromide analogue, both salts are not isomorphous. Different crystal structures originate from a conformational modification, arising from a degree of rotational freedom for the thia-zolium ring in the cations. By taking as a reference the conformation of meloxicam, the thia-zolium ring is twisted by 10.96 and -16.70° in the hydro-chloride and hydro-bromide salts, while the 1,2-benzo-thia-zine core is a rigid scaffold. This behaviour could explain why meloxicam is a polymorphous compound., (© Flores Manuel et al. 2023.)

The plastic phase of cyclohexane (polymorph I) was studied by Kahn and co-workers, without achieving a satisfactory determination of the atomic coord-inates [Kahn et al. (1973). Acta Cryst . B 29 , 131-138]. The positions of the C atoms cannot be determined directly as a consequence of the disorder in a high-symmetry space group, an inherent feature of plastic materials. Given this situation, the building of a polyhedron describing the disorder was the main tool for determining the molecular structure in the present work. Based on the shape of reflections {111}, {200} and {113} in space group Fm 3 m , we assumed that cyclohexane is disordered through the action of rotation group 432. The polyhedral cluster of disordered molecules is then a rhombic dodecahedron centred on the nodes of an fcc Bravais lattice. The vertices of this polyhedron are the positions of C atoms for the cyclohexane molecule, which is disordered over 24 positions. With such a model, the asymmetric unit is reduced to two C atoms placed on special positions, and an acceptable fit between the observed and calculated structure factors is obtained., (© Bernes and Camargo 2023.)

The title mol-ecule, C 14 H 14 O 6 , is based on a benzene core di-substituted by allyl carbonate groups in the para positions. The mol-ecule is placed on an inversion centre, and the substituents are twisted with respect to the central benzene ring plane. The crystal structure does not include significant inter-molecular inter-actions other than weak C-H⋯O contacts between CH groups in the benzene ring and carbonate O atoms., (© López-Velázquez et al. 2023.)

The title Sn IV complex, [Sn(C 6 H 5 ) 3 Cl(C 18 H 15 O 4 P)], is a formal adduct between triphenyl phosphate (PhO) 3 P=O and the stannane derivative chlorido-tri-phenyl-tin, SnPh 3 Cl. The structure refinement reveals that this mol-ecule displays the largest Sn-O bond length for compounds including the X =O→SnPh 3 Cl fragment ( X = P, S, C, or V), 2.6644 (17) Å. However, an AIM topology analysis based on the wavefunction calculated from the refined X-ray structure shows the presence of a bond critical point (3,-1), lying on the inter-basin surface separating the coordinated phosphate O atom and the Sn atom. This study thus shows that an actual polar covalent bond is formed between (PhO) 3 P=O and SnPh 3 Cl moieties., (© Pouye et al. 2023.)

The title compound, C 20 H 16 N 2 O 6 (systematic name: 4-hy-droxy-phenyl N -{4-[(4-hy-droxy-phen-oxy-carbon-yl)amino]-phen-yl}carbamate), contains two urethane groups substituting the central benzene ring in para positions. The mol-ecule is centrosymmetric, and displays a twisted conformation for the three aromatic rings [the dihedral angle between central benzene ring and the urethane group is 33.4 (6)°, and that between the latter and the terminal ring is 65.1 (1)°]. In the crystal, a three-dimensional framework is formed through O-H⋯O and N-H⋯O hydrogen bonds involving the hy-droxy and urethane functional groups, respectively., (© Martínez-de la Luz et al. 2022.)

The title metal-organic polymer, catena-poly[[(5,5'-dimethyl-2,2'-bipyridine-κ 2 N,N')iron(II)]-di-μ-azido-κ 2 N 1 :N 3 -[(5,5'-dimethyl-2,2'-bipyridine-κ 2 N,N')iron(II)]-di-μ-azido-κ 2 N 1 :N 1 ], [Fe(N 3 ) 2 (C 12 H 12 N 2 )] n , features alternating μ-1,1 (end-on mode of coordination) and μ-1,3 (end-to-end mode of coordination) double azide bridges, forming chains running in the [100] direction. The octahedral coordination geometry around the Fe II centre is completed by a bidentate 5,5'-dimethyl-2,2'-bipyridine ligand. Two polymorphs for this compound were obtained from the crude reaction product, the first in the space group P-1 and the other in P2 1 /c. The molecular and crystal structures are very similar for both forms, the main difference being that the eight-membered Fe(μ-1,3-N 3 ) 2 Fe metallacycle formed with end-to-end azide ligands has a nearly flat conformation in the triclinic form and a chair conformation in the monoclinic form. In spite of this geometric difference, both forms have the same density, the same packing index and similar arrangements of the one-dimensional chains in the crystal. As a consequence, they also share very similar Hirshfeld surfaces and fingerprint plots. However, a density functional theory (DFT) computational study showed that the monoclinic form is more stable than the triclinic form by ca 30.5 kJ mol -1 .

The title compound, (C 4 H 12 N 5 ) 4 (C 2 H 7 N 4 O) 2 [V 10 O 28 ]·4H 2 O, is a by-product obtained by reacting ammonium metavanadate(V), metformin hydro-chloride and acetic acid in the presence of sodium hypochlorite, at pH = 5. The crystal structure comprises a deca-vanadate(V) anion (V 10 O 28 ) 6- lying on an inversion centre in space group P , while cations and solvent water mol-ecules are placed in general positions, surrounding the anion, and forming numerous N-H⋯O and O-H⋯O hydrogen bonds. Metforminium (C 4 H 12 N 5 ) + and guanylurea (C 2 H 7 N 4 O) + cations display the expected shape. Inter-estingly, in physiology the latter cation is known to be the main metabolite of the former one. The reported structure thus supports the role of sodium hypochlorite as an oxidizing reagent being able to degrade metformin hydro-chloride to form guanylurea., (© Pérez-Benítez et al. 2022.)

The synthesis of new chiral highly functionalized zwitterionic bicyclic lactams starting from acyclic β-enaminoesters derived from ( R )-(-)-2-phenylglycinol is described. The key step involved an intramolecular non-classical Corey-Chaykovsky ring-closing reaction of the corresponding sulfonium salts derived from β-enaminoesters. This methodology permits the generation of two or three new stereogenic centers with high diastereoselectivity. The utility of these intermediates was demonstrated by the stereocontrolled total synthesis of cis -4-hydroxy-2-methyl piperidine and its corresponding pipecolic acid derivative., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The stereoselective cyclization of a C-16 acetylated 22,26-dioxocholestene derivative to give the spirostane E and F rings, under alkaline conditions, yields exclusively the (26R)-26-hydroxydiosgenin. Both experimental and computational data support the formation of a single diastereoisomer. The effect of diosgenin and (26R)-26-hydroxydiosgenin on rat ovary is also investigated., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The mol-ecular structure of the title compound {systematic name: 1,3-di-cyclo-hexyl-1-[2-(1,3-dioxo-2,3-di-hydro-1 H -isoindol-2-yl)acet-yl]urea}, C 23 H 29 N 3 O 4 , derived from N , N '-di-cyclo-hexyl-urea, shows that the tertiary N atom substituted by a cyclo-hexyl and phthaloylglycyl groups adopts a perfectly planar geometry (bond-angle sum = 360.0°). In the same way as for N , N '-di-cyclo-hexyl-urea, the extended structure of the title compound features N-H⋯O hydrogen bonds, which generate chains of mol-ecules running in the [001] direction., (© Bernès and Hernández-Linares 2021.)

The title compound, (NH 4 ) 4 (C 4 H 12 N 5 ) 2 [V 10 O 28 ]·6H 2 O, crystallizes with the deca-vanadate anion placed on an inversion centre in space group P . This anion is surrounded by a first shell of ammonium cations and water mol-ecules, forming efficient N-H⋯O and O-H⋯O hydrogen bonds. A second shell includes metforminium monocations with a twisted geometry, also forming numerous inter-molecular hydrogen bonds. The complex three-dimensional network of non-covalent inter-actions affords a crystal structure in which the cations and anions are densely packed., (© Polito-Lucas et al. 2021.)

The crystal structure model for potassium tri-iodido-mercurate(II) monohydrate, K[HgI 3 ]·H 2 O, based on single-crystal data, was reported 50 years ago [Nyqvist & Johansson (1971 ▸). Acta Chem. Scand . 25 , 1615-1629]. We have now redetermined this structure with X-ray diffraction data at 0.70 Å resolution collected at 153 K using Ag K α radiation. Combined quantum mechanical methods ( ORCA ) and computation of non-spherical scattering form factors ( NoSpherA2 ) allowed the refinement of the shape of the water mol-ecule with anisotropic H atoms, despite the presence of heavy elements in the crystal. The refined shape of the water mol-ecule via this Hirshfeld refinement is close to that determined for liquid water by neutron diffraction experiments. Moreover, the Laplacian of the electron density clearly shows how electron density accumulates along the O-H σ-valence bonds in the water mol-ecule., (© Chocolatl Torres et al. 2021.)

In this work, we report the synthesis of two new azasteroids through the modification of the A and B rings of diosgenin 1. The 4-azasteroid derivative 12 was prepared in three steps using the α,β-insaturated-3-keto compound 11 as a precursor, which was first oxidized with KMnO 4 /KIO 4 followed by an oxidative cleavage of ring A, and subsequently cyclized with an ammonium salt, under focused microwave irradiation for a short time of 3 min. A second azasteroid was synthesized, for which the key step was the Beckmann rearrangement of ring B of the oxime 16, affording the lactam-type enamide 17 in good yield. The methodologies developed for the synthesis of the precursors derivatives 10 and 11 contribute to improved yields, compared to those reported in the literature. The biological activity of the azasteroidal compounds 12 and 17 and their precursors has been evaluated in cervical cancer cells (HeLa), colon (HCT-15), and triple negative breast cancer (MDA-MB-231) lines., (Copyright © 2020 Elsevier Inc. All rights reserved.)