The title compound, C12H15N3O2S, adopts an E configuration with respect to the C=N bond. The propionate group adopts an anti­periplanar (ap) conformation. There are short intra­molecular N—H⋯N and C—H⋯O contacts, forming S(5) and S(6) ring motifs, respectively. In the crystal, mol­ecules are connected into ribbons extending parallel to [010] by pairs of N—H⋯S inter­actions, forming rings with R22(8) graph-set motifs, and by pairs of C—H⋯S inter­actions, where rings with the graph-set motif R21(7) are observed. The O atom of the carbonyl group is disordered over two positions, with a refined occupancy ratio of 0.27 (2):0.73 (2). The studied crystal consisted of two domains.

In the title compound, C24H21NO3S, the cyclopentene ring adopts an envelope conformation. In the crystal, mol­ecules are linked by C—H⋯π inter­actions, forming ribbons along the a axis. Inter­molecular C—H⋯O hydrogen bonds connect these ribbons to each other, forming layers parallel to the (0overline{1}1) plane. The mol­ecular packing is strengthened by van der Waals inter­actions between the layers. The inter­molecular contacts were qu­anti­fied using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative contributions of the contacts to the crystal packing to be H⋯H 46.0%, C⋯H/H⋯C 21.1%, O⋯H/H⋯O 20.6% and S⋯H/H⋯S 9.0%.

The title compound, [Co(C3H4N2)(C30H30N10)](BF4)2, is a five-coordinate CoII complex based on the neutral ligands tris­[(1-benzyl­triazol-4-yl)meth­yl]amine (tbta) and imidazole. It exhibits a distorted trigonal bipyramidal geometry in which the equatorial positions are occupied by the three N-atom donors from the triazole rings of the tripodal tbta ligand. The apical amine N-atom donor of tbta and the N-atom donor of the imidazole ligand occupy the axial positions of the coordination sphere. Two tetra­fluoro­borate anions provide charge balance in the crystal.

Two 2,4,6-tri­methyl­aniline-based trifuloro­methane­sulfonate (tri­fluoro­methane­sulfonate) salts were synthesized and characterized by single-crystal X-ray diffraction. N,2,4,6-Tetra­methyl­anilinium tri­fluoro­methane­sulfonate, [C10H14NH2+][CF3O3S−] (1), was synthesized via methyl­ation of 2,4,6-tri­methyl­aniline. N-Iso­propyl­idene-N,2,4,6-tetra­methyl­anilinium tri­fluoro­meth­ane­sulfonate, [C13H20N+][CF3O3S−] (2), was synthesized in a two-step reaction where the imine, N-iso­propyl­idene-2,4,6-tri­methyl­aniline, was first prepared via a dehydration reaction to form the Schiff base, followed by methyl­ation using methyl tri­fluoro­methane­sulfonate to form the iminium ion. In compound 1, both hydrogen bonding and π–π inter­actions form the main inter­molecular inter­actions. The primary inter­action is a strong N—H⋯O hydrogen bond with the oxygen atoms of the tri­fluoro­methane­sulfonate anions bonded to the hydrogen atoms of the ammonium nitro­gen atom to generate a one-dimensional chain. The [C10H14NH2+] cations form dimers where the benzene rings form a π–π inter­action with a parallel-displaced geometry. The separation distance between the calculated centroids of the benzene rings is 3.9129 (8) Å, and the inter­planar spacing and ring slippage between the dimers are 3.5156 (5) and 1.718 Å, respectively. For 2, the [C13H20N+] cations also form dimers as in 1, but with the benzene rings highly slipped. The distance between the calculated centroids of the benzene rings is 4.8937 (8) Å, and inter­planar spacing and ring slippage are 3.3646 (5) and 3.553 Å, respectively. The major inter­molecular inter­actions in 2 are instead a series of weaker C—H⋯O hydrogen bonds [C⋯O distances of 3.1723 (17), 3.3789 (18), and 3.3789 (18) Å], an inter­action virtually absent in the structure of 1. Fluorine atoms are not involved in strong directional inter­actions in either structure.

The calixarenes, 5,17-di­bromo-26,28-dihy­droxy-25,27-dipropynyloxycalix[4]arene (C34H26Br2O4, 1), 5,17-di­bromo-26,28-dipropoxy-25,27-dipropynyloxycalix[4]arene (C40H38Br2O4, 2) and 25,27-bis­(2-azido­eth­oxy)-5,17-di­bromo-26,28-di­hydroxy­calix[4]arene (C32H28Br2N6O4, 3) possess a pinched cone mol­ecular shape for 1 and 3, and a 1,3-alternate shape for compound 2. In calixarenes 1 and 3, the cone conformations are additionally stabilized by intra­molecular O—H⋯O hydrogen bonds, while in calixarene 2 intra­molecular Br⋯Br inter­actions consolidate the 1,3-alternate mol­ecular conformation. The dense crystal packing of the cone dialkyne 1 is a consequence of π–π, C—H⋯π and C—H⋯O inter­actions. In the crystal of the diazide 3, there are large channels extending parallel to the c axis, which are filled by highly disordered CH2Cl2 solvent mol­ecules. Their contribution to the intensity data was removed by the SQUEEZE procedure that showed an accessible void volume of 585 Å3 where there is room for 4.5 CH2Cl2 solvent mol­ecules per unit cell. Rigid mol­ecules of the 1,3-alternate calixarene 2 form a columnar head-to-tail packing parallel to [010] via van der Waals inter­actions, and the resulting columns are held together by weak C—H⋯π contacts.

The complex [Pt(C9H6NO)Cl(C2H4)], (I), was synthesized and structurally characterized by ESI mass spectrometry, IR, NMR spectroscopy, DFT calculations and X-ray diffraction. The results showed that the deprotonated 8-hy­droxy­quinoline (C9H6NO) coordinates with the PtII atom via the N and O atoms while the ethyl­ene coordinates in the η2 manner and in the trans position compared to the coordinating N atom. The crystal packing is characterized by C—H⋯O, C—H⋯π, Cl⋯π and Pt⋯π inter­actions. Complex (I) showed high selective activity against Lu-1 and Hep-G2 cell lines with IC50 values of 0.8 and 0.4 µM, respectively, 54 and 33-fold more active than cisplatin. In particular, complex (I) is about 10 times less toxic to normal cells (HEK-293) than cancer cells Lu-1 and Hep-G2. Furthermore, the reaction of complex (I) with guanine at the N7 position was proposed and investigated using the DFT method. The results indicated that replacement of the ethyl­ene ligand with guanine is thermodynamically more favorable than the Cl ligand and that the reaction occurs via two consecutive steps, namely the replacement of ethyl­ene with H2O and the water with the guanine mol­ecule.

The title compound, C12H10N2O3, was obtained by the de­acetyl­ation reaction of 1-(6-amino-5-nitro­naphthalen-2-yl)ethanone in a concentrated sulfuric acid methanol solution. The mol­ecule comprises a naphthalene ring system bearing an acetyl group (C-3), an amino group (C-7), and a nitro group (C-8). In the crystal, the mol­ecules are assembled into a two-dimensional network by N⋯H/H⋯N and O⋯H/H⋯O hydrogen-bonding inter­actions. n–π and π–π stacking inter­actions are the dominant inter­actions in the three-dimensional crystal packing. Hirshfeld surface analysis indicates that the most important contributions are from O⋯H/H⋯O (34.9%), H⋯H (33.7%), and C⋯H/H⋯C (11.0%) contacts. The energies of the frontier mol­ecular orbitals were computed using density functional theory (DFT) calculations at the B3LYP-D3BJ/def2-TZVP level of theory and the LUMO–HOMO energy gap of the mol­ecule is 3.765 eV.

The new palladium(II) complex, [Pd(C16H16N4O3)2](CF3COO)2·2CF3COOH, crystallizes in the triclinic space group Poverline{1} with the asymmetric unit containing half the cation (PdII site symmetry Ci), one tri­fluoro­actetate anion and one co-crystallized tri­fluoro­acetic acid mol­ecule. Two neutral chelating 2-[5-(3,4,5-tri­meth­oxy­phen­yl)-4H-1,2,4-triazol-3-yl]pyridine ligands coordinate to the PdII ion through the triazole-N and pyridine-N atoms in a distorted trans-PdN4 square-planar configuration [Pd—N 1.991 (2), 2.037 (2) Å; cis N—Pd—N 79.65 (8), 100.35 (8)°]. The complex cation is quite planar, except for the methoxo groups (δ = 0.117 Å for one of the C atoms). The planar configuration is supported by two intra­molecular C—H⋯N hydrogen bonds. In the crystal, the π–π-stacked cations are arranged in sheets parallel to the ab plane that are flanked on both sides by the tri­fluoro­acetic acid–tri­fluoro­acetate anion pairs. Apart from classical N/O—H⋯O hydrogen-bonding inter­actions, weak C—H⋯F/N/O contacts consolidate the three-dimensional architecture. Both tri­fluoro­acetic moieties were found to be disordered over two resolvable positions with a refined occupancy ratio of 0.587 (1):0.413 (17) and 0.530 (6):0.470 (6) for the protonated and deprotonated forms, respectively.

In the title compound, C15H13NO3S, the mol­ecular conformation is stable with the intra­molecular O—H⋯O hydrogen bond forming a S(7) ring motif. In the crystal, mol­ecules are connected by C—H⋯O hydrogen bonds, forming C(8) chains running along the a-axis direction. Cohesion of the packing is provided by weak van der Waals inter­actions between the chains. A Hirshfeld surface analysis was undertaken to investigate and qu­antify the inter­molecular inter­actions. The thio­phene ring is disordered in a 0.9466 (17):0.0534 (17) ratio over two positions rotated by 180°.

The few examples of structures containing the 2-chloro-N,N-di­methyl­ethan-1-aminium or 3-chloro-N,N-di­methyl­propan-1-aminium cations show a compet­ition between gauche and anti conformations for the chloro­alkyl chain. To explore further the conformational landscape of these cations, and their possible use as mol­ecular switches, the title salts, (C4H11ClN)2[CoCl4] and (C4H11ClN)2[ZnCl4], were prepared and structurally characterized. Details of both structures are in close agreement. The inorganic complex exhibits a slightly flattened tetra­hedral geometry that likely arises from bifurcated N—H hydrogen bonds from the organic cations. The alkyl chain of the cation is disordered between gauche and anti conformations with the gauche conformation occupancy refined to 0.707 (2) for the cobaltate. The gauche conformation places the terminal Cl atom at a tetra­hedral face of the inorganic complex with a contact distance of 3.7576 (9) Å to the Co2+ center. The anti conformation places the terminal Cl atom at a contact distance to a neighboring anti conformation terminal Cl atom that is ∼1 Å less than the sum of the van der Waals radii. Thus, if the anti conformation is present at a site, then the nearest neighbor must be gauche. DFT geometry optimizations indicate the gauche conformation is more stable in vacuo by 0.226 eV, which reduces to 0.0584 eV when calculated in a uniform dielectric. DFT geometry optimizations for the unprotonated mol­ecule indicate the anti conformation is stabilized by 0.0428 eV in vacuo, with no strongly preferred conformation in uniform dielectric, to provide support to the notion that this cation could function as a mol­ecular switch via deprotonation.

In the title compound, C6H4BrF3N4O2, the oxa­diazole ring is essentially planar with a maximum deviation of 0.003 (2) Å. In the crystal, mol­ecular pairs are connected by N—H⋯N hydrogen bonds, forming dimers with an R22(8) motif. The dimers are linked into layers parallel to the (10overline{4}) plane by N—H⋯O hydrogen bonds. In addition, C—O⋯π and C—Br⋯π inter­actions connect the mol­ecules, forming a three-dimensional network. The F atoms of the tri­fluoro­methyl group are disordered over two sites in a 0.515 (6): 0.485 (6) ratio. The inter­molecular inter­actions in the crystal structure were investigated and qu­anti­fied using Hirshfeld surface analysis.

The title mol­ecule, C18H26O4, consists of two symmetrical halves related by the inversion centre at the mid-point of the central –C—C– bond. The hexene ring adopts an envelope conformation. In the crystal, the mol­ecules are connected into dimers by C—H⋯O hydrogen bonds with R22(8) ring motifs, forming zigzag ribbons along the b-axis direction. According to a Hirshfeld surface analysis, H⋯H (68.2%) and O⋯H/H⋯O (25.9%) inter­actions are the most significant contributors to the crystal packing. The contribution of some disordered solvent to the scattering was removed using the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9–18] in PLATON. The solvent contribution was not included in the reported mol­ecular weight and density.

In the title compound, C31H24N4O2, the di­hydro­quinoxaline units are both essentially planar with the dihedral angle between their mean planes being 64.82 (4)°. The attached phenyl rings differ significantly in their rotational orientations with respect to the di­hydro­quinoxaline planes. In the crystal, one set of C—H⋯O hydrogen bonds form chains along the b-axis direction, which are connected in pairs by a second set of C—H⋯O hydrogen bonds. Two sets of π-stacking inter­actions and C—H⋯π(ring) inter­actions join the double chains into the final three-dimensional structure.

The cis- form of di­amino­dibenzo­cyclo­octane (DADBCO, C16H18N2) is of inter­est as a negative coefficient of thermal expansion (CTE) material. The crystal structure was determined through single-crystal X-ray diffraction at 100 K and is presented herein.

The synthesis, crystallization and characterization of a tri­fluoro­methane­sulfonate salt of 5,10,15,20-tetra­kis­(1-benzyl­pyridin-1-ium-4-yl)-21H,23H-por­phy­rin, C68H54N84+·4CF3SO3−·4H2O, 1·OTf, are reported in this work. The reaction between 5,10,15,20-tetra­kis­(pyridin-4-yl)-21H,23H-porphyrin and benzyl bromide in the presence of 0.1 equiv. of Ca(OH)2 in CH3CN under reflux with an N2 atmosphere and subsequent treatment with silver tri­fluoro­methane­sulfonate (AgOTf) salt produced a red–brown solution. This reaction mixture was filtered and the solvent was allowed to evaporate at room temperature for 3 d to give 1·OTf. Crystal structure determination by single-crystal X-ray diffraction (SCXD) revealed that 1·OTf crystallizes in the space group P21/c. The asymmetric unit contains half a porphyrin mol­ecule, two tri­fluoro­methane­sulfonate anions and two water mol­ecules of crystallization. The macrocycle of tetra­pyrrole moieties is planar and unexpectedly it has coordinated CaII ions in occupational disorder. This CaII ion has only 10% occupancy (C72H61.80Ca0.10F12N8O16S4). The pyridinium rings bonded to methyl­ene groups from porphyrin are located in two different arrangements in almost orthogonal positions between the plane formed by the porphyrin and the pyridinium rings. The crystal structure features cation⋯π inter­actions between the CaII atom and the π-system of the phenyl ring of neighboring mol­ecules. Both tri­fluoro­methane­sulfonate anions are found at the periphery of 1, forming hydrogen bonds with water mol­ecules.

In the title compound, C19H17NO5S, the cyclo­hexene ring adopts nearly an envelope conformation. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, forming a three-dimensional network. In addition, C—H⋯π inter­actions connect the mol­ecules by forming layers parallel to the (010) plane. According to the Hirshfeld surface analysis, H⋯H (36.9%), O⋯H/H⋯O (31.0%), C⋯H/H⋯C (18.9%) and S⋯H/H⋯S (7.9%) inter­actions are the most significant contributors to the crystal packing.

The chemical reaction of 4-bromo­benzoyl­chloride and 2-amino­thia­zole in the presence of potassium thio­cyanate yielded a white solid formulated as C15H10BrN3OS2, which consists of 4-bromo­benzamido and 2-benzo­thia­zolyl moieties connected by a thio­urea group. The 4-bromo­benzamido and 2-benzo­thia­zolyl moieties are in a trans conformtion (sometimes also called s-trans due to the single bond) with respect to the N—C bond. The dihedral angle between the mean planes of the 4-bromo­phenyl and the 2-benzo­thia­zolyl units is 10.45 (11)°. The thio­urea moiety, —C—NH—C(=S) —NH— fragment forms a dihedral angle of 8.64 (12)° with the 4-bromo­phenyl ring and is almost coplanar with the 2-benzo­thia­zolyl moiety, with a dihedral angle of 1.94 (11)°. The mol­ecular structure is stabilized by intra­molecular N—H⋯O hydrogen bonds, resulting in the formation of an S(6) ring. In the crystal, pairs of adjacent mol­ecules inter­act via inter­molecular hydrogen bonds of type C—H⋯N, C—H⋯S and N—H⋯S, resulting in mol­ecular layers parallel to the ac plane.

The structural characterization is reported of the supra­molecular complex between the tetra­quinoxaline-based cavitand 2,8,14,20-tetra­hexyl-6,10:12,16:18,22:24,4-O,O'-tetra­kis­(quinoxaline-2,3-di­yl)calix[4]resorcinarene (QxCav) with benzo­nitrile. The complex, of general formula C84H80N8O8·2C7H5N, crystallizes in the space group Poverline{1} with two independent mol­ecules in the asymmetric unit, displaying very similar geometrical parameters. For each complex, one of the benzo­nitrile mol­ecules is engulfed inside the cavity, while the other is located among the alkyl legs at the lower rim. The host and the guests mainly inter­act through weak C—H⋯π, C—H⋯N and dispersion inter­actions. These inter­actions help to consolidate the formation of supra­molecular chains running along the crystallographic b-axis direction.

The title compound, [Co(NCS)2(C6H7N)4] or Co(NCS)2(4-methyl­pyridine)4, was prepared by the reaction of Co(NCS)2 with 4-methyl­pyridine in water and is isotypic to one of the polymorphs of Ni(NCS)2(4-methyl­pyridine)4 [Kerr & Williams (1977). Acta Cryst. B33, 3589–3592 and Soldatov et al. (2004). Cryst. Growth Des. 4, 1185–1194]. Comparison of the experimental X-ray powder pattern with that calculated from the single-crystal data proves that a pure phase has been obtained. The asymmetric unit consists of one CoII cation, two crystallographically independent thio­cyanate anions and four independent 4-meth­yl­pyridine ligands, all located in general positions. The CoII cations are sixfold coordinated to two terminally N-bonded thio­cyanate anions and four 4-methyl­pyridine coligands within slightly distorted octa­hedra. Between the complexes, a number of weak C—H⋯N and C—H⋯S contacts are found. This structure represent a polymorphic modification of Co(NCS)2(4-methyl­pyridine)4 already reported in the CCD [Harris et al. (2003). NASA Technical Reports, 211890]. In contrast to this form, the crystal structure of the new polymorph shows a denser packing, indicating that it is thermodynamically stable at least at low temperatures. Thermogravimetric and differential thermoanalysis reveal that the title compound starts to decomposes at about 100°C and that the coligands are removed in separate steps without any sign of a polymorphic transition before decomposition.

The reaction of CoBr2, KNCSe and 2-methyl­pyridine N-oxide (C6H7NO) in ethanol leads to the formation of crystals of [Co(NCSe)2(C6H7NO)3] (1) and [Co(NCSe)2(C6H7NO)4] (2) from the same reaction mixture. The asymmetric unit of 1 is built up of one CoII cation, two NCSe− iso­seleno­cyanate anions and three 2-methyl­pyridine N-oxide coligands, with all atoms located on general positions. The asymmetric unit of 2 consists of two cobalt cations, four iso­seleno­canate anions and eight 2-methyl­pyridine N-oxide coligands in general positions, because two crystallographically independent complexes are present. In compound 1, the CoII cations are fivefold coordinated to two terminally N-bonded anionic ligands and three 2-methyl­pyridine N-oxide coligands within a slightly distorted trigonal–bipyramidal coordination, forming discrete complexes with the O atoms occupying the equatorial sites. In compound 2, each of the two complexes is coordinated to two terminally N-bonded iso­seleno­cyanate anions and four 2-methyl­pyridine N-oxide coligands within a slightly distorted cis-CoN2O4 octa­hedral coordination geometry. In the crystal structures of 1 and 2, the complexes are linked by weak C—H⋯Se and C—H⋯O contacts. Powder X-ray diffraction reveals that neither of the two compounds were obtained as a pure crystalline phase.

In the title mol­ecular salt, (C12H14N2)[CoCl4], the dihedral angle between the pyridine rings of the cation is 52.46 (9)° and the N—C—C—N torsion angle is −128.78 (14)°, indicating that the ring nitro­gen atoms are in anti-clinal conformation. The Cl—Co—Cl bond angles in the anion span the range 105.46 (3)–117.91 (2)°. In the extended structure, the cations and anions are linked by cation-to-anion N—H⋯Cl and C—H⋯Cl inter­actions, facilitating the formation of R44(18) and R44(20) ring motifs. Furthermore, the crystal structure features weak anion-to-cation Cl⋯π inter­actions [Cl⋯π = 3.4891 (12) and 3.5465 (12) Å]. Hirshfeld two-dimensional fingerprint plots revealed that the most significant inter­actions are Cl⋯H/H⋯Cl (45.5%), H⋯H (29.0%), Cl⋯C/C⋯Cl (7.8%), Cl⋯N/N⋯Cl (3.5%), Cl⋯Cl (1.4) and Co⋯H (1%) contacts.

The synthesis, crystal structure, and a Hirshfeld surface analysis of tris­{N,N-diethyl-N'-[(4-nitro­phen­yl)(oxo)meth­yl]carbamimido­thio­ato}cobalt(III) conducted at 180 K are presented. The complex consists of three N,N-diethyl-N'-[(4-nitro­benzene)(oxo)meth­yl]carbamimido­thio­ato ligands, threefold sym­metric­ally bonded about the CoIII ion, in approximately octa­hedral coordination, which generates a triple of individually near planar metallacyclic (Co—S—C—N—C—O) rings. The overall geometry of the complex is determined by the mutual orientation of each metallacycle about the crystallographically imposed threefold axis [dihedral angles = 81.70 (2)°] and by the dihedral angles between the various planar groups within each asymmetric unit [metallacycle to benzene ring = 13.83 (7)°; benzene ring to nitro group = 17.494 (8)°]. The complexes stack in anti-parallel columns about the overline{3} axis of the space group (Poverline{3}), generating solvent-accessible channels along [001]. These channels contain ill-defined, multiply disordered, partial-occupancy solvent. Atom–atom contacts in the crystal packing predominantly (∼96%) involve hydrogen, the most abundant types being H⋯H (36.6%), H⋯O (31.0%), H⋯C (19.2%), H⋯N (4.8%), and H⋯S (4.4%).

The oxidation of me­thionyl peptides can contribute to increased biological (oxidative) stress and development of various inflammatory diseases. The conformation of peptides has an important role in the mechanism of oxidation and the inter­mediates formed in the reaction. Herein, the crystal structures of the isomeric dipeptides Gly-Met (Gly = glycine and Met = me­thio­nine) and Met-Gly, both C7H14N2O3S, are reported. Both mol­ecules exist in the solid state as zwitterions with nominal proton transfer from the carb­oxy­lic acid to the primary amine group. The Gly-Met mol­ecule has an extended backbone structure, while Met-Gly has two nearly planar regions kinked at the C atom bearing the NH3 group. In the crystals, both structures form extensive three-dimensional hydrogen-bonding networks via N—H⋯O and bifurcated N—H⋯(O,O) hydrogen bonds having N⋯O distances in the range 2.6619 (13)–2.8513 (13) Å for Gly-Met and 2.6273 (8)–3.1465 (8) Å for Met-Gly.

Crystal formation of caesium thallium chloride phospho­tungstates, Cs9(TlCl6)(PW12O40)2·9CsCl showcases the ability to capture and crystallize octa­hedral complexes via the use of polyoxometalates (POMs). The large number of caesium chlorides allows for the POM [α-PW12O40]3− to arrange itself in a cubic close-packing lattice extended framework, in which the voids created enable the capture of the [TlCl6]3− complex.

This study presents the synthesis, characterization and Hirshfeld surface analysis of a small organic ammonium salt, C2H7BrN+·Br−. Small cations like the one in the title compound are considered promising components of hybrid perovskites, crucial for optoelectronic and photovoltaic applications. While the incorporation of this organic cation into various hybrid perovskite structures has been explored, its halide salt counterpart remains largely uninvestigated. The obtained structural results are valuable for the synthesis and phase analysis of hybrid perovskites. The title compound crystallizes in the solvent-free form in the centrosymmetric monoclinic space group P21/c, featuring one organic cation and one bromide anion in its asymmetric unit, with a torsion angle of −64.8 (2)° between the ammonium group and the bromine substituent, positioned in a gauche conformation. The crystal packing is predominantly governed by Br⋯H inter­actions, which constitute 62.6% of the overall close atom contacts.

The title compound, [Re(C17H22N3O2S)(CO)3] is a net neutral fac-Re(I)(CO)3 complex of the 4-methyl­biphenyl sulfonamide derivatized di­ethyl­enetri­amine ligand. The NNN-donor monoanionic ligand coordinates with the Re core in tridentate fashion, establishing an inner coordination sphere resulting in a net neutral complex. The complex possesses pseudo-octa­hedral geometry where one face of the octa­hedron is occupied by three carbonyl ligands and the other faces are occupied by one sp2 nitro­gen atom of the sulfonamide group and two sp3 nitro­gen atoms of the dien backbone. The Re—Nsp2 bond distance, 2.173 (4) Å, is shorter than the Re—Nsp3 bond distances, 2.217 (5) and 2.228 (6) Å, and is similar to the range reported for typical Re—Nsp2 bond lengths (2.14 to 2.18 Å).

The mol­ecular structure of tricarbon­yl[η4-6-exo-(tri­phenyl­phosphino)cyclo­hepta-2,4-dien-1-one]iron(0) tetra­fluoro­borate di­chloro­methane hemisolvate, [Fe(C28H22O4)(CO)3]BF4·0.5CH2Cl2, as determined by single-crystal X-ray diffraction is reported. The two independent tricarbon­yl[η4-6-exo-(tri­phenyl­phosphino)cyclo­hepta-2,4-dien-1-one] iron(0) cations and their corresponding anions form dimers, which constitute the asymmetric unit of the structure parallel to the (100) plane. Solid-state stability within that asymmetric unit as well as between neighboring dimeric units is afforded by C—H⋯O and C—H⋯F hydrogen bonds and C—H⋯π and Y—X⋯π (Y = B, C; X = F, O) inter­actions, which yield diperiodic sheets and a three-dimensional extended network.

The crystal structure of the title 2:1 mol­ecular complex between 2-(allyl­thio)­pyridine and 1,2,4,5-tetra­fluoro-3,6-di­iodo­benzene, C6F4I2·2C8H9NS, at 100 K has been determined in the monoclinic space group P21/c. The most noteworthy characteristic of the complex is the halogen bond between iodine and the pyridine ring with a short N⋯I contact [2.8628 (12) Å]. The Hirshfeld surface analysis shows that the hydrogen⋯hydrogen contacts dominate the crystal packing with a contribution of 32.1%.

The crystal structure of 1,2,3,4-tetra­hydro­isoquinolin-2-ium (2S,3S)-3-carb­oxy-2,3-di­hydroxy­propano­ate monohydrate, C9H12N+·C4H5O6−·H2O, at 115 K shows ortho­rhom­bic symmetry (space group P212121). The hydrogen tartrate anions and solvent water mol­ecules form an intricate diperiodic O—H⋯O hydrogen-bond network parallel to (001). The tetra­hydro­isoquinolinium cations are tethered to the anionic hydrogen-bonded layers through N—H⋯O hydrogen bonds. The crystal packing in the third direction is achieved through van der Waals contacts between the hydro­carbon tails of the tetra­hydro­isoquinolinium cations, resulting in hydro­phobic and hydro­philic regions in the crystal structure.

In the title compound, C19H18BrFN2O, the pyrrolidine ring adopts an envelope conformation. In the crystal, mol­ecules are linked by inter­molecular N—H⋯O, C—H⋯O, C—H⋯F and C—H⋯Br hydrogen bonds, forming a three-dimensional network. In addition, C—H⋯π inter­actions connect mol­ecules into ribbons along the b-axis direction, consolidating the mol­ecular packing. The inter­molecular inter­actions in the crystal structure were qu­anti­fied and analysed using Hirshfeld surface analysis.

The title compound, [Ni(NCS)2(C6H7N)2]n, was prepared by the reaction of Ni(NCS)2 with 4-methyl­pyridine in water. Its asymmetric unit consists of two crystallographically independent NiII cations, of which one is located on a twofold rotational axis whereas the second occupies a center of inversion, two independent thio­cyanate anions and two independent 4-methyl­pyridine co­ligands in general positions. Each NiII cation is octa­hedrally coordinated by two 4-methyl­pyridine coligands as well as two N- and two S-bonded thio­cyanate anions. One of the cations shows an all-trans, the other a cis–cis–trans configuration. The metal centers are linked by pairs of μ-1,3-bridging thio­cyanate anions into [101] chains. X-ray powder diffraction shows that a pure crystalline phase has been obtained and thermogravimetry coupled to differential thermoanalysis reveals that the title compound loses half of the 4-methyl­pyridine coligands and transforms into Ni(NCS)2(C6H7N). Nearly pure samples of this compound can be obtained by thermal annealing and a Rietveld refinement demonstrated that it is isotypic to its recently reported Cd analog [Neumann et al., (2020). CrystEngComm. 22, 184–194] In its crystal structure, the metal cations are linked by one μ-1,3(N,S)- and one μ-1,3,3(N,S,S)-bridging thio­cyanate anion into single chains that condense via the μ-1,3,3(N,S,S)-bridging anionic ligands into double chains.

The pyrazolo­pyrimidine moiety in the title mol­ecule, C13H12N4S, is planar with the methyl­sulfanyl substituent lying essentially in the same plane. The benzyl group is rotated well out of this plane by 73.64 (6)°, giving the mol­ecule an approximate L shape. In the crystal, C—H⋯π(ring) inter­actions and C—H⋯S hydrogen bonds form tubes extending along the a axis. Furthermore, there are π–π inter­actions between parallel phenyl rings with centroid-to-centroid distances of 3.8418 (12) Å. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H⋯H (47.0%), H⋯N/N⋯H (17.6%) and H⋯C/C⋯H (17.0%) inter­actions. The volume of the crystal voids and the percentage of free space were calculated to be 76.45 Å3 and 6.39%, showing that there is no large cavity in the crystal packing. Evaluation of the electrostatic, dispersion and total energy frameworks indicate that the cohesion of the crystal structure is dominated by the dispersion energy contributions.

A new polymorph of the diuretic chloro­thia­zide, 6-chloro-1,1-dioxo-2H-1,2,4-benzo­thia­zine-7-sulfonamide, C7H6ClN3O4S2, is described. Crystallized from basic aqueous solution, this monoclinic polymorph is found to be less thermodynamically favoured than the known triclinic polymorph and to feature only N—H⋯O type inter­molecular hydrogen bonds as opposed to the N—H⋯O and N—H⋯N type hydrogen bonds found in the P1 form.

The compounds 2',3',4',6'-tetra-O-acetyl-β-d-gluco­pyranosyl N'-cyano-N-phenyl­carbamimido­thio­ate (C22H25N3O9S, 5a), 2',3',4',6'-tetra-O-acetyl-β-d-galacto­pyranosyl N'-cyano-N-phenyl­carbamimido­thio­ate, (C22H25N3O9S, 5b), 2',3',4',6'-tetra-O-acetyl-β-d-galacto­pyranosyl N'-cyano-N-methyl­carbamimido­thio­ate (C17H23N3O9S, 5c), and 2',3',4',6'-tetra-O-acetyl-β-d-galacto­pyranosyl N'-cyano-N-p-tolyl­carbamimido­thio­ate (C23H27N3O9S, 5d) all crystallize in P212121 with Z = 4. For all four structures, the configuration across the central (formal) C=N(CN) double bond of the carbamimido­thio­ate group is Z. The torsion angles C5—O1—C1—S (standard sugar numbering) are all close to 180°, confirming the β position of the substituent. Compound 5b involves an intra­molecular hydrogen bond N—H⋯O1; in 5c this contact is the weaker branch of a three-centre inter­action, whereas in 5a and 5d the H⋯O distances are much longer and do not represent significant inter­actions. The C—N bond lengths at the central carbon atom of the carbamimido­thio­ate group are almost equal. All C—O—C=O torsion angles of the acetyl groups correspond to a synperiplanar geometry, but otherwise all four mol­ecules display a high degree of conformational flexibility, with many widely differing torsion angles for equivalent groups. In the crystal packing, 5a, 5c and 5d form layer structures involving the classical hydrogen bond N—H⋯Ncyano and a variety of ‘weak’ hydrogen bonds C—H⋯O or C—H⋯S. The packing of 5b is almost featureless and involves a large number of borderline ‘weak’ hydrogen bonds. In an appendix, a potted history of wavelength preferences for structure determination is presented and it is recommended that, even for small organic crystals in non-centrosymmetric space groups, the use of Mo radiation should be considered.

The X-ray crystal structure data of 12-α-fluoro-3β-hy­droxy­olean-28,13β-olide methanol hemisolvate, 2C30H47FO3·CH3OH, (1), and 12-α-fluoro-3β-hy­droxy­taraxer-28,14β-olide methanol hemisolvate, 2C30H47FO3·CH3OH, (2), are described. The fluoro­lactonization of oleanolic acid using SelectfluorTM yielded a mixture of the six-membered δ-lactone (1) and the unusual seven-membered γ-lactone (2) following a 1,2-shift of methyl C-27 from C-14 to C-13.

The aryl diester compound, 2-methyl-1,4-phenyl­ene bis­(3,5-di­bromo­benzoate), C21H12Br4O4, was synthesized by esterification of methyl hydro­quinone with 3,5-di­bromo­benzoic acid. A crystalline sample was obtained by cooling a sample of the melt (m.p. = 502 K/DSC) to room temperature. The mol­ecular structure consists of a central benzene ring with anti-3,5-di­bromo­benzoate groups symmetrically attached at the 1 and 4 positions and a methyl group attached at the 2 position of the central ring. In the crystal structure (space group Poverline{1}), mol­ecules of the title aryl diester are located on inversion centers imposing disorder of the methyl group and H atom across the central benzene ring. The crystal structure is consolidated by a network of C—H⋯Br hydrogen bonds in addition to weaker and offset π–π inter­actions involving the central benzene rings as well as the rings of the attached 3,5-di­bromo­benzoate groups.

The crystal structures of two inter­mediates, 4-amino-3,5-di­fluoro­benzo­nitrile, C7H4F2N2 (I), and ethyl 4-amino-3,5-di­fluoro­benzoate, C9H9F2NO2 (II), along with a visible-light-responsive azo­benzene derivative, diethyl 4,4'-(diazene-1,2-di­yl)bis­(3,5-di­fluoro­benzoate), C18H14F4N2O4 (III), obtained by four-step synthetic procedure, were studied using single-crystal X-ray diffraction. The mol­ecules of I and II demonstrate the quinoid character of phenyl rings accompanied by the distortion of bond angles related to the presence of fluorine substituents in the 3 and 5 (ortho) positions. In the crystals of I and II, the mol­ecules are connected by N—H⋯N, N—H⋯F and N—H⋯O hydrogen bonds, C—H⋯F short contacts, and π-stacking inter­actions. In crystal of III, only stacking inter­actions between the mol­ecules are found.

The dinuclear mol­ecule of the title compound, [Mo2(C9H13)2(CO)6] or [Mo(tBuCp)(CO)3]2 where tBu and Cp are tert-butyl and cyclo­penta­dienyl, is centrosymmetric and is characterized by an Mo—Mo bond length of 3.2323 (3) Å. Imposed by inversion symmetry, the tBuCp and the carbonyl ligands are in a transoid arrangement to each other. In the crystal, inter­molecular C—H⋯O contacts lead to the formation of layers parallel to the bc plane.

The di­hydro­imidazole ring in the title mol­ecule, C20H20N2O3S, is slightly distorted and the lone pair on the tri-coordinate nitro­gen atom is involved in intra-ring π bonding. The methyl­sulfanyl substituent lies nearly in the plane of the five-membered ring while the ester substituent is rotated well out of that plane. In the crystal, C—H⋯O hydrogen bonds form inversion dimers, which are connected along the a- and c-axis directions by additional C—H⋯O hydrogen bonds, forming layers parallel to the ac plane. The major contributors to the Hirshfeld surface are C⋯H/H⋯C, O⋯H/H⋯O and S⋯H/H⋯S contacts at 20.5%, 14.7% and 4.9%, respectively.

The title compound, C17H13BrN4O5, was synthesized by a Cu2Br2-catalysed Meldal–Sharpless reaction between 4-nitro­phen­oxy­acetic acid propargyl ether and para-bromo­phenyl­azide, and characterized by X-ray structure determination and 1H NMR spectroscopy. The mol­ecules, with a near-perpendicular orientation of the bromo­phenyl-triazole and nitro­phen­oxy­acetate fragments, are connected into a three-dimensional network by inter­molecular C—H⋯O and C—H⋯N hydrogen bonds (confirmed by Hirshfeld surface analysis), π–π and Br–π inter­actions.

The crystal structure of hexa­glycinium tetra-μ-iodido-octa­iodido­triplumbate, (C2H6NO2)6[Pb3I12] or (GlyH)6[Pb3I12], is reported. The compound crystallizes in the triclinic space group Poverline{1}. The [Pb3I12]6− anion is discrete and located around a special position: the central Pb ion located on the inversion center is holodirected, while the other two are hemidirected. The supra­molecular nature is mainly based on C—H⋯I, N—H⋯I, O—H⋯I and N—H⋯O hydrogen bonds. Dimeric cations of type (A+⋯A+) for the amino acid glycine are observed for the first time.

In the title mol­ecule, C25H29N5O, the di­hydro­quinoxaline unit is not quite planar (r.m.s. deviation = 0.030 Å) as there is a dihedral angle of 2.69 (3)° between the mean planes of the constituent rings and the mol­ecule adopts a hairpin conformation. In the crystal, the polar portions of the mol­ecules are associated through C—H⋯O and C—H⋯N hydrogen bonds and C—H⋯π(ring) and C=O⋯π(ring) inter­actions, forming thick layers parallel to the bc plane and with the n-octyl groups on the outside surfaces.

This study presents the synthesis, characterization and Hirshfeld surface analysis of the title mononuclear complex, [PdCl2(C12H14N4)]·C3H7NO. The compound crystalizes in the P21/c space group of the monoclinic system. The asymmetric unit contains one neutral complex Pd(HLc-Pe)Cl2 [HLc-Pe is 2-(3-cyclo­pentyl-1,2,4-triazol-5-yl)pyridine] and one mol­ecule of DMF as a solvate. The Pd atom has a square-planar coordination. In the crystal, mol­ecules are linked by inter­molecular N—H⋯O and C—H⋯N hydrogen bonds, forming layers parallel to the bc plane. A Hirshfeld surface analysis showed that the H⋯H contacts dominate the crystal packing with a contribution of 41.4%. The contribution of the N⋯H/H⋯N and H⋯O/O⋯H inter­actions is somewhat smaller, amounting to 12.4% and 5%, respectively.

This study presents the synthesis, characterization and Hirshfeld surface analysis of 1-[6-bromo-2-(3-bromo­phen­yl)-1,2,3,4-tetra­hydro­quinolin-4-yl]pyrrolidin-2-one, C19H18Br2N2O. In the title compound, the pyrrolidine ring adopts a distorted envelope configuration. In the crystal, mol­ecules are linked by inter­molecular N—H⋯O, C—H⋯O and C—H⋯Br hydrogen bonds, forming a three-dimensional network. In addition, pairs of mol­ecules along the c axis are connected by C—H⋯π inter­actions. According to a Hirshfeld surface study, H⋯H (36.9%), Br⋯H/H⋯Br (28.2%) and C⋯H/H⋯C (24.3%) inter­actions are the most significant contributors to the crystal packing.

In the title compound, C33H29ClN2O2, the two piperidine rings of the di­aza­bicyclo moiety adopt distorted-chair conformations. Inter­molecular C—H⋯π inter­actions are mainly responsible for the crystal packing. The inter­molecular inter­actions were qu­anti­fied and analysed using Hirshfeld surface analysis, revealing that H⋯H inter­actions contribute most to the crystal packing (52.3%). The mol­ecular structure was further optimized by density functional theory (DFT) at the B3LYP/6–31 G(d,p) level and is compared with the experimentally determined mol­ecular structure in the solid state.

In the structure of the title salt, {[Ba(μ3-C3H2N3O2)2(μ-H2O)(H2O)]·H2O}n, the barium ion and all three oxygen atoms of the water mol­ecules reside on a mirror plane. The hydrogen atoms of the bridging water and the solvate water mol­ecules are arranged across a mirror plane whereas all atoms of the monodentate aqua ligand are situated on this mirror plane. The distorted ninefold coord­ination of the Ba ions is completed with four nitroso-, two carbonyl- and three aqua-O atoms at the distances of 2.763 (3)–2.961 (4) Å and it is best described as tricapped trigonal prism. The three-dimensional framework structure is formed by face-sharing of the trigonal prisms, via μ-nitroso- and μ-aqua-O atoms, and also by the bridging coordination of the anions via carbonyl-O atoms occupying two out of the three cap positions. The solvate water mol­ecules populate the crystal channels and facilitate a set of four directional hydrogen bonds. The principal Ba–carbamoyl­cyano­nitro­somethanido linkage reveals a rare example of the inherently polar binodal six- and three-coordinated bipartite topology (three-letter notation sit). It suggests that small resonance-stabilized cyano­nitroso anions can be utilized as bridging ligands for the supra­molecular synthesis of MOF solids. Such an outcome may be anti­cipated for a broader range of hard Lewis acidic alkaline earth metal ions, which perfectly match the coordination preferences of highly nucleophilic nitroso-O atoms. Thermal analysis reveals two-stage dehydration of the title compound (383 and 473 K) followed by decomposition with release of CO2, HCN and H2O at 558 K.

The mol­ecular structure of the tripodal carbamoyl­methyl­phosphine oxide compound diethyl {[(5-[2-(di­eth­oxy­phosphor­yl)acetamido]-3-{2-[2-(di­eth­oxy­phos­phor­yl)acetamido]­eth­yl}pent­yl)carbamo­yl]meth­yl}phospho­nate, C25H52N3O12P3, features six intra­molecular hydrogen-bonding inter­actions. The phospho­nate groups have key bond lengths ranging from 1.4696 (12) to 1.4729 (12) Å (P=O), 1.5681 (11) to 1.5811 (12) Å (P—O) and 1.7881 (16) to 1.7936 (16) Å (P—C). Each amide group adopts a nearly perfect trans geometry, and the geometry around each phophorus atom resembles a slightly distorted tetra­hedron.

The two mol­ecules in the asymmetric unit of the title compound, C23H24N2O2S, have a structural overlap with an r.m.s. deviation of 0.82 Å. The piperidine rings adopt a distorted boat conformation. Intra- and inter­molecular C—H⋯O hydrogen bonds are responsible for the cohesion of the crystal packing. The inter­molecular inter­actions were qu­anti­fied and analysed using Hirshfeld surface analysis. The mol­ecular structure optimized by density functional theory (DFT) at the B3LYP/6–311++G(d,p)level is compared with the experimentally determined mol­ecular structure in the solid state.

Coordination compounds of polydentate nitro­gen ligands with metals are used extensively in research areas such as catalysis, and as models of complex active sites of enzymes in bioinorganic chemistry. Tris(2-pyridyl­meth­yl)amine (TPA) is a tripodal tetra­dentate ligand that is known to form coordination compounds with metals, including copper, iron and zinc. The related compound, tris­[(6-bromo­pyridin-2-yl)meth­yl]amine (TPABr3), C18H15Br3N4, which possesses a bromine atom on the 6-position of each of the three pyridyl moieties, is also known but has not been heavily investigated. The mol­ecular structure of TPABr3 as determined by X-ray diffraction is reported here. The TPABr3 molecule belongs to the triclinic, Poverline{1} space group and displays interesting intermolecular Br⋯Br interactions that provide a stabilizing influence within the molecule.

This work describes the X-ray structure of orange–red crystals of 2-meth­oxy-5-nitro­aniline, C7H8N2O3. The compound displays concentration-dependent UV-Vis spectra, which is attributed to dipole-induced aggregation, and light absorption arising from an inter­molecular charge-transfer process that decreases in energy as the degree of aggregation increases. The crystals display π-stacking where the dipole moments align anti­parallel. Stacked mol­ecules inter­act with the next stack via hydrogen bonds, which is a state of maximum aggregation. Light absorption by charge transfer can be compared to colored inorganic semiconductors such as orange–red CdS, with a band gap of 2.0–2.5 eV.