The (S)-(+)-1-(4-bromo­phen­yl)-N-[(4-methoxyphen­yl)methyl­idene]ethyl­amine ligand, C16H16BrNO, (I), was synthesized through the reaction of 4-meth­oxy­anisaldehyde with (S)-(−)-1-(4-bromo­phen­yl)ethyl­amine. It crystallizes in the ortho­rhom­bic space group P212121 belonging to the Sohncke group, featuring a single mol­ecule in the asymmetric unit. The refinement converged successfully, achieving an R factor of 0.0508. The PdII com­plex bis­{(S)-(+)-1-(4-bromo­phen­yl)-N-[(4-methoxyphen­yl)methyl­idene]ethyl­amine-κN}di­chlorido­pal­ladium(II), [PdCl2(C16H16BrNO)2], (II), crystallizes in the monoclinic space group P21 belonging to the Sohncke group, with two mol­ecules in the asymmetric unit. The central atom is tetra­coordinated by two N atoms and two Cl atoms, resulting in a square-planar configuration. The imine moieties exhibit a trans configuration around the PdII centre, with average Cl—Pd—N angles of approximately 89.95 and 90°. The average distances within the palladium com­plex for the two mol­ecules are ∼2.031 Å for Pd—N and ∼2.309 Å for Pd—Cl.

A new lanthanide coordination polymer, poly[[tri­aqua­bis­(μ4-phthalato)(μ3-pyridine-2,5-di­carboxyl­ato)dipraseodymium] monohydrate], {[Pr2(C7H3NO4)2(C8H4O4)(H2O)3]·H2O}n or {[Pr2(phth)2(pydc)(H2O)3]·H2O}n, (pydc2− = pyridine-2,5-di­carboxyl­ate and phth2− = phthalate) was synthesized and characterized, revealing the structure to be an assembly of di-periodic {Pr2(pydc)(phth)2(H2O)3}n layers. Each layer is built up by edge-sharing {Pr2N2O14} and {Pr2O16} dimers, which are connected through a new coordin­ation mode of pydc2− and phth2−. These layers are stabilized by inter­nal hydrogen bonds and π–π inter­actions. In addition, a three-dimensional supra­molecular framework is built by inter­layer hydrogen-bonding inter­actions involving the non-coordinated water mol­ecule. Thermogravimetric analysis shows that the title compound is thermally stable up to 400°C.

The title compound [systematic name: 1-(2-nitro­phen­yl)pyrrole-2,5-dione], C10H6N2O4, crystallizes in the monoclinic system (space group P21/n) with two mol­ecules in the asymmetric unit, which are linked by C—H⋯O hydrogen bonds. Hirshfeld surface analysis showed that the most significant contributions to the crystal packing are from H⋯O/O⋯H, H⋯C/C⋯H and H⋯H inter­actions, which contribute 54.7%, 15.2% and 15.6%, respectively. A DFT study was conducted using three different levels of theory [(B3LYP/6–311+G(d,p), wB97XD/Def2TZVPP and LC-wpbe/6–311(2 d,2p)] in order to determine the stability, structural and electronic properties of the title mol­ecule with a view to its potential applications and photochemical and copolymer properties.

The reaction between 2-pyridyl­selenenyl chloride and isobutyro­nitrile results in the formation of the corresponding cationic pyridinium-fused 1,2,4-seleno­diazole, namely, 3-(propan-2-yl)-1,2,4-[1,2,4]selena­diazolo[4,5-a]pyridin-4-ylium chloride, C9H11N2Se+·Cl−, in high yield (89%). The structure of the compound, established by means of single-crystal X-ray analysis at 100 K, has monoclinic (P21/c) symmetry and revealed the presence of bifurcated chalcogen-hydrogen bonding Se⋯Cl−⋯H—Cl, and these non-covalent contacts were analysed by DFT calculations followed by a topological analysis of the electron-density distribution (ωB97XD/6-311++G** level of theory).

The title mol­ecule, [Fe2(C5H5)2(C23H17ClN2)]·C3H7NO, is twisted end to end and the central N/C/N unit is disordered. In the crystal, several C—H⋯π(ring) inter­actions lead to the formation of layers, which are connected by further C—H⋯π(ring) inter­actions. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (60.2%) and H⋯C/C⋯H (27.0%) inter­actions. Hydrogen bonding, C—H⋯π(ring) inter­actions and van der Waals inter­actions dominate the crystal packing.

Two compounds, (S)-8-{[(tert-butyl­dimethyl­sil­yl)­oxy]meth­yl}-1-[(2,2,4,6,7-penta­methyl-2,3-di­hydro­benzo­furan-5-yl)sulfon­yl]-1,3,4,6,7,8-hexa­hydro-2H-pyrimido[1,2-a]pyrimidin-1-ium tri­fluoro­methane­sulfonate, C27H46N3O4SSi+·CF3O3S−, (1) and (S)-8-(iodo­meth­yl)-1-tosyl-1,3,4,6,7,8-hexa­hydro-2H-pyrimido[1,2-a]pyrimidin-1-ium iodide, C15H21IN3O2S+·I−, (2), have been synthesized and characterized. They are bicyclic guanidinium salts and were synthesized from N-(tert-but­oxy­carbon­yl)-l-me­thio­nine (Boc-l-Met-OH). The guanidine is protected by a 2,2,4,6,7-penta­methyl­dihydro­benzo­furan-5-sulfonyl (Pbf, 1) or a tosyl (2) group. In the crystals of both compounds, the guanidinium group is almost planar and the N–H forms an intra­molecular hydrogen bond in a six-membered ring to the oxygen atom of the sulfonamide protecting group.

The crystal structure of the tetra­ethyl­ammonium salt of the non-steroidal anti-inflammatory drug nimesulide (polymorph II) (systematic name: tetra­ethyl­ammonium N-methane­sulfonyl-4-nitro-2-phen­oxy­anilinide), C8H20N+·C13H11N2O5S−, was determined using single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic space group P21/c with one tetra­ethyl­ammonium cation and one nimesulide anion in the asymmetric unit. In the crystal, the ions are linked by C—H⋯N and C—H⋯O hydrogen bonds and C—H⋯π inter­actions. There are differences in the geometry of both the nimesulide anion and the tetra­ethyl­ammonium cation in polymorphs I [Rybczyńska & Sikorski (2023). Sci. Rep. 13, 17268] and II of the title compound.

The crystal structure of the title compound {systematic name: (4S,4aS,5aR,12aR)-4,7-bis­(di­methyl­amino)-9-[(2,2-di­methyl­propyl­amino)­meth­yl]-1,10,11,12a-tetra­hydroxy-3,12-dioxo-4a,5,5a,6-tetra­hydro-4H-tetra­cene-2-carb­oxamide dihydrate, C29H40N4O7·2H2O} has been solved and refined using synchrotron X-ray powder diffraction data: it crystallizes in space group R3 with a = 24.34430 (7), c = 14.55212 (4) Å, V = 7468.81 (2) Å3 and Z = 9. Most of the hydrogen bonds are intra­molecular, but two classical N—H⋯O inter­molecular hydrogen bonds (along with probable weak C—H⋯O and C—H⋯N hydrogen bonds) link the mol­ecules into a three-dimensional framework. The framework contains voids, which contain disordered water mol­ecules. Keto–enol tautomerism is apparently important in this mol­ecule, and the exact mol­ecular structure is ambiguous.

The crystal structure of the sodium salt of mesotrione, namely, catena-poly[[sodium-μ3-2-[(4-methane­sulfonyl-2-nitro­phen­yl)carbon­yl]-3-oxo­cyclo­hex-1-en-1-olato] ethanol monosolvate], {[Na(C14H12NO7S)]C2H5OH}n, is described. The X-ray structural analysis results reveal that the coordination sphere is established by two chelating O atoms, the O atom of the coordinated ethanol mol­ecule, and an O atom from the methyl­sulfonyl group of a neighboring mol­ecule. Simultaneously, an O atom of the cyclo­hexane fragment serves as a bridge to a neighboring sodium ion, forming a flat Na–O–Na–O quadrangle, thereby forming a mono-periodic polymer. The structure displays O—H⋯O hydrogen bonds and C—H⋯O short contacts. Thermogravimetric analysis (TGA) data indicate that the sodium salt of mesotrione decomposes in four stages.

An attempt to explore the reactivity of the nitro group in the presence of gold catalysis in comparison to the azide group yielded intriguing results. Surprisingly, only the nitro group exhibited reactivity, ultimately giving rise to the formation of the title isatogen, C14H8N4O2. In the crystal structure, weak C—H⋯O hydrogen bonds and π–π stacking inter­actions link the mol­ecules. The structure exhibits disorder of the mol­ecule.

The title compound, C14H12N2O4, was obtained from 2-acetyl-6-amino­naphthalene through two-step reactions of acetyl­ation and nitration. The mol­ecule comprises the naphthalene ring system consisting of functional systems bearing a acetyl group (C-2), a nitro group (C-5), and an acetyl­amino group (C-6). In the crystal, the mol­ecules are assembled into two-dimensional sheet-like structures by inter­molecular N—H⋯O and C—H⋯O hydrogen-bonding inter­actions. Hirshfeld surface analysis illustrates that the most important contributions to the crystal packing are from O⋯H/H⋯O (43.7%), H⋯H (31.0%), and C⋯H/H⋯C (8.5%) contacts.

In the title compound, C21H15N5OS2, mol­ecular pairs are linked by N—H⋯N hydrogen bonds along the c-axis direction and C—H⋯S and C—H⋯O hydrogen bonds along the b-axis direction, with R22(12) and R22(16) motifs, respectively, thus forming layers parallel to the (10overline{4}) plane. In addition, C=S⋯π and C≡N⋯π inter­actions between the layers ensure crystal cohesion. The Hirshfeld surface analysis indicates that the major contributions to the crystal packing are H⋯H (43.0%), C⋯H/H⋯C (16.9%), N⋯H/H⋯N (11.3%) and S⋯H/H⋯S (10.9%) inter­actions.

Metal complexes of 3,5-diiso­propyl­salicylate are reported to have anti-inflammatory and anti-convulsant activities. The title binuclear copper complex, [Cu2(C13H17O3)4(C2H6OS)2] or [Cu(II)2(3,5-DIPS)4(DMSO)2], contains two five-coordinate copper atoms that are bridged by four 3,5-diiso­propyl­salicylate ligands and capped by two axial dimethyl sulfoxide (DMSO) moieties. Each copper atom is attached to four oxygen atoms in an almost square-planar fashion, with the addition of a DMSO ligand in an apical position leading to a square-pyramidal arrangement. The hy­droxy group of the diiso­propyl­salicylate ligands participates in intra­molecular O—H⋯O hydrogen-bonding inter­actions.

The complex, tri­chlorido­(1,4,11-tri­aza-8-azonia­tetra­cyclo­[6.6.2.04,16.011,15]hexa­decane 1-oxide-κO)zinc(II) monohydrate, [ZnCl3(C12H23N4O)]·H2O, (I), has monoclinic symmetry (space group P21/n) at 120 K. The zinc(II) center adopts a slightly distorted tetra­hedral coordination geometry and is coordinated by three chlorine atoms and the oxygen atom of the oxidized tertiary amine of the tetra­cycle. The amine nitro­gen atom, inside the ligand cleft, is protonated and forms a hydrogen bond to the oxygen of the amine oxide. Additional hydrogen-bonding inter­actions involve the protonated amine, the water solvate oxygen atom, and one of the chloro ligands.

The structures of ten phosphane chalcogenide complexes of gold(III) halides, with general formula R13–nR2nPEAuX3 (R1 = t-butyl; R2 = i-propyl; n = 0 to 3; E = S or Se; X = Cl or Br) are presented. The eight possible chlorido derivatives are: 9a, n = 3, E = S; 10a, n = 2, E = S; 11a, n = 1, E = S; 12a, n = 0, E = S; 13a, n = 3, E = Se; 14a, n = 2, E = Se; 15a, n = 1, E = Se; and 16a, n = 0, E = Se, and the corresponding bromido derivatives are 9b–16b in the same order. Structures were obtained for 9a, 10a (and a second polymorph 10aa), 11a (and its deutero­chloro­form monosolvate 11aa), 12a (as its di­chloro­methane monosolvate), 14a, 15a (as its deutero­chloro­form monosolvate 15aa, in which the solvent mol­ecule is disordered over two positions), 9b, 11b, 13b and 15b. The structures of 11a, 15a, 11b and 15b form an isotypic set, and those of compounds 10aa and 14a form an isotypic pair. All structures have Z' = 1. The gold(III) centres show square-planar coordination geometry and the chalcogenide atoms show approximately tetra­hedral angles (except for the very wide angle in 12a, probably associated with the bulky t-butyl groups). The bond lengths at the gold atoms are lengthened with respect to the known gold(I) derivatives, and demonstrate a considerable trans influence of S and Se donor atoms on a trans Au—Cl bond. Each compound with an isopropyl group shows a short intra­molecular contact of the type C—Hmethine⋯Xcis; these may be regarded as intra­molecular ‘weak’ hydrogen bonds, and they determine the orientation of the AuX3 groups. The mol­ecular packing is analysed in terms of various short contacts such as weak hydrogen bonds C—H⋯X and contacts between the heavier atoms, such as X⋯X (9a, 10aa, 11aa, 15aa and 9b), S⋯S (10aa, 11a and 12a) and S⋯Cl (10a). The packing of the polymorphs 10a and 10aa is thus quite different. The solvent mol­ecules take part in C—H⋯Cl hydrogen bonds; for 15aa, a disordered solvent region at z ≃ 0 is observed. Structure 13b involves unusual inversion-symmetric dimers with Se⋯Au and Se⋯Br contacts, further connected by Br⋯Br contacts.

The title compound, C14H12N4O2·0.5HCl·H2O or H(C14H12N4O2)2+·Cl−·2H2O, arose from the unexpected cyclization of isonicotinoyl-N-phenyl hydrazine carbo­thio­amide catalysed by cobalt(II) acetate. The organic mol­ecule is almost planar and a symmetric N⋯H+⋯N hydrogen bond links two of them together, with the H atom lying on a crystallographic twofold axis. The extended structure features N—H⋯O and O—H⋯Cl hydrogen bonds, which generate [001] chains. Weak C—H⋯Cl inter­actions cross-link the chains. The chloride ion has site symmetry 2. The major contributions to the Hirshfeld surface are from H⋯H (47.1%), Cl⋯H/H⋯Cl (total 10.8%), O⋯H/H⋯O (7.4%) and N⋯H/H⋯N (6.7%) inter­actions.

The asymmetric unit of the title compound, 2C31H28N2O4S·C2H6O, contains a parent mol­ecule and a half mol­ecule of ethanol solvent. The main compound stabilizes its mol­ecular conformation by forming a ring with an R12(7) motif with the ethanol solvent mol­ecule. In the crystal, mol­ecules are connected by C—H⋯O and O—H⋯O hydrogen bonds, forming a three-dimensional network. In addition, C—H⋯π inter­actions also strengthen the mol­ecular packing.

In the title mol­ecule, C21H23N3O3, the imidazolidine ring slightly deviates from planarity and the morpholine ring exhibits the chair conformation. In the crystal, N—H⋯O and C—H⋯O hydrogen bonds form helical chains of mol­ecules extending parallel to the c axis that are connected by C—H⋯π(ring) inter­actions. A Hirshfeld surface analysis reveals that the most important contributions for the crystal packing are from H⋯H (55.2%), H⋯C/C⋯H (22.6%) and H⋯O/O⋯H (20.5%) inter­actions. The volume of the crystal voids and the percentage of free space were calculated to be 236.78 Å3 and 12.71%, respectively. Evaluation of the electrostatic, dispersion and total energy frameworks indicates that the stabilization is dominated by the nearly equal electrostatic and dispersion energy contributions. The DFT-optimized mol­ecular structure at the B3LYP/6-311 G(d,p) level is compared with the experimentally determined mol­ecular structure in the solid state. Moreover, the HOMO–LUMO behaviour was elucidated to determine the energy gap.

N-Phenyl-2-(phenyl­sulfan­yl)acetamide, C14H13NOS, was synthesized and structurally characterized. In the crystal, N—H⋯O hydrogen bonding leads to the formation of chains of mol­ecules along the [100] direction. The chains are linked by C—H⋯π inter­actions, forming a three-dimensional network. The crystal studied was twinned by a twofold rotation around [100].

In the structure of the title compound, C22H22N4O4·C3H7NO·H2O, the entire tricyclic system is approximately planar except for the carbon atom bearing the two methyl groups; the meth­oxy­phenyl ring is approximately perpendicular to the tricycle. All seven potential hydrogen-bond donors take part in classical hydrogen bonds. The main mol­ecule and the DMF combine to form broad ribbons parallel to the a axis and roughly parallel to the ab plane; the water mol­ecules connect the residues in the third dimension.

A novel cationic complex, bromido­tetra­kis­[5-(prop-2-en-1-ylsulfan­yl)-1,3,4-thia­diazol-2-amine-κN3]copper(II) bromide, [CuBr](C5H7N3S2)4Br, was synthesized. The complex crystallizes with fourfold mol­ecular symmetry in the tetra­gonal space group P4/n. The CuII atom exhibits a square-pyramidal coord­ination geometry. The Cu atom is located centrally within the complex, being coordinated by four nitro­gen atoms from four AAT mol­ecules, while a bromine anion is located at the apex of the pyramid. The amino H atoms of AAT inter­act with bromine from the inner and outer spheres, forming a two-dimensional network in the [100] and [010] directions. Hirshfeld surface analysis reveals that 33.7% of the inter­mol­ecular inter­actions are from H⋯H contacts, 21.2% are from S⋯H/H⋯S contacts, 13.4% are from S⋯S contacts and 11.0% are from C⋯H/H⋯C, while other contributions are from Br⋯H/H⋯Br and N⋯H/H⋯N contacts.

In the structure of the title co-crystal, C3H3N3O2·C5H8N2, the components are linked by a set of directional O—H⋯N, N—H⋯O, N—H⋯N and C—H⋯O hydrogen bonds to yield a two-dimensional mono-periodic arrangement. The structure propagates in the third dimension by extensive π–π stacking inter­actions of nearly parallel mol­ecules of the two components, following an alternating sequence. The primary structure-defining inter­action is very strong oxime-OH donor to pyrazole-N acceptor hydrogen bond [O⋯N = 2.587 (2) Å], while the significance of weaker hydrogen bonds and π–π stacking inter­actions is comparable. The distinct structural roles of different kinds of inter­actions agree with the results of a Hirshfeld surface analysis and calculated inter­action energies. The title compound provides insights into co-crystals of active agrochemical mol­ecules and features the rational integration in one structure of a fungicide, C3H3N3O2, and a second active component, C5H8N2, known for alleviation the toxic effects of fungicides on plants. The material appears to be well suited for practical uses, being non-volatile, air-stable, water-soluble, but neither hygroscopic nor efflorescent.

Carb­oxy­hydrazides are widely used in medicinal chemistry because of their medicinal properties and many drugs have been developed containing this functional group. A suitable inter­mediate to obtain potential hydrazide drug candidates is the title compound 5-hy­droxy­penta­nehydrazide, C5H12N2O2 (1). The aliphatic compound can react both via the hydroxyl and hydrazide moieties forming derivatives, which can inhibit Mycobacterium tuberculosis catalase-peroxidase (KatG) and consequently causes death of the pathogen. In this work, the hydrazide was obtained via a reaction of a lactone with hydrazine hydrate. The colourless prismatic single crystals belong to the ortho­rhom­bic space group Pca21. Regarding supra­molecular inter­actions, the compound shows classic medium to strong inter­molecular hydrogen bonds involving the hydroxyl and hydrazide groups. Besides, the three-dimensional packing also shows weak H⋯H and C⋯H contacts, as investigated by Hirshfeld surface analysis (HS) and fingerprint plots (FP).

The title compound (C14H23N3S, common name: cis-jasmone 4-ethyl­thio­semicarbazone) was synthesized by the equimolar reaction of cis-jasmone and 4-ethyl­thio­semicarbazide in ethanol facilitated by acid catalysis. There is one crystallographically independent mol­ecule in the asymmetric unit, which shows disorder of the terminal ethyl group of the jasmone carbon chain [site-occupancy ratio = 0.911 (5):0.089 (5)]. The thio­semicarbazone entity [N—N—C(=S)—N] is approximately planar, with the maximum deviation of the mean plane through the N/N/C/S/N atoms being 0.0331 (8) Å, while the maximum deviation of the mean plane through the five-membered ring of the jasmone fragment amounts to −0.0337 (8) Å. The dihedral angle between the two planes is 4.98 (7)°. The mol­ecule is not planar due to this structural feature and the sp3-hybridized atoms of the jasmone carbon chain. Additionally, one H⋯N intra­molecular inter­action is observed, with graph-set motif S(5). In the crystal, the mol­ecules are connected through pairs of H⋯S inter­actions with R22(8) and R21(7) graph-set motifs into centrosymmetric dimers. The dimers are further connected by H⋯N inter­actions with graph-set motif R22(12), which are related by an inversion centre, forming a mono-periodic hydrogen-bonded ribbon parallel to the b-axis. The crystal structure and the supra­molecular assembly of the title compound are compared with four known cis-jasmone thio­semicarbazone derivatives (two crystalline modifications of the non-substituted form, the 4-methyl and the 4-phenyl derivatives). A Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are from H⋯H (70.7%), H⋯S/S⋯H (13.5%), H⋯C/C⋯H (8.8%), and H⋯N/N⋯H (6.6%) inter­faces (only the disordered atoms with the highest s.o.f. were considered for the evaluation).

The title compound, [Mo3(C9H18NS2)3(S2)3S]2S, crystallizes on a general position in the monoclinic space group P21/n (No. 14). The cationic [Mo3S7(S2CNiBu2)3]+ fragments are joined by a mono­sulfide dianion that forms close S⋯S contacts to each of the di­sulfide ligands on the side of the Mo3 plane opposite the μ32− ligand. The two Mo3 planes are inclined at an angle of 40.637 (15)°, which gives the assembly an open clamshell-like appearance. One μ6-S2−⋯S22− contact, at 2.4849 (14) Å, is appreciably shorter than the remaining five, which are in the range 2.7252 (13)–2.8077 (14) Å.

The title copper(II) complex, [Cu(C18H19N3O3)(C3H4N2)], consists of a tridentate ligand synthesized from l-leucine and azo­benzene-salicyl­aldehyde. One imidazole mol­ecule is additionally coordinated to the copper(II) ion in the equatorial plane. The crystal structure features N—H⋯O hydrogen bonds. A Hirshfeld surface analysis indicates that the most important contributions to the packing are from H⋯H (52.0%) and C⋯H/H⋯C (17.9%) contacts.

Reaction of Co(NCS)2 with 2-methyl­pyridine N-oxide in a 1:3 ratio in n-butanol leads to the formation of crystals of tris­(2-methyl­pyridine N-oxide-κO)bis­(thio­cyanato-κN)cobalt(II), [Co(NCS)2(C6H7NO)3]. The asymmetric unit of the title compound consists of one CoII cation two thio­cyanate anions and three crystallographically independent 2-methyl­pyridine N-oxide coligands in general positions. The CoII cations are trigonal–bipyramidally coordinated by two terminal N-bonding thio­cyanate anions in the trans-positions and three 2-methyl­pyridine N-oxide coligands into discrete complexes. These complexes are linked by inter­molecular C–H⋯S inter­actions into double chains that elongate in the c-axis direction. Powder X-ray diffraction (PXRD) measurements prove that all batches are always contaminated with an additional and unknown crystalline phase. Thermogravimetry and differential analysis of crystals selected by hand reveal that the title compound decomposes at about 229°C in an exothermic reaction. At about 113°C a small endothermic signal is observed that, according to differential scanning calorimetry (DSC) measurements, is irreversible. PXRD measurements of the residue prove that a poorly crystalline and unknown phase has formed and thermomicroscopy indicates that some phase transition occurs that is accompanied with a color change of the title compound.

The structure of the title compound, C23H21BrN4O, contains two independent mol­ecules connected by hydrogen bonds of the type Namide—H⋯N≡C to form a dimer. The configuration at the exocyclic C=C double bond is E. The mol­ecules are roughly planar except for the isopropyl groups. There are minor differences in the orientations of these groups and the phenyl rings at N1. The dimers are further linked by ‘weak’ hydrogen bonds, two each of the types Hphen­yl⋯O=C (H⋯O = 2.50, 2.51 Å) and Hphen­yl⋯Br (H⋯Br = 2.89, 2.91 Å), to form ribbons parallel to the b and c axes, respectively. The studied crystal was a non-merohedral twin.

Reaction of Co(NCS)2 with 4-methyl­pyridine N-oxide in methanol leads to the formation of crystals of the title compound, [Co2(NCS)4(C6H7NO)4(CH4O)2] or Co2(NCS)4(4-methyl­pyridine N-oxide)4(methanol)2. The asymmetric unit consist of one CoII cation, two thio­cyanate anions, two 4-methyl­pyridine N-oxide coligands and one methanol mol­ecule in general positions. The H atoms of one of the methyl groups are disordered and were refined using a split model. The CoII cations octa­hedrally coordinate two terminal N-bonded thio­cyanate anions, three 4-methyl­pyridine N-oxide coligands and one methanol mol­ecule. Each two CoII cations are linked by pairs of μ-1,1(O,O)-bridging 4-methyl­pyridine N-oxide coligands into dinuclear units that are located on centers of inversion. Powder X-ray diffraction (PXRD) investigations prove that the title compound is contaminated with a small amount of Co(NCS)2(4-meth­yl­pyridine N-oxide)3. Thermogravimetric investigations reveal that the methanol mol­ecules are removed in the beginning, leading to a compound with the composition Co(NCS)2(4-methyl­pyridine N-oxide), which has been reported in the literature and which is of poor crystallinity.

Di-μ-hydroxido-bis­[di­bromido­(di­methyl­formamide-κO)ethyl­tin(IV)], [Sn2Br4(C2H5)2(OH)2(C3H7NO)2], was prepared from ethyl­tin(IV) bromide and N,N-di­methyl­formamide (DMF) in air. The crystal structure exhibits the typical structural features of dimeric Lewis-base-stabilized monoorganotin(IV)–dihalide–hydroxides, RSnHal2(OH), i.e. two octa­hedrally coordinated Sn atoms are linked together via two bridging hydroxide groups, resulting in a centrosymmetric four-membered rhomboid-like Sn–OH ring with acute angles at the Sn atom, obtuse angles at the O atoms and two different tin–oxygen bond lengths. With the shorter bond trans to the ethyl group, this observation underlines once more the so-called trans-strengthening effect in monoorganotin(IV) com­pounds with octa­hedrally coordinated Sn atoms. Differences and similarities in the bond lengths and angles in the four-membered Sn–OH rings have been worked out for the rings in dimeric diorganotin(IV)–halide–hydroxides, [R2SnHal(OH)]2, and hydrates of dimeric tin(IV)–trihalide–hydroxide–aqua–hydrates, [SnHal3(OH)(H2O)]2·nH2O.

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.

4,4'-(Disulfanedi­yl)dipyridinium chloride triiodide, C10H10N2S22+·Cl−·I3−, (1) was synthesized by reaction of 4,4'-di­pyridyl­disulfide with ICl in a 1:1 molar ratio in di­chloro­methane solution. The structural characterization of 1 by SC-XRD analysis was supported by elemental analysis, FT–IR, and FT–Raman spectroscopic measurements.

The title coordination polymer with the 4-methyl-N-(pyridin-2-yl­methyl­idene)aniline Schiff base ligand (L, C13H12N2), [Cd2Cl4(C13H12N2)]n (1), exhibits a columnar structure extending parallel to [100]. The columns are aligned in parallel and are decorated with chelating L ligands on both sides. They are elongated into a supra­molecular sheet extending parallel to (01overline{1}) through π–π stacking inter­actions involving L ligands of neighbouring columns. Adjacent sheets are packed into the tri-periodic supra­molecular network through weak C—H⋯Cl hydrogen-bonding inter­actions that involve the phenyl CH groups and chlorido ligands. The thermal stability and photoluminescent properties of (1) have also been examined.

The reaction of copper(II) oxalate and hexa­methyl­ene­tetra­mine in a deep eutectic solvent made of urea and choline chloride produced crystals of penta­amine­copper(II) dichloride–urea (1/1), [Cu(NH3)5]Cl2·CO(NH2)2, which was characterized by single-crystal X-ray diffraction. The complex contains discrete penta­amine­copper(II) units in a square-based pyramidal geometry. The overall structure of the multi-component crystal is dictated by hydrogen bonding between urea mol­ecules and amine H atoms with chloride anions.

The reaction of lithium hexa­methyl­disilyl­amide, [Li{N(Si(CH3)3)2}] (LiHMDS), with 4,4-dimethyl-2-phenyl-2-oxazoline (Phox, C11H13NO) in hexane produced colourless crystals of bis­(4,4-dimethyl-2-phenyl-2-oxazoline-κN)(hexa­methyl­disilyl­amido-κN)lithium, [Li(C6H18NSi2)(C11H13NO)2] or [Li{N(Si(CH3)3)2}(Phox)2] in high yield (89%). Despite the 1:1 proportion of the starting materials in the reaction mixture, the product formed with a 1:2 amide:oxazoline ratio. In the unit cell of the C2/c space group, the neutral mol­ecules lie on twofold rotation axes coinciding with the Li—N(amide) bonds. The lithium(I) centre adopts a trigonal–planar coordination geometry with three nitro­gen donor atoms, one from the HMDS anion and two from the oxazolines. All ligands are monodentate. In the phenyl­oxazoline units, the dihedral angle defined by the five-membered heterocyclic rings is 35.81 (5)°, while the phenyl substituents are approximately face-to-face, separated by 3.908 (5) Å. In the amide, the methyl groups assume a nearly eclipsed arrangement to minimize steric repulsion with the analogous substituents on the oxazoline rings. The non-covalent inter­actions in the solid-state structure of [Li{N(Si(CH3)3)2}(Phox)2] were assessed by Hirshfeld surface analysis and fingerprint plots. This new compound is attractive for catalysis due to its unique structural features.

Three organoplatinum(II) complexes bearing natural aryl­olefin and quinoline derivatives, namely, [4-meth­oxy-5-(2-meth­oxy-2-oxoeth­oxy)-2-(prop-2-en-1-yl)phen­yl](quinolin-8-olato)platinum(II), [Pt(C13H15O4)(C9H6NO)], (I), [4-meth­oxy-5-(2-oxo-2-propoxyeth­oxy)-2-(prop-2-en-1-yl)phen­yl](quinoline-2-carboxy­l­ato)platinum(II), [Pt(C15H19O4)(C10H6NO2)], (II), and chlorido­[4-meth­oxy-5-(2-oxo-2-propoxyeth­oxy)-2-(prop-2-en-1-yl)phen­yl](quinoline)­plat­inum(II), [Pt(C15H19O4)Cl(C9H7N)], (III), were synthesized and structurally characterized by IR and 1H NMR spectroscopy, and by single-crystal X-ray diffraction. The results showed that the cyclo­platinated aryl­olefin coordinates with PtII via the carbon atom of the phenyl ring and the C=Colefinic group. The deprotonated 8-hy­droxy­quinoline (C9H6NO) and quinoline-2-carb­oxy­lic acid (C10H6NO2) coordinate with the PtII atom via the N and O atoms in complexes (I) and (II) while the quinoline (C9H7N) coordinates via the N atom in (III). Moreover, the coordinating N atom in complexes (I)–(III) is in the cis position compared to the C=Colefinic group. The crystal packing is characterized by C—H⋯π, C—H⋯O [for (II) and (III)], C—H⋯Cl [for (III) and π–π [for (I)] inter­actions.

Three new 1H-indole derivatives, namely, 2-(bromo­meth­yl)-3-methyl-1-(phenyl­sulfon­yl)-1H-indole, C16H14BrNO2S, (I), 2-[(E)-2-(2-bromo-5-meth­oxy­phen­yl)ethen­yl]-3-methyl-1-(phenyl­sulfon­yl)-1H-indole, C24H20BrNO3S, (II), and 2-[(E)-2-(2-bromo­phen­yl)ethen­yl]-3-methyl-1-(phenyl­sulfon­yl)-1H-indole, C23H18BrNO2S, (III), exhibit nearly orthogonal orientations of their indole ring systems and sulfonyl-bound phenyl rings. Such conformations are favourable for inter­molecular bonding involving sets of slipped π–π inter­actions between the indole systems and mutual C—H⋯π hydrogen bonds, with the generation of two-dimensional monoperiodic patterns. The latter are found in all three structures, in the form of supra­molecular columns with every pair of successive mol­ecules related by inversion. The crystal packing of the compounds is additionally stabilized by weaker slipped π–π inter­actions between the outer phenyl rings (in II and III) and by weak C—H⋯O, C—H⋯Br and C—H⋯π hydrogen bonds. The structural significance of the different kinds of inter­actions agree with the results of a Hirshfeld surface analysis and the calculated inter­action energies. In particular, the largest inter­action energies (up to −60.8 kJ mol−1) are associated with pairing of anti­parallel indole systems, while the energetics of weak hydrogen bonds and phenyl π–π inter­actions are comparable and account for 13–34 kJ mol−1.

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.

The crystal structures of 2-[1'-(carb­oxy­meth­yl)-4,4'-bi­pyridine-1,1'-diium-1-yl]acetate tetra­fluoro­borate, C14H13N2O4+·BF4− or (Hbcbpy)(BF4), and neutral 1,1'-bis­(carboxyl­atometh­yl)-4,4'-bi­pyridine-1,1'-diium (bcbpy), C14H20N2O8, are reported. The asymmetric unit of the (Hbcbpy)(BF4) consists of a Hbcbpy+ monocation, a BF4− anion, and one-half of a water mol­ecule. The BF4− anion is disordered. Two pyridinium rings of the Hbcbpy+ monocation are twisted at a torsion angle of 30.3 (2)° with respect to each other. The Hbcbpy monocation contains a carb­oxy­lic acid group and a deprotonated carboxyl­ate group. Both groups exhibit both a long and a short C—O bond. The cations are linked by inter­molecular hydrogen-bonding inter­actions between the carb­oxy­lic acid and the deprotonated carboxyl­ate group to give one-dimensional zigzag chains. The asymmetric unit of the neutral bcbpy consists of one-half of the bcbpy and two water mol­ecules. In contrast to the Hbcbpy+ monocation, the neutral bcbpy mol­ecule contains two pyridinium rings that are coplanar with each other and a carboxyl­ate group with similar C—O bond lengths. The mol­ecules are connected by inter­molecular hydrogen-bonding inter­actions between water mol­ecules and carboxyl­ate groups, forming a three-dimensional hydrogen-bonding network.

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, C8H11PS, which melts below room temperature, was crystallized at low temperature. The P—S bond length is 1.9623 (5) Å and the major contributors to the Hirshfeld surface are H⋯H (58.1%), S⋯H/H⋯S (13.4%) and C⋯H/H⋯C contacts (11.7%).

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 crystal structures of 4-benzyl-1H-pyrazole (C10H10N2, 1) and 3,5-di­amino-4-benzyl-1H-pyrazole (C10H12N4, 2) were measured at 150 K. Although its different conformers and atropenanti­omers easily inter­convert in solution by annular tautomerism and/or rotation of the benzyl substituent around the C(pyrazole)—C(CH2) single bond (as revealed by 1H NMR spectroscopy), 1 crystallizes in the non-centrosymmetric space group P21. Within its crystal structure, the pyrazole and phenyl aromatic moieties are organized into alternating bilayers. Both pyrazole and phenyl layers consist of aromatic rings stacked into columns in two orthogonal directions. Within the pyrazole layer, the pyrazole rings form parallel catemers by N—H⋯N hydrogen bonding. Compound 2 adopts a similar bilayer structure, albeit in the centrosymmetric space group P21/c, with pyrazole N—H protons as donors in N—H⋯π hydrogen bonds with neighboring pyrazole rings, and NH2 protons as donors in N—H⋯N hydrogen bonds with adjacent pyrazoles and other NH2 moieties. The crystal structures and supra­molecular features of 1 and 2 are contrasted with the two known structures of their analogs, 3,5-dimethyl-4-benzyl-1H-pyrazole and 3,5-diphenyl-4-benzyl-1H-pyrazole.

The reaction of cadmium iodide with 3-amino­pyrazole (3-apz) in ethano­lic solution leads to tautomerization of the ligand and the formation of crystals of the title compound, catena-poly[[di­iodido­cadmium(II)]-bis­(μ-3-amino-1H-pyrazole)-κ2N2:N3;κ2N3:N2], [CdI2(C3H5N3)2]n or [CdI2(3-apz)2]n. Its asymmetric unit consists of a half of a Cd2+ cation, an iodide anion and a 3-apz mol­ecule. The Cd2+ cations are coordinated by two iodide anions and two 3-apz ligands, generating trans-CdN4I2 octa­hedra, which are linked into chains by pairs of the bridging ligands. In the crystal, the ligand mol­ecules and iodide anions of neighboring chains are linked through inter­chain hydrogen bonds into a di-periodic network. The inter­molecular contacts were qu­anti­fied using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing the relative qu­anti­tative contributions of the weak inter­molecular contacts.

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.

In the title mol­ecule, C11H11BrO3, the di­hydro­indene moiety is essentially planar but with a slight twist in the saturated portion of the five-membered ring. The meth­oxy groups lie close to the above plane. In the crystal, π-stacking inter­actions between six-membered rings form stacks of mol­ecules extending along the a-axis direction, which are linked by weak C—H⋯O and C—H⋯Br hydrogen bonds. A Hirshfeld surface analysis was performed showing H⋯H, O⋯H/H⋯O and Br⋯H/H⋯Br contacts make the largest contributions to inter­molecular inter­actions in the crystal.