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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 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 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 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 title steroid, [(25 R )-spirost-4-en-3,6-dione, C 27 H 38 O 4 ], is obtained by oxidation of diosgenin, using the Jones reagent (CrO 3 /H 2 SO 4 ). The crystal structure was previously reported in space group P 2 1 2 1 2 1 , but nonetheless with the wrong absolute configuration and omitting positions for H atoms [Rajnikant et al. (2000 ▸). Mol. Cryst. Liq. Cryst. Sci. Technol. Sect. C , 12 , 101-110]. The diffraction data set reported herein is for a second polymorph in the same space group, as evidenced by simulated powder patterns. Both forms are characterized by a similar ortho-rhom-bic unit cell, and a similar arrangement of the mol-ecules in the crystal structure. However, the conformation of the A / B rings in the steroid nucleus is slightly modified, leading to the observed polymorphism., (© Guerrero-Luna et al. 2020.)

The title compound, C 22 H 33 NO 12 ·CHCl 3 , was obtained as a product of a double aza-Michael addition of hydroxyl-amine on a Chiron with a known absolute configuration. The enanti-opure compound crystallized as a chloro-form solvate, in space group P 1, and diffraction data were collected at room temperature with Ag K α radiation. The Flack parameter refined to x = -0.01 (16); however, the Flack and Watkin 2 AD plot clearly shows that differences between Friedel opposites (the D component of the plot) do not carry any reliable information about resonant scattering of Cl atoms, and are rather dominated by random and systematic errors. The R D factor calculated using 1941 acentric Friedel pairs is R D = 0.995. On the other hand, the 2 A component of the plot, related to average intensities of Friedel pairs, shows that data are of good quality ( R A = 0.069). This example illustrates that while using Ag K α radiation (λ = 0.56083 Å), scatterers heavier than Cl should be present in a chiral crystal in order to determine confidently the absolute structure of the crystal., (© Amaro Hernández et al. 2020.)

The crystal structure of (NH 4 ) 2 V 3 O 8 has been reported twice using single-crystal X-ray data [Theobald et al. (1984 ▸). J. Phys. Chem. Solids , 45 , 581-587; Range et al. (1988 ▸). Z. Naturforsch. Teil B , 43 , 309-317]. In both cases, the orientation of the ammonium cation in the asymmetric unit was poorly defined: in Theobald's study, the shape and dimensions were constrained for NH 4 , while in Range's study, H atoms were not included. In the present study, we collected a highly redundant data set for this ternary oxide, at 0.61 Å resolution, using Ag + , while in Range's study, H atoms were not included. In the present study, we collected a highly redundant data set for this ternary oxide, at 0.61 Å resolution, using Ag K α radiation. These accurate data reveal that the NH 4 + cation is disordered by rotation around a non-crystallographic axis. The rotation axis coincides with one N-H bond lying in the mirror m symmetry element of space-group type P 4 bm , and the remaining H sites were modelled over two disordered positions, with equal occupancy. It therefore follows that the NH 4 + cations filling the space available in the (001) layered structure formed by (V 3 O 8 ) 2- ions do not form strong N-H⋯O hydrogen bonds with the mixed-valent oxidovanadate(IV,V) anions. This feature could have consequences for the Li-ion inter-calation properties of this material, which is used as a cathode for supercapacitors., (© Pérez-Benítez and Bernès 2020.)

The structure of the tertiary amine tris-(1 H -benzimidazol-2-ylmeth-yl)amine (C 24 H 21 N 7 , abbreviated ntb) has been previously reported twice as solvates, namely the monohydrate and the aceto-nitrile-methanol-water (1/0.5/1.5) solvate, both with the tripodal conformation formed via multiple hydrogen bonds. Now, we report the tri-methanol adduct, ntb·3CH 3 OH, where the amine has the stair conformation featuring one benzimidazole group oriented in the opposite direction from the other two. The asymmetric unit contains one-half amine, completed through the mirror plane m in space group Pmn 2 1 to form the ntb mol-ecule, with the H atom for each imidazole moiety equally disordered between both N sites available in the imidazole ring. The asymmetric unit also contains one and a half methanol mol-ecules, one being placed in general position with the hy-droxy H atom disordered over two sites with occupancy ratio 1:1, while the other lies on the m mirror plane, and has thus its hy-droxy H atom disordered by symmetry. As in the previously reported solvates, all imine and amine groups of the ntb mol-ecules and the methanol mol-ecules are involved in N-H⋯O and O-H⋯N hydrogen bonds. In the title compound, however, the involved H atom is systematically a disordered H atom provided by an imidazole group or a methanol mol-ecule., (© Anzaldo-Olivares et al. 2020.)

The crystal structure of triphenylmethanol, C 19 H 16 O, has been redetermined using data collected at 295 and 153 K, and is compared to the model published by Ferguson et al. over 25 years ago [Ferguson et al. (1992). Acta Cryst. C48, 1272-1275] and that published by Serrano-González et al., using neutron and X-ray diffraction data [Serrano-González et al. (1999). J. Phys. Chem. B, 103, 6215-6223]. As predicted by these authors, the hydroxy groups are involved in weak intermolecular hydrogen bonds in the crystal, forming tetrahedral tetramers based on the two independent molecules in the asymmetric unit, one of which is placed on the threefold symmetry axis of the R-3 space group. However, the reliable determination of the hydroxy H-atom positions is difficult to achieve, for two reasons. Firstly, a positional disorder affects the full asymmetric unit, which is split over two sets of positions, with occupancy factors of ca 0.74 and 0.26. Secondly, all hydroxy H atoms are further disordered, either by symmetry, or through a positional disorder in the case of parts placed in general positions. We show that the correct description of the hydrogen-bonding scheme is possible only if diffraction data are collected at low temperature. The prochiral character of the hydrogen-bonded tetrameric supramolecular clusters leads to enantiomorphic three-dimensional graphs in each tetramer. The crystal is thus a racemic mixture of sup S and sup R motifs, consistent with the centrosymmetric nature of the R-3 space group., (open access.)

Transition-metal complexes bearing fluorinated phosphane and thiolate ligands has been an area of study in recent years and the chemical context of the current work is related to the metal-assisted functionalization of fluorinated derivatives. The cis and trans isomers of the square-planar complex bis[(pentafluorophenyl)diphenylphosphane-κP]bis(2,3,5,6-tetrafluorobenzenethiolato-κS)platinum(II), [Pt(C6HF4S)2{P(C6H5)2(C6F5)}2], have been crystallized from a single chromatographic fraction and characterized by X-ray diffraction analysis. The stabilization of the cis isomer results from weak intramolecular π-stacking interactions and possibly from the formation of a C-F...Pt contact, characterized by an F...Pt separation of 2.957 (6) Å. The natural bond orbital analysis (NBO) for this isomer confirms that the corresponding F → Pt charge transfer accounts for 6.92 kcal mol(-1) in the isomer stabilization. Such interactions are not present in the centrosymmetric trans isomer.

The title complex, catena-poly[di-μ3-acetato-κ(6)O:O:O'-tetra-μ2-acetato-κ(4)O:O;κ(4)O:O'-diaquabis(pyridine-κN)trimanganese(II)], [Mn3(CH3COO)6(C6H5N)2(H2O)2]n, is a true one-dimensional coordination polymer, in which the Mn(II) centres form a zigzag chain along [010]. The asymmetric unit contains two metal centres, one of which (Mn1) lies on an inversion centre, while the other (Mn2) is placed close to an inversion centre on a general position. Since all the acetates behave as bridging ligands, although with different μ2- and μ3-coordination modes, a one-dimensional polymeric structure is formed, based on trinuclear repeat units (Mn1...Mn2...Mn2'), in which the Mn2 and Mn2' sites are related by an inversion centre. Within this monomeric block, the metal-metal separations are Mn1...Mn2 = 3.36180 (18) Å and Mn2...Mn2' = 4.4804 (3) Å. Cation Mn1, located on an inversion centre, displays an [MnO6] coordination sphere, while Mn2, on a general position, has a slightly stronger [MnO5N] ligand field, as the sixth coordination site is occupied by a pyridine molecule. Both centres approximate an octahedral ligand field. The chains are parallel in the crystal structure and interact via hydrogen bonds involving coordinated water molecules. However, the shortest metal-metal separation between two chains [5.3752 (3) Å] is large compared with the intrachain interactions. These structural features are compatible with a single-chain magnet behaviour, as confirmed by preliminary magnetic studies.