In 2,2,5-trimethyl-1,3-dioxane-5-carb­oxy­lic acid, C8H14O4, the carboxyl group occupies an equatorial position on the 1,3-dioxane ring. In the crystal, O—H⋯O hydrogen bonds form chains of mol­ecules, which are linked into a three-dimensional network by C—H⋯O hydrogen bonds. The asymmetric unit of 2,2,5-trimethyl-1,3-dioxane-5-carb­oxy­lic anhydride, C16H26O7, consists of two independent mol­ecules, which are linked by C—H⋯O hydrogen bonds. In the crystal, these units are connected into corrugated layers two mol­ecules thick and parallel to the ab plane by additional C—H⋯O hydrogen bonds.

The solvated title salt, [Ir(C9H7N2)2(C8H6N2)]PF6·CH2Cl2, was obtained from the reaction between 1,8-naphthyridine (NAP) and an orthometalated iridium(III) precursor containing a 1-phenyl­pyrazole (ppz) ligand. The asymmetric unit comprises one [Ir(ppz)2(NAP)]+ cation, one PF6− counter-ion and one CH2Cl2 solvent mol­ecule. The central IrIII atom of the [Ir(ppz)2(NAP)]+ cation is distorted-octa­hedrally coordinated by four N atoms and two C atoms, whereby two N atoms stem from the NAP ligand while the ppz ligands ligate through one N and one C atom each. In the crystal, the [Ir(ppz)2(NAP)]+ cations and PF6− counter-ions are connected with each other through weak inter­molecular C—H⋯F hydrogen bonds. Together with an additional C—H⋯F inter­action involving the solvent mol­ecule, a three-dimensional network structure is formed.

In the title mol­ecule, C24H21N5O·H2O, the di­hydro­benzo­diazole moiety is not quite planar, while the whole mol­ecule adopts a U-shaped conformation in which there is a close approach of the two benzyl groups. In the crystal, chains of alternating mol­ecules and lattice water extending along [201] are formed by O—HUncoordW⋯ODhyr and O—HUncoordW⋯NTrz (UncoordW = uncoordinated water, Dhyr = di­hydro and Trz = triazole) hydrogen bonds. The chains are connected into layers parallel to (010) by C—HTrz⋯OUncoordW hydrogen bonds with the di­hydro­benzo­diazole units in adjacent layers inter­calating to form head-to-tail π-stacking [centroid-to-centroid distance = 3.5694 (11) Å] inter­actions between them, which generates the overall three-dimensional structure. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H⋯H (52.1%), H⋯C/C⋯H (23.8%) and O⋯H/H⋯O (11.2%) inter­actions. Hydrogen-bonding and van der Waals inter­actions are the dominant inter­actions in the crystal packing. Density functional theory (DFT) optimized structures at the B3LYP/ 6–311 G(d,p) level are compared with the experimentally determined mol­ecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

The title compound I, 2,2'-[(2-nitro­phen­yl)methyl­ene]bis­(3-hy­droxy-5,5-di­methyl­cyclo­hex-2-enone), C23H27NO6, features a 1,3-ketone–enol conformation which is stabilized by two intra­molecular hydrogen bonds. The most prominent inter­molecular inter­actions in compound I are C—H⋯O hydrogen bonds, which link mol­ecules into a two-dimensional network parallel to the (001) plane and a chain perpendicular to (1overline{1}1). Both title compounds II, ethyl 4-(4-hy­droxy-3,5-di­meth­oxy­phen­yl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexa­hydro­quinoline-3-carb­oxyl­ate, C23H29NO6, and III, ethyl 4-(anthracen-9-yl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexa­hydro­quinoline-3-carboxyl­ate, C29H29NO3, share the same structural features, such as a shallow boat conformation of the di­hydro­pyridine group and an orthogonal aryl group attached to the di­hydro­pyridine. Inter­molecular N—H⋯O bonding is present in the crystal packing of both compound II and III.

The equimolar reaction between a racemic mixture of (R)- and (S)-camphorquinone with thio­semicarbazide yielded the title compound, C11H17N3OS [common name: (R)- and (S)-camphor thio­semicarbazone], which maintains the chirality of the methyl­ated chiral carbon atoms and crystallizes in the centrosymmetric space group C2/c. There are two mol­ecules in general positions in the asymmetric unit, one of them being the (1R)-camphor thio­semicarbazone isomer and the second the (1S)- isomer. In the crystal, the mol­ecular units are linked by C—H⋯S, N—H⋯O and N—H⋯S inter­actions, building a tape-like structure parallel to the (overline{1}01) plane, generating R21(7) and R22(8) graph-set motifs for the H⋯S inter­actions. The Hirshfeld surface analysis indicates that the major contributions for crystal cohesion are from H⋯H (55.00%), H⋯S (22.00%), H⋯N (8.90%) and H⋯O (8.40%) inter­actions.

A mixed alkaline-earth powellite, Ca0.84Sr0.16MoO4 (calcium strontium molybdate), was synthesized by a flux method and its crystal structure was solved using single-crystal X-ray diffraction (SC-XRD) data. The compound crystallized in the I41/a space group as with a typical CaMoO4 powellite, but with larger unit-cell parameters and unit-cell volume as a result of the partial incorporation of larger Sr cations into the Ca sites within the crystal. The unit cell and volume were well fitted with the trendline calculated from literature values, and the powder X-ray diffraction (P-XRD) pattern of the ground crystal is in good agreement with the calculated pattern from the solved structure.

In the title compound, C18H15ClN2O·H2O, a benzohydrazide derivative, the dihedral angle between the mean plane of the di­hydro­naphthalene ring system and the phenyl ring is 17.1 (2)°. In the crystal, O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds link the benzohydrazide and water mol­ecules, forming a layer parallel to the bc plane. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H⋯H (45.7%) and H⋯C/C⋯H (20.2%) contacts.

The title compound, [Na(μ-C6F5BH3)(C4H8O)2]2, represents a dimeric structure of sodium and organoborohydride, located about a centre of inversion. The Na⋯B distances of 2.7845 (19) and 2.7494 (18) Å were apparently longer than the Li⋯B distances (2.403–2.537 Å) of the lithium organotri­hydro­borates in the previous reports. Moreover, an inter­action between the sodium atom and one fluorine atom on the 2-position of the benzene ring is observed [Na—F = 2.6373 (12) Å]. In the crystal, the dimeric mol­ecules are stacked along the b-axis via a π–π inter­action between the benzene rings.

The reaction of N-phenyl-1-(pyridin-2-yl)methanimine with copper chloride dihydrate produced the title neutral complex, [CuCl2(C12H10N2)(H2O)]·H2O. The CuII ion is five-coordinated in a distorted square-pyramidal geometry, in which the two N atoms of the bidentate Schiff base, as well as one chloro and a water mol­ecule, form the irregular base of the pyramidal structure. Meanwhile, the apical chloride ligand inter­acts through a strong hydrogen bond with a water mol­ecule of crystallization. In the crystal, mol­ecules are arranged in pairs, forming a stacking of symmetrical cyclic dimers that inter­act in turn through strong hydrogen bonds between the chloride ligands and both the coordinated and the crystallization water mol­ecules. The mol­ecular and electronic structures of the complex were also studied in detail using EPR (continuous and pulsed), FT–IR and Raman spectroscopy, as well as magnetization measurements. Likewise, Hirshfeld surface analysis was used to investigate the inter­molecular inter­actions in the crystal packing.

The asymmetric unit of the title 1:1 salt 1,2,4-triazolium hydrogen oxalate, C2H4N3+·C2HO4− (I), comprises one 1,2,4-triazolium cation and one hydrogen oxalate anion. In the crystal, the hydrogen oxalate anions are linked by O—H⋯O hydrogen bonds into chains running parallel to [100]. In turn, the anionic chains are linked through the 1,2,4-triazolium cations by charge-assisted +N—H⋯O− hydrogen bonds into sheets aligned parallel to (01overline{1}). The sheets are further stacked through π–π inter­actions between the 1,2,4-triazolium rings [centroid-to-centroid distance = 3.642 (3) Å, normal distance = 3.225 (3) Å, slippage 1.691 Å], resulting in the formation of a three-dimensional supra­molecular network. Hirshfeld surface analysis of the title salt suggests that the most significant contributions to the crystal packing are by H⋯O/O⋯H and H⋯N/N⋯H contacts involving the hydrogen bonds.

In the crystal structure of the title compound, C14H12ClNO, the mol­ecules are linked through C—H⋯O hydrogen bonds and C—H⋯π inter­actions, forming chains parallel to the [010] direction. π–π inter­actions and intra­molecular hydrogen bonds are also observed. The mol­ecular geometry of the title compound in the ground state has been calculated using density functional theory at the B3LYP level with the 6–311++G(2d,2p) basis set. Additionally, frontier mol­ecular orbital and mol­ecular electrostatic potential map analyses were performed.

Recrystallization of (E)-5-phenyl-1-(pyridin-2-yl)pent-2-en-4-yn-1-one at room temperature from ethyl­ene glycol in daylight afforded [3,4-bis­(phenyl­ethyn­yl)cyclo­butane-1,2-di­yl)bis­(pyridin-2-yl­methanone], C32H22N2O2 (3), while (E)-5-(4-methyl­phen­yl)-1-(pyridin-2-yl)pent-2-en-4-yn-1-one, C17H13NO (2), remained photoinert. This is the first experimental evidence that pentenynones can be photoreactive when fixed in nearly coplanar parallel positions. During the photoreaction, the bond lengths and angles along the pentenyne chain changed significantly, while the disposition of the pyridyl ring towards the keto group was almost unchanged. The cyclo­butane ring adopts an rctt conformation.

In the title compound, C18H19BrFN3S, the 1,2,4-triazole ring is nearly planar with a maximum deviation of −0.009 (3) and 0.009 (4) Å, respectively, for the S-bound C atom and the N atom bonded to the bromo­fluoro­phenyl ring. The phenyl and triazole rings are almost perpendicular to each other, forming a dihedral angle of 89.5 (2)°. In the crystal, the mol­ecules are linked by weak C—H⋯π(phen­yl) inter­actions, forming supra­molecular chains extending along the c-axis direction. The crystal packing is further consolidated by inter­molecular N—H⋯S hydrogen bonds and by weak C—H⋯S inter­actions, yielding double chains propagating along the a-axis direction. The crystal studied was refined as a racemic twin.

Crystals of the new compound, AgSr4Cu4.5(PO4)6, were grown successfully by the hydro­thermal process. The asymmetric unit of the crystal structure of the title compound contains 40 independent atoms (4 Sr, 4.5 Cu, 1 Ag, 6 P and 24 O), which are all in general positions except for one Cu atom, which is located on an inversion centre. The Cu atoms are arranged in CuOn (n = 4 or 5) polyhedra, linked through common oxygen corners to build a rigid three-dimensional motif. The connection of these copper units is assured by PO4 tetra­hedra. This arrangement allows the construction of layers extending parallel to the (100) plane and hosts suitable cavities in which Ag+ and Sr2+ cations are located. The crystal-structure cohesion is ensured by ionic bonds between the silver and strontium cations and the oxygen anions belonging to two adjacent sheets. Charge-distribution analysis and bond-valence-sum calculations were used to validate the structural model.

Deuterated potassium orthophosphate hepta­hydrate, K3PO4·7D2O, crystallizes in the Sohnke space group P21, and its absolute structure was determined from 2017 Friedel pairs [Flack parameter 0.004 (16)]. Each of the three crystallographically unique K+ cations is surrounded by six water mol­ecules and one oxygen atom from the orthophosphate group, using a threshold for K—O bonds of 3.10 Å. The highly irregular coordination polyhedra are linked by corner- and edge-sharing into a three-dimensional network that is consolidated by an intricate network of O—D⋯O hydrogen bonds of medium strength.

The title compound, C8H7NO5, is planar with an r.m.s. deviation for all non-hydrogen atoms of 0.018 Å. An intra­molecular O—H⋯O hydrogen bond involving the adjacent hy­droxy and nitro groups forms an S(6) ring motif. In the crystal, mol­ecules are linked by O—H⋯O hydrogen bonds, forming chains propagating along the b-axis direction. The chains are linked by C—H⋯O hydrogen bonds, forming layers parallel to the bc plane. The layers are linked by a further C—H⋯O hydrogen bond, forming slabs, which are linked by C=O⋯π inter­actions, forming a three-dimensional supra­molecular structure. Hirshfeld surface analysis was used to investigate inter­molecular inter­actions in the solid state. The mol­ecule was also characterized spectroscopically and its thermal stability investigated by differential scanning calorimetry and by thermogravimetric analysis.

The structure of the title quinoline carboxamide derivative, C26H25N3O, is described. The quinoline moiety is not planar as a result of a slight puckering of the pyridine ring. The secondary amine has a slightly pyramidal geometry, certainly not planar. Both intra- and inter­molecular hydrogen bonds are present. Hirshfeld surface analysis and lattice energies were used to investigate the inter­molecular inter­actions.

SrS2O3·H2O was obtained from an aqueous solution of Na2S2O3 and Sr(NO3)2 and crystallizes in space group Poverline{1} with all atoms at general positions. The Sr2+ ion exhibits an [8 + 1] coordination defined by two terminal S and six O atoms of thio­sulfate ions, one of the latter at a longer distance, and by one O atom of a water mol­ecule. Two thio­sulfate anions act as bidentate, four as monodentate ligands. The structure consists of mainly ionically inter­acting layers lying parallel to the crystallographic ab plane. The layers are connected by O—H⋯S and O—H⋯O hydrogen bonds of moderate strength.

A copper(II) dimer with the deprotonated anion of 2-bromo­nicotinic acid (2-BrnicH), namely, tetrakis(μ-2-bromonicotinato-κ2O:O')bis[aquacopper(­II)](Cu—Cu), [Cu2(H2O)2(C6H3BrNO2)4] or [Cu2(H2O)2(2-Brnic)4], (1), was prepared by the reaction of copper(II) chloride dihydrate and 2-bromo­nicotinic acid in water. The copper(II) ion in 1 has a distorted square-pyramidal coordination environment, achieved by four carboxyl­ate O atoms in the basal plane and the water mol­ecule in the apical position. The pair of symmetry-related copper(II) ions are connected into a centrosymmetric paddle-wheel dinuclear cluster [Cu⋯Cu = 2.6470 (11) Å] via four O,O'-bridging 2-bromo­nicotinate ligands in the syn-syn coordination mode. In the extended structure of 1, the cluster mol­ecules are assembled into an infinite two-dimensional hydrogen-bonded network lying parallel to the (001) plane via strong O—H⋯O and O—H⋯N hydrogen bonds, leading to the formation of various hydrogen-bond ring motifs: dimeric R22(8) and R22(16) loops and a tetra­meric R44(16) loop. The Hirshfeld surface analysis was also performed in order to better illustrate the nature and abundance of the inter­molecular contacts in the structure of 1.

The title compound, C7H3F5INS, a penta­fluoro­sulfanyl (SF5) containing arene, was synthesized from 4-(penta­fluoro­sulfan­yl)benzo­nitrile and lithium tetra­methyl­piperidide following a variation to the standard approach, which features simple and mild conditions that allow direct access to tri-substituted SF5 inter­mediates that have not been demonstrated using previous methods. The mol­ecule displays a planar geometry with the benzene ring in the same plane as its three substituents. It lies on a mirror plane perpendicular to [010] with the iodo, cyano, and the sulfur and axial fluorine atoms of the penta­fluoro­sulfanyl substituent in the plane of the mol­ecule. The equatorial F atoms have symmetry-related counterparts generated by the mirror plane. The penta­fluoro­sulfanyl group exhibits a staggered fashion relative to the ring and the two hydrogen atoms ortho to the substituent. S—F bond lengths of the penta­fluoro­sulfanyl group are unequal: the equatorial bond facing the iodo moiety has a longer distance [1.572 (3) Å] and wider angle compared to that facing the side of the mol­ecules with two hydrogen atoms [1.561 (4) Å]. As expected, the axial S—F bond is the longest [1.582 (5) Å]. In the crystal, in-plane C—H⋯F and N⋯I inter­actions as well as out-of-plane F⋯C inter­actions are observed. According to the Hirshfeld analysis, the principal inter­molecular contacts for the title compound are F⋯H (29.4%), F⋯I (15.8%), F⋯N (11.4%), F⋯F (6.0%), N⋯I (5.6%) and F⋯C (4.5%).

The title compound, C15H17NO2S, was synthesized via a substitution reaction between 4-methyl­benzyl­amine and p-toluene­sulfonyl chloride. In the crystal, N—H⋯O hydrogen bonds link the mol­ecules, forming ribbons running along the b-axis direction. One of the aromatic rings hosts two inter­molecular C—H⋯π inter­actions that link these hydrogen-bonded ribbons into a three-dimensional network.

The crystal structures of the title compounds, two solvates (CHCl3 and THF) of a symmetric and highly substituted porphyrin, C44H2Br8F20N4 or OBrTPFPP, are described. These structures each feature a non-planar porphyrin ring, exhibiting a similar conformation of the strained ring independent of solvent identity. These distorted porphyrins are able to form hydrogen bonds and sub-van der Waals halogen inter­actions with enclathrated solvent; supra­molecular inter­actions of proximal macrocycles are additionally affected by solvent choice. The crystal studied for compound 1·CHCl3 was refined as an inversion twin. One penta­fluoro­phenyl group was modelled as disordered over two sites [occupancy ratio = 0.462 (7):0.538 (7)]. The chloro­form solvate was also modelled as disordered over two orientations [occupancy ratio = 0.882 (7): 0.118 (7).

The asymmetric unit of the title 1:2 co-crystal, C14H14N4O2·2C7H5ClO2, comprises two half mol­ecules of oxalamide (4LH2), as each is disposed about a centre of inversion, and two mol­ecules of 4-chloro­benzoic acid (CBA), each in general positions. Each 4LH2 mol­ecule has a (+)anti­periplanar conformation with the pyridin-4-yl residues lying to either side of the central, planar C2N2O2 chromophore with the dihedral angles between the respective central core and the pyridyl rings being 68.65 (3) and 86.25 (3)°, respectively, representing the major difference between the independent 4LH2 mol­ecules. The anti conformation of the carbonyl groups enables the formation of intra­molecular amide-N—H⋯O(amide) hydrogen bonds, each completing an S(5) loop. The two independent CBA mol­ecules are similar and exhibit C6/CO2 dihedral angles of 8.06 (10) and 17.24 (8)°, indicating twisted conformations. In the crystal, two independent, three-mol­ecule aggregates are formed via carb­oxy­lic acid-O—H⋯N(pyrid­yl) hydrogen bonding. These are connected into a supra­molecular tape propagating parallel to [100] through amide-N—H⋯O(amide) hydrogen bonding between the independent aggregates and ten-membered {⋯HNC2O}2 synthons. The tapes assemble into a three-dimensional architecture through pyridyl- and methyl­ene-C—H⋯O(carbon­yl) and CBA-C—H⋯O(amide) inter­actions. As revealed by a more detailed analysis of the mol­ecular packing by calculating the Hirshfeld surfaces and computational chemistry, are the presence of attractive and dispersive Cl⋯C=O inter­actions which provide inter­action energies approximately one-quarter of those provided by the amide-N—H⋯O(amide) hydrogen bonding sustaining the supra­molecular tape.

A peptide biphenyl hybrid compound {systematic name: dimethyl 2,2'-[((2S,2'S)-2,2'-{[(2S,2'S)-1,1'-([1,1'-biphen­yl]-2,2'-dicarbon­yl)bis­(pyrrolidine-1,2-diyl-2-carbon­yl)]bis­(aza­nedi­yl)}bis­(3-phenyl­propano­yl))bis­(aza­nedi­yl)](2S,2'S)-dipropionate hemihydrate}, C50H56N6O10·0.5H2O, was prepared by coupling of [1,1'-biphen­yl]-2,2'-dicarbonyl dichloride, tri­ethyl­amine and the tripeptide Pro–Phe–Ala in CH2Cl2 at 273 K under an N2 atmosphere. In the crystal, the asymmetric unit contains the peptide biphenyl hybrid accompanied by one-half of a water mol­ecule. A C atom of one of the proline rings is disordered between two positions in a 0.746 (11):0.254 (11) ratio. An important structural aspect of peptide compounds is their capacity to self-associate mediated by inter­molecular and intra­molecular hydrogen bonding. This characteristic can be useful in understanding the inter­actions between peptides and biomacromolecular targets, as well as to explain peptide properties.

The crystal structure of the title compound, C10H13N·3H2O, a heterocyclic amine, was determined in the presence of water. The compound co-crystallizes with three water mol­ecules in the asymmetric unit, which leads to the formation of hydrogen bonding in the crystal.

The unit cell of the title compound, [Zn(C17H18N3O4)2]·CH4O·C2H6O, contains two complex mol­ecules related by an inversion centre, plus one methanol and one ethanol solvent molecule per complex molecule. In each complex, two deprotonated pyridine aroylhydrazone ligands {3,4,5-trimeth­oxy-N'-[1-(pyridin-2-yl)ethyl­idene]benzohydrazide} coordinate to the ZnII ion through the N atoms of the pyridine group and the ketamine, and, additionally, through the O atom of the enolate group. In the crystal, dimers are formed by π–π inter­actions between the planar ligand moieties, which are further connected by C⋯O and C⋯C inter­actions. The inter­molecular inter­actions were investigated using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing that the most important contributions for the crystal packing are from H⋯H (44.8%), H⋯C/C⋯H (22.2%), H⋯O/O⋯H (18.7%) and C⋯C (3.9%) inter­actions.

Two new mononuclear metal complexes involving the bidentate Schiff base ligand 2,4,6-trimethyl-N-[(pyridin-2-yl)methyl­idene]aniline (C15H16N2 or PM-TMA), [Mn(NCS)2(PM-TMA)2] (I) and [Ni(NCS)2(PM-TMA)2] (II), were synthesized and their structures determined by single-crystal X-ray diffraction. Although the title compounds crystallize in different crystal systems [triclinic for (I) and monoclinic for (II)], both asymmetric units consist of one-half of the complex mol­ecule, i.e. one metal(II) cation, one PM-TMA ligand, and one N-bound thio­cyanate anion. In both complexes, the metal(II) cation is located on a centre of inversion and adopts a distorted octa­hedral coordination environment defined by four N atoms from two symmetry-related PM-TMA ligands in the equatorial plane and two N atoms from two symmetry-related NCS− anions in a trans axial arrangement. The tri­methyl­benzene and pyridine rings of the PM-TMA ligand are oriented at dihedral angles of 74.18 (7) and 77.70 (12)° for (I) and (II), respectively. The subtle change in size of the central metal cations leads to a different crystal packing arrangement for (I) and (II) that is dominated by weak C—H⋯S, C—H⋯π, and π–π inter­actions. Hirshfeld surface analysis and two-dimensional fingerprint plots were used to qu­antify these inter­molecular contacts, and indicate that the most significant contacts in packing are H⋯H [48.1% for (I) and 54.9% for (II)], followed by H⋯C/C⋯H [24.1% for (I) and 15.7% for (II)], and H⋯S/S⋯H [21.1% for (I) and 21.1% for (II)].

A new pseudopolymorph of dodeca­chloro­penta­silane, namely a benzene monosolvate, Si5Cl12·C6H6, is described. There are two half mol­ecules of each kind in the asymmetric unit. Both Si5Cl12 mol­ecules are completed by crystallographic twofold symmetry. One of the benzene mol­ecules is located on a twofold rotation axis with two C—H groups located on this rotation axis. The second benzene mol­ecule has all atoms on a general position: it is disordered over two equally occupied orientations. No directional inter­actions beyond normal van der Waals contacts occur in the crystal.

The title compound, C24H27Cl2NOS, contains 1,4-benzo­thia­zine and 2,4-di­chloro­phenyl­methyl­idene units in which the di­hydro­thia­zine ring adopts a screw-boat conformation. In the crystal, inter­molecular C—HBnz⋯OThz (Bnz = benzene and Thz = thia­zine) hydrogen bonds form chains of mol­ecules extending along the a-axis direction, which are connected to their inversion-related counterparts by C—HBnz⋯ClDchlphy (Dchlphy = 2,4-di­chloro­phen­yl) hydrogen bonds and C—HDchlphy⋯π (ring) inter­actions. These double chains are further linked by C—HDchlphy⋯OThz hydrogen bonds, forming stepped layers approximately parallel to (012). The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (44.7%), C⋯H/H⋯C (23.7%), Cl⋯H/H⋯Cl (18.9%), O⋯H/H⋯O (5.0%) and S⋯H/H⋯S (4.8%) inter­actions. Hydrogen-bonding and van der Waals inter­actions are the dominant inter­actions in the crystal packing. Computational chemistry indicates that in the crystal, C—HDchlphy⋯OThz, C—HBnz⋯OThz and C—HBnz⋯ClDchlphy hydrogen-bond energies are 134.3, 71.2 and 34.4 kJ mol−1, respectively. Density functional theory (DFT) optimized structures at the B3LYP/6–311 G(d,p) level are compared with the experimentally determined mol­ecular structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap. The two carbon atoms at the end of the nonyl chain are disordered in a 0.562 (4)/0.438 (4) ratio.

In the title compound, [Zn(C50H36N6O5)], the ZnII cation is chelated by four pyrrole N atoms of the porphyrinate anion and coordinated by a symmetry-generated keto O atom of the diazo­ester group in a distorted square-pyramidal geometry. The mean Zn—N(pyrrole) bond length is 2.058 Å and the Zn—O(diazo­ester) bond length is 2.179 (4) Å. The zinc cation is displaced by 0.2202 (13) Å from the N4C20 mean plane of the porphyrinate anion toward the O atom; the involvement of this atom leads to a [100] polymeric chain in the crystal.

In the crystal structure of the title compound, [Fe(NCS)2(C12H9NO)2(CH4O)2], the FeII cations are octa­hedrally coordinated by two N atoms of 4-benzoyl­pyridine ligands, two N atoms of two terminal iso­thio­cyanate anions and two methanol mol­ecules into discrete complexes that are located on centres of inversion. These complexes are linked via inter­molecular O—H⋯O hydrogen bonds between the methanol O—H H atoms and the carbonyl O atoms of the 4-benzoyl­pyridine ligands, forming layers parallel to (101). Powder X-ray diffraction proved that a pure sample was obtained but that this compound is unstable and transforms into an unknown crystalline phase within several weeks. However, the solvent mol­ecules can be removed by heating in a thermobalance, which for the aged sample as well as the title compound leads to the formation of a compound with the composition Fe(NCS)2(4-benzoyl­pyridine)2, which exhibits a powder pattern that is similar to that of Mn(NCS)2(4-benzoyl­pyridine)2.

The pyran­opyran amide (2S,4aR,8aR)-6-oxo-2,4a,6,8a-tetra­hydro­pyrano[3,2-b]pyran-2-carboxamide, C9H9NO4, 3, was prepared by a chemoselective hydration of the corresponding nitrile, 2, using a heterogeneous catalytic method based on copper(II) supported on mol­ecular sieves, in the presence of acetaldoxime. Compound 3 belongs to a new class of pyran­opyrans that possess anti­bacterial and phytotoxic activity. Crystallographic analysis of 3 shows a bent structure for the cis-fused bicyclic pyran­opyran, similar to nitrile 2. Evidence of an intra­molecular hydrogen bond involving the amide group and ring oxygen was not observed; however, two separate inter­molecular hydrogen-bonding inter­actions were observed between the amide hydrogen atoms and adjacent carbonyl oxygen atoms along the b- and a-axis directions. The latter inter­action may also be supported by an inter­molecular C—H⋯O hydrogen bond. The lattice is filled out by close-packed layers of this hydrogen-bonded network along the c-axis direction, related from one to the next by a 21 screw axis.

The title compound, di­aqua­[tris­(2-amino­eth­yl)amine]­nickel(II) hexa­aqua­nickel(II) bis­(sulfate), [Ni(C6H18N4)(H2O)2][Ni(H2O)6](SO4)2 or [Ni(tren)(H2O)2][Ni(H2O)6](SO4)2, consists of two octa­hedral nickel complexes within the same unit cell. These metal complexes are formed from the reaction of [Ni(H2O)6](SO4) and the ligand tris­(2-amino­eth­yl)amine (tren). The crystals of the title compound are purple, different from those of the starting complex [Ni(H2O)6](SO4), which are turquoise. The reaction was performed both in a 1:1 and 1:2 metal–ligand molar ratio, always yielding the co-precipitation of the two types of crystals. The asymmetric unit of the title compound, which crystallizes in the space group Pnma, consists of two half NiII complexes and a sulfate counter-anion. The mononuclear cationic complex [Ni(tren)(H2O)2]2+ comprises an Ni ion, the tren ligand and two water mol­ecules, while the mononuclear complex [Ni(H2O)6]2+ consists of another Ni ion surrounded by six coordinated water mol­ecules. The [Ni(tren)(H2O)2] and [Ni(H2O)6] subunits are connected to the SO42− counter-anions through hydrogen bonding, thus consolidating the crystal structure.

The crystal structure of title salt, C14H36N44+·2ClO4−·2Cl−, has been determined using synchrotron radiation at 220 K. The structure determination reveals that protonation has occurred at all four amine N atoms. The asymmetric unit contains one half-cation (completed by crystallographic inversion symmetry), one perchlorate anion and one chloride anion. A distortion of the perchlorate anion is due to its involvement in hydrogen-bonding inter­actions with the cations. The crystal structure is consolidated by inter­molecular hydrogen bonds involving the 1,4,8,11-tetra­methyl-1,4,8,11-tetra­azonia­cyclo­tetra­decane N—H and C—H groups as donor groups, and the O atoms of the perchlorate and chloride anion as acceptor groups, giving rise to a three-dimensional network.

A new organic–inorganic hybrid salt [L]2[MnCl4] (I) where L+ is the 2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridinium cation, is built of discrete organic cations and tetra­chlorido­manganate(II) anions. The L+ cation was formed in situ in the oxidative cyclo­condensation of 2-pyridine­carbaldehyde and CH3NH2·HCl in methanol. The structure was refined as a two-component twin using PLATON (Spek, 2020) to de-twin the data. The twin law (−1 0 0 0 − 1 0 0.5 0 1) was applied in the refinement where the twin component fraction refined to 0.155 (1). The compound crystallizes in the space group P21/c with two crystallographically non-equivalent cations in the asymmetric unit, which possess similar structural conformations. The fused pyridinium and imidazolium rings of the cations are virtually coplanar [dihedral angles are 0.89 (18) and 0.78 (17)°]; the pendant pyridyl rings are twisted by 36.83 (14) and 36.14 (13)° with respect to the planes of the remaining atoms of the cations. The tetra­hedral MnCl42– anion is slightly distorted with the Mn—Cl distances falling in the range 2.3469 (10)–2.3941 (9) Å. The distortion value of 0.044 relative to the ideal tetra­hedron was obtained by continuous shape measurement (CShM) analysis. In the crystal, the cations and anions form separate stacks propagating along the a-axis direction. The organic cations display weak π–π stacking. The anions, which are stacked identically one above the other, demonstrate loose packing; the minimum Mn⋯Mn separation in the cation stack is approximately 7.49 Å. The investigation of the fluorescent properties of a powdered sample of (I) showed no emission. X-band EPR data for (I) at 293 and 77 K revealed broad fine structure signals, indicating moderate zero-field splitting.

The title compound, C20H36O2·CH3OH [systematic name: (3S)-4-[(S)-3-hy­droxy-3-methyl­pent-4-en-1-yl]-3,4a,8,8-tetra­methyl­deca­hydro­naphthalen-3-ol methanol monosolvate], is a methanol solvate of sclareol, a diterpene oil isolated from the medicinally important medicinal herb Salvia sclarea, commonly known as clary sage. It crystallizes in space group P1 (No. 1) with Z' = 2. The sclareol mol­ecule comprises two trans-fused cyclo­hexane rings, each having an equatorially oriented hydroxyl group, and a 3-methyl­pent-1-en-3-ol side chain. In the crystal, Os—H⋯Os, Os—H⋯Om, Om—H⋯Os and Om—H⋯Om (s = sclareol, m = methanol) hydrogen bonds connect neighboring mol­ecules into infinite [010] chains. The title compound exhibits weak anti-leishmanial activity (IC50 = 66.4 ± 1.0 µM ml−1) against standard miltefosine (IC50 = 25.8 ± 0.2 µM ml−1).

The title compound represents the thallium(I) salt of a substituted 1,2,5-oxa­diazole, [Tl(C3H3N4O3)]n, with amino- and hydroxamate groups in the 4- and 3- positions of the oxa­diazole ring, respectively. In the crystal, the deprotonated hydroxamate group represents an inter­mediate between the keto/enol tautomers and forms a five-membered chelate ring with the thallium(I) cation. The coordination sphere of the cation is augmented to a distorted disphenoid by two monodentately binding O atoms from two adjacent anions, leading to the formation of zigzag chains extending parallel to the b axis. The cohesion within the chains is supported by π–π stacking [centroid–centroid distance = 3.746 (3) Å] and inter­molecular N—H⋯N hydrogen bonds.

The whole mol­ecule of the cadmium(II) complex, di­iodido­{N,N',N'',N'''-[pyrazine-2,3,5,6-tetra­yltetra­kis­(methyl­ene)]tetra­kis­(N-methyl­aniline)-κ3N2,N1,N6}cadmium(II), [CdI2(C36H40N6)], (I), of the ligand N,N',N'',N'''-[pyrazine-2,3,5,6-tetra­yltetra­kis­(methyl­ene)]tetra­kis­(N-methyl­aniline) (L), is generated by a twofold rotation symmetry; the twofold axis bis­ects the cadmium atom and the nitro­gen atoms of the pyrazine ring. The ligand coordinates in a mono-tridentate manner and the cadmium atom has a fivefold CdN3I2 coordination environment with a distorted shape. In the zinc(II) complex, dichlorido{N,N',N'',N'''-[pyrazine-2,3,5,6-tetra­yltetra­kis­(methyl­ene)]tetra­kis­(N-methyl­aniline)-κ3N2,N1,N6}zinc(II) di­chloro­methane 0.6-solvate, [ZnCl2(C36H40N6)]·0.6CH2Cl2, (II), ligand L also coordinates in a mono-tridentate manner and the zinc atom has a fivefold ZnN3Cl2 coordination environment with a distorted shape. It crystallized as a partial di­chloro­methane solvate. In the crystal of I, the complex mol­ecules are linked by weak C—H⋯I contacts, forming ribbons propagating along [100]. In the crystal of II, the complex mol­ecules are linked by a series of C—H⋯π inter­actions, forming layers lying parallel to the (1overline{1}1) plane. In the crystals of both compounds there are metal–halide⋯π(pyrazine) contacts present. The Hirshfeld analyses confirm the importance of the C—H⋯halide contacts in the crystal packing of both compounds.

The asymmetric unit of the title compound, C23H28O4, comprises two half-mol­ecules, with the other half of each mol­ecule being completed by the application of twofold rotation symmetry. The two completed mol­ecules both have a V-shaped appearance but differ in their conformations. In the crystal, each independent mol­ecule forms chains extending parallel to the b axis with its symmetry-related counterparts through C—H⋯π(ring) inter­actions. Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (65.4%), H⋯C/C⋯H (21.8%) and H⋯O/O⋯H (12.3%) inter­actions. Optimized structures using density functional theory (DFT) at the B3LYP/6–311 G(d,p) level are compared with the experimentally determined mol­ecular structures in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

In the title mol­ecule, C12H13N3O2S, the benzo­thia­zine moiety is slightly non-planar, with the imidazolidine portion twisted only a few degrees out of the mean plane of the former. In the crystal, a layer structure parallel to the bc plane is formed by a combination of O—HHydethy⋯NThz hydrogen bonds and weak C—HImdz⋯OImdz and C—HBnz⋯OImdz (Hydethy = hy­droxy­ethyl, Thz = thia­zole, Imdz = imidazolidine and Bnz = benzene) inter­actions, together with C—HImdz⋯π(ring) and head-to-tail slipped π-stacking [centroid-to-centroid distances = 3.6507 (7) and 3.6866 (7) Å] inter­actions between thia­zole rings. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (47.0%), H⋯O/O⋯H (16.9%), H⋯C/C⋯H (8.0%) and H⋯S/S⋯H (7.6%) inter­actions. Hydrogen bonding and van der Waals inter­actions are the dominant inter­actions in the crystal packing. Computational chemistry indicates that in the crystal, C—H⋯N and C—H⋯O hydrogen-bond energies are 68.5 (for O—HHydethy⋯NThz), 60.1 (for C—HBnz⋯OImdz) and 41.8 kJ mol−1 (for C—HImdz⋯OImdz). Density functional theory (DFT) optimized structures at the B3LYP/6–311 G(d,p) level are compared with the experimentally determined mol­ecular structure in the solid state.

Chalcones of type 4-XC6H4C(O)CH=CHC6H4(OCH2CCH)-4, where X = Cl, Br or MeO, have been converted to the corresponding 4,5-di­hydro­pyrazole-1-carbo­thio­amides using a cyclo­condensation reaction with thio­semicarbazide. The chalcones 1-(4-chloro­phen­yl)-3-[4-(prop-2-yn­yloxy)phen­yl]prop-2-en-1-one, C18H13ClO2, (I), and 1-(4-bromo­phen­yl)-3-[4-(prop-2-yn­yloxy)phen­yl]prop-2-en-1-one, C18H13BrO2, (II), are isomorphous, and their mol­ecules are linked into sheets by two independent C—H⋯π(arene) inter­actions, both involving the same aryl ring with one C—H donor approaching each face. In each of the products (RS)-3-(4-chloro­phen­yl)-5-[4-(prop-2-yn­yloxy)phen­yl]-4,5-di­hydro­pyrazole-1-carbo­thio­amide, C19H16ClN3OS, (IV), (RS)-3-(4-bromo­phen­yl)-5-[4-(prop-2-yn­yloxy)phen­yl]-4,5-di­hydro­pyrazole-1-carbo­thio­amide, C19H16BrN3OS, (V), and (RS)-3-(4-meth­oxy­phen­yl)-5-[4-(prop-2-yn­yloxy)phen­yl]-4,5-di­hydro­pyrazole-1-carbo­thio­amide, C20H19N3O2S, (VI), the reduced pyrazole ring adopts an envelope conformation with the C atom bearing the 4-prop-2-yn­yloxy)phenyl substituent, which occupies the axial site, displaced from the plane of the four ring atoms. Compounds (IV) and (V) are isomorphous and their mol­ecules are linked into chains of edge-fused rings by a combination of N—H⋯S and C—H⋯S hydrogen bonds. The mol­ecules of (VI) are linked into sheets by a combination of N—H⋯S, N—H⋯N and C—H⋯π(arene) hydrogen bonds. Comparisons are made with the structures of some related compounds.

Three huntite-type aluminoborates of stoichiometry REAl3(BO3)4 (RE = Tb, Dy and Ho), namely, terbium/dysprosium/holmium trialuminium tetrakis(borate), were synthesized by slow cooling within a K2Mo3O10 flux with spontaneous crystallization. The crystal structures were determined using single-crystal X-ray diffraction (SC-XRD) data. The synthesized borates are isostructural to the huntite [CaMg3(CO3)4] structure and crystallized within the trigonal R32 space group. The structural parameters were compared to literature data of other huntite REAl3(BO3)4 crystals within the R32 space group. All three borates fit well into the trends calculated from the literature data. The unit-cell parameters and volumes increase linearly with larger RE cations whereas the densities decrease. All of the crystals studied were refined as inversion twins.

The title pyrazine dicarboxamide ligand, N2,N3-bis­(quinolin-8-yl)pyrazine-2,3-dicarboxamide (H2L1), C24H16N6O2, has a twisted conformation with the outer quinoline groups being inclined to the central pyrazine ring by 9.00 (6) and 78.67 (5)°, and by 79.94 (4)° to each other. In the crystal, molecules are linked by C—H⋯O hydrogen bonds, forming layers parallel to the (10overline{1}) plane, which are in turn linked by offset π–π inter­actions [inter­centroid distances 3.4779 (9) and 3.6526 (8) Å], forming a supra­molecular three-dimensional structure. Reaction of the ligand H2L1 with Cu(ClO4)2 in aceto­nitrile leads to the formation of the binuclear complex, [μ-(3-{hy­droxy[(quinolin-8-yl)imino]­meth­yl}pyrazin-2-yl)[(quinolin-8-yl)imino]­methano­lato]bis­[diaceto­nitrile­copper(II)] tris­(per­chlor­ate) aceto­nitrile disolvate, [Cu2(C24H15N6O2)(CH3CN)4](ClO4)3·2CH3CN or [Cu2(HL1−)(CH3CN)4](ClO4)3·2CH3CN (I). In the cation of complex I, the ligand coordinates to the copper(II) atoms in a bis-tridentate fashion. A resonance-assisted O—H⋯O hydrogen bond is present in the ligand; the position of this H atom was located in a difference-Fourier map. Both copper(II) atoms are fivefold coordinate, being ligated by three N atoms of the ligand and by the N atoms of two aceto­nitrile mol­ecules. The first copper atom has a perfect square-pyramidal geometry while the second copper atom has a distorted shape. In the crystal, the cation and perchlorate anions are linked by a number of C—H⋯O hydrogen bonds, forming a supra­molecular three-dimensional structure.

The title compound, C13H16ClNO, contains a methyl­piperidine ring in the stable chair conformation. The mean plane of the twisted piperidine ring subtends a dihedral angle of 39.89 (7)° with that of the benzene ring. In the crystal, weak C—H⋯O inter­actions link the mol­ecules along the a-axis direction to form infinite mol­ecular chains. H⋯H inter­atomic inter­actions, C—H⋯O inter­molecular inter­actions and weak dispersive forces stabilize mol­ecular packing and form a supra­molecular network, as established by Hirshfeld surface analysis.

Single crystals of sodium copper(II) indium bis­[phosphate(V)], NaCuIn(PO4)2, were grown from the melt under atmospheric conditions. The title phosphate crystallizes in the space group P21/n and is isotypic with KCuFe(PO4)2. In the crystal, two [CuO5] trigonal bipyramids share an edge to form a dimer [Cu2O8] that is connected to two PO4 tetra­hedra. The obtained [Cu2P2O12] units are inter­connected through vertices to form sheets that are sandwiched between undulating layers resulting from the junction of PO4 tetra­hedra and [InO6] octa­hedra. The two types of layers are alternately stacked along [101] and are joined into a three-dimensional framework through vertex- and edge-sharing, leaving channels parallel to the stacking direction. The channels host the sodium cations that are surrounded by four oxygen atoms in form of a distorted disphenoid.

In the title compound, [Cu(C16H8Br3N2O)2]·C2H6OS, the CuII atom is tetra­coordinated in a square-planar coordination, being surrounded by two N atoms and two O atoms from two N,O-bidentate (E)-1-[(2,4,6-tri­bromo­phen­yl)diazen­yl]naphthalen-2-olate ligands. The two N atoms and two O atoms around the metal center are trans to each other, with an O—Cu—O bond angle of 177.90 (16)° and a N—Cu—N bond angle of 177.8 (2)°. The average distances between the CuII atom and the coordinated O and N atoms are 1.892 (4) and 1.976 (4) Å, respectively. In the crystal, complexes are linked by C—H⋯O hydrogen bonds and by π–π inter­actions involving adjacent naphthalene ring systems [centroid–centroid distance = 3.679 (4) Å]. The disordered DMSO mol­ecules inter­act weakly with the complex mol­ecules, being positioned in the voids left by the packing arrangement of the square-planar complexes. The DMSO solvent mol­ecule is disordered over two positions with occupancies of 0.70 and 0.30.

The central thia­zolidine ring of the title salt, C16H16N3S+·Br−, adopts an envelope conformation, with the C atom bearing the phenyl ring as the flap atom. In the crystal, the cations and anions are linked by N—H⋯Br hydrogen bonds, forming chains parallel to the b-axis direction. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H⋯H (46.4%), C⋯H/H⋯C (18.6%) and H⋯Br/Br⋯H (17.5%) inter­actions.

The crystal structure of the polymeric title compound, catena-poly[[[di­aqua­lithium]-μ-γ-cyclo­dextrin(1−)-[aqua­lithium]-μ-γ-cyclo­dextrin(1−)] pentadecahydrate], {[Li2(C48H79O40)2(H2O)3]·15H2O}n, consists of deprotonated γ-cyclo­dextrin (CD) mol­ecules assembled by lithium ions into metal–organic ribbons that are cross-linked by multiple O—H⋯O hydrogen bonds into sheets extending parallel to (0overline11). Within a ribbon, one Li+ ion is coordinated by one deprotonated hydroxyl group of the first γ-CD torus and by one hydroxyl group of the second γ-CD torus as well as by two water mol­ecules. The other Li+ ion is coordinated by one deprotonated hydroxyl and by one hydroxyl group of the second γ-CD torus, by one hydroxyl group of the first γ-CD torus as well as by one water mol­ecule. The coordination spheres of both Li+ cations are distorted tetra­hedral. The packing of the structure constitute channels along the a axis. Parts of the hy­droxy­methyl groups in cyclo­dextrin molecules as well as water mol­ecules show two-component disorder. Electron density associated with additional disordered solvent mol­ecules inside the cavities was removed with the SQUEEZE [Spek (2015). Acta Cryst. C71, 9–18] routine in PLATON. These solvent mol­ecules are not considered in the given chemical formula and other crystal data. Five out of the sixteen hy­droxy­methyl groups and one water mol­ecule are disordered over two sets of sites.

A coordination polymer formulated as [Sr(H2BTEC)(H2O)]n (H4BTEC = benzene-1,2,4,5-tetra­carb­oxy­lic acid, C10H6O8), was synthesized hydro­thermally and characterized by single-crystal and powder X-ray diffraction, scanning electron microscopy and thermal analysis. Its crystal structure is made up of a zigzag inorganic chain formed by edge-sharing of [SrO8] polyhedra running along [001]. Adjacent chains are connected to each other via the carboxyl­ate groups of the ligand, resulting in a double-layered network extending parallel to (100). O—H⋯O hydrogen bonds of medium-to-weak strength between the layers consolidate the three-dimensional structure. One of the carb­oxy­lic OH functions was found to be disordered over two sets of sites with half-occupancy.

The title compound, C17H18ClNO2, was prepared and isolated as a pure diastereoisomer, using column chromatography followed by a succession of fractional crystallizations. Its exact structure was fully identified via 1H NMR and confirmed by X-ray diffraction. It is built up from a central five-membered di­hydro­isoxazole ring to which a p-chloro­phenyl group and a cyclo­hex-2-enone ring are attached in the 3 and 5 positions. The cyclo­hex-2-one and isoxazoline rings each exhibit an envelope conformation. The crystal packing features C—H⋯O, C—H⋯N and C—H⋯π inter­actions, which generate a three-dimensional network.