The paper reports the structure of a Δ1-pyrroline-2-carboxylate reductase from the archaeon Thermococcus litoralis, a key enzyme involved in the second step of trans-4-Hydroxy-L-proline metabolism, conserved in archaea, bacteria and humans.

The asymmetric unit of the title MOF, [Zn5(C14H5NO10S2)2(OH)2(H2O)10]n comprises three ZnII atoms, one of which is located on a centre of inversion, a tetra-negative carboxyl­ate ligand, one μ3-hydroxide and five water mol­ecules, each of which is coordinated. The ZnII atom, lying on a centre of inversion, is coordinated by trans sulfoxide-O atoms and four water mol­ecules in an octa­hedral geometry. Another ZnII atom is coordinated by two carboxyl­ate-O atoms, one hy­droxy-O, one sulfoxide-O and a water-O atom to define a distorted trigonal–bipyramidal geometry; a close Zn⋯O(carboxyl­ate) inter­action derived from an asymmetrically coordinating ligand (Zn—O = 1.95 and 3.07 Å) suggests a 5 + 1 coordination geometry. The third ZnII atom is coordinated in an octa­hedral fashion by two hy­droxy-O atoms, one carboxyl­ate-O, one sulfoxide-O and two water-O atoms, the latter being mutually cis. In all, the carboxyl­ate ligand binds six ZnII ions leading to a three-dimensional architecture. In the crystal, all acidic donors form hydrogen bonds to oxygen acceptors to contribute to the stability of the three-dimensional architecture.

The title compound, [Co(NCS)2(C15H22N2O2)2] or C32H44CoN6O4S2, was prepared from cobalt(II) nitrate, benzyl carbazate and ammonium thio­cyanate in the presence of 4-hepta­none. The compound crystallizes with two centrosymmetric complexes in which the cobalt(II) atoms have a trans-CoO2N4 octa­hedral coordination geometry. In the crystal, N—H⋯S, C—H⋯S and C—H⋯.π contacts stack the complex mol­ecules along the b-axis direction.

In the title compound, [Cd2(C9H6O5)2(H2O)2]n, the crystallographically distinct CdII cations are coordinated in penta­gonal–bipyramidal and octa­hedral fashions. The 2-(carb­oxy­meth­oxy)benzoate (cmb) ligands connect the Cd atoms into [Cd2(cmb)2(H2O)2)]n coordination polymer ribbons that are oriented along the a-axis direction. Supra­molecular layers are formed parallel to (01overline{1}) by O—H⋯O hydrogen bonding between the ribbons. The supra­molecular three-dimensional crystal structure of the title compound is then constructed by π–π stacking inter­actions with a centroid–centroid distance of 3.622 (2) Å between cmb ligands in adjacent layer motifs.

In the title compound, C14H14ClFN2O2S, the di­hydro­pyrimidine ring adopts a shallow-boat conformation and subtends a dihedral angle of 81.91 (17)° with the phenyl ring. In the crystal, N—H⋯O, N—H⋯S and C—H⋯F hydrogen bonds and C—H⋯π inter­actions are found.

In the title compound, C11H10N2OS, the dihedral angle between the thio­phene and pyridine rings is 77.79 (8)°. In the crystal, inversion dimers linked by pairs of N—H⋯N hydrogen bonds generate R22(10) loops. The dimers are reinforced by pairs of C—H⋯N inter­actions and C—H⋯O inter­actions link the dimers into [010] chains.

In the title compound, [Cd(C10H8O4)(H2O)2)]n, the CdII cation is coordinated in a distorted trigonal–prismatic fashion. 3-(4-Carb­oxy­phen­yl)propionate (cpp) ligands connect the CdII cations into zigzag [Cd(cpp)(H2O)2)]n coordination polymer chains, which are oriented parallel to [101]. The chains aggregate into supra­molecular layers oriented parallel to (10overline{1}) by means of O—H⋯O hydrogen bonding between bound water mol­ecules and ligating cpp carboxyl­ate O atoms. The layers stack in an ABAB pattern along [100] via other O—H⋯O hydrogen-bonding mechanisms also involving the bound water mol­ecules. The crystal studied was an inversion twin.

In the title compound, [Zn(C9H6O4)]n, the ZnII cations are coordinated in a tetra­hedral fashion by carboxyl­ate O-atom donors belonging to four 4-(carb­oxy­meth­yl) benzoate (4-cmb) ligands. Each 4-cmb ligand binds to four ZnII cations in an exo­tetra­dentate fashion to create a non-inter­penetrated [Zn(4-cmb)]n three-dimensional coordination polymer network with a new non-diamondoid 66 topology. The crystal studied was refined as an inversion twin.

In the title complex, [Ni(C7H3NO4)(C15H11N3)]·C3H7NO·H2O, the NiII ion is six-coordinated within an octa­hedral geometry defined by three N atoms of the 2,2':6',2''-terpyridine ligand, and two O atoms and the N atom of the pyridine-2,6-di­carboxyl­ate di-anion. In the crystal, the complex mol­ecules are stacked in columns parallel to the a axis being connected by π–π stacking [closest inter-centroid separation between pyridyl rings = 3.669 (3) Å]. The connections between columns and solvent mol­ecules to sustain a three-dimensional architecture are of the type water-O—H⋯O(carbon­yl) and pyridyl-, methyl-C—H⋯O(carbon­yl).

The asymmetric unit of the title compound, C8H15N3S, contains two independent mol­ecules. In both mol­ecules, the seven-membered cyclo­heptane ring adopts a chair conformation. An intra­molecular N—H⋯N hydrogen bond is observed in both mol­ecules, forming S(5) graph-set motifs. In the crystal, the two independent mol­ecules are connected through N—H⋯S hydrogen bonds, forming dimers which are in turn further connected by N—H⋯S hydrogen bonds into chains along [010].

The title compound, C6H3BrN2, also known as 3-bromo­picolino­nitrile, was synthesized by cyanation of 2,3-di­bromo­pyridine. In the solid state, short inter­molecular Br⋯N contacts are observed. Additionally, the crystal packing is consolidated by π–π stacking inter­actions with centroid–centroid distances of 3.7893 (9) Å.

The title complex, [Os3(C2H4N)H(CO)10] or [Os3(CO)10(μ-H)(μ-HN=C—CH3-1κN:2κC)], was synthesized in 41.6% yield by reactions between Os3(CO)11(CH3CN) and 2,4,6-tri­methyl­hexa­hydro-1,3,5-triazine. The central osmium triangle has two OsI atoms bridged by a hydride ligand and a μ-HN= C—CH3-1κN:2κC triazine fragment. Three CO ligands complete the coordination sphere around each OsI atom, while the remaining Os0 atom has four CO ligands. Each Os atom exhibits a pseudo-octa­hedral coordination environment, discounting the bridging Os—Os bond.

The title compound, C26H22O2P+·PF6−·C4H7O, crystallizes as a cation-anion pair with a single solvent mol­ecule in the asymmetric unit. Hydrogen bonding occurs between the carb­oxy­lic acid group on the cation and the oxygen atom of the solvent mol­ecule. Longer hydrogen-bonding inter­actions are observed between fluorine atoms of the anion and H atoms on the phenyl rings of the cation.

The title compound, C12H11N3O2S, was synthesized by a condensation reaction of 2-acetyl­indan-1,3-dione and thio­semicarbazide in ethanol in the presence of glacial acetic acid. The mol­ecule adopts a thio­ketone form. The dihedral angle between the mean planes of 1H-inden-1,3(2H)-dione and hydrazinecarbo­thio­amide units is 86.32 (7)°. Weak intra­molecular N—H⋯O and C—H⋯O hydrogen bonds are observed. In the crystal, mol­ecules are linked via pairs of weak inter­molecular N—H⋯O hydrogen bonds, forming inversion dimers. The dimers are further linked into a three-dimensional network through N—H⋯S and N—H⋯O hydrogen bonds, and π–π inter­actions [centroid–centroid distances = 3.5619 (10)–3.9712 (9) Å].

The title compound, C22H22O5, crystallizes with two mol­ecules in the asymmetric unit, one of which shows disorder of its ethyl acetate group over two sets of sites in a 0.880 (2):0.120 (2) ratio. The C≡C distances in the two mol­ecules are almost the same [1.1939 (16) and 1.199 (2) Å], but the Csp3—C≡C angles differ somewhat [175.92 (12) and 172.53 (16)°]. In the crystal, several weak C—H⋯O inter­actions are seen.

In the title compound, [Pd(C7H3NO4)(C10H8N2)]·H2O, the PdII cation is four-coordinated in a distorted square-planar coordination geometry defined by the two N atoms of the 2,2'-bi­pyridine ligand, one O atom and one N atom from the pyridine-2,6-di­carboxyl­ate anion. The complex and solvent water mol­ecule are linked by inter­molecular hydrogen bonds. In the crystal, the complex mol­ecules are stacked in columns along the a axis.

In the title compound, C29H26ClNO4, the di­hydro­pyridine ring adopts a shallow boat conformation. The mean plane of the di­hydro­pyridine ring (all atoms) subtends dihedral angles of 66.54 (1), 73.71 (1) and 79.47 (1)° with the two phenyl rings and the chloro­phenyl ring, respectively. In the crystal, N—H⋯O hydrogen bonds link the mol­ecules into [001] chains.

In the title compound, C18H16N2O2, the dihedral angle between the pyrrole rings is 79.47 (9)°, with the N—H groups approximately orthogonal (H—N⋯N—H pseudo torsion angle = −106°). In the crystal, N—H⋯O hydrogen bonds link the mol­ecules into [11overline{1}] chains. A C—H⋯O inter­action is also observed.

In the title hydrated Schiff base, C13H12N4O3·H2O, the dihedral angle between the aromatic rings is 5.06 (11)° and an intra­molecular O—H⋯N hydrogen bond closes an S(6) ring. In the crystal, Ow—H⋯O and Ow—H⋯N (w = water) hydrogen bonds link the components into centrosymmetric tetra­mers (two Schiff bases and two water mol­ecules). Longer N—H⋯O hydrogen bonds link the tetra­mers into [010] chains. A weak C—H⋯O hydrogen bond and aromatic π–π stacking between the pyrazine and phenyl rings [centroid–centroid separations = 3.604 (2) and 3.715 (2) Å] are also observed.

In the title compound, C16H21N3O4, the 1,4-di­hydro­pyridine ring adopts a flattened boat conformation, with the imidazole substituent in an axial orientation [dihedral angle between ring planes = 82.9 (6)°]. In the crystal structure, pairs of N—H⋯O and N—H⋯N hydrogen bonds with graph-set notation R22(14) connect the mol­ecules into chains running along the c-axis direction.

The title carbonate hydrate, Cs2Mg4(CO3)5·10H2O, was crystallized at room temperature out of aqueous solutions containing caesium bicarbonate and magnesium nitrate. Its monoclinic crystal structure (P21/n) consists of double chains of composition 1∞[Mg(H2O)2/1(CO3)3/3], isolated [Mg(H2O)(CO3)2]2– units, two crystallographically distinct Cs+ ions and a free water mol­ecule. The crystal under investigation was twinned by reticular pseudomerohedry.

In the title compound, C10H13N5, the piperidine ring adopts a chair conformation with the exocyclic N—C bond in an axial orientation, and the dihedral angle between the mean planes of piperidine and pyrimidine rings is 49.57 (11)°. A short intra­molecular C—H⋯N contact generates an S(7) ring. In the crystal, N—H⋯N hydrogen bonds link the mol­ecules into (100) sheets and a weak aromatic π-π stacking inter­action is observed [centroid–centroid separation = 3.5559 (11) Å] between inversion-related pyrimidine rings.

The crystal structure of the title mol­ecular complex, [Ag2{VO2F2}2(C13H17N3O2)4]·4H2O, supported by the heterofunctional ligand tr-ad-COOH [1-(1,2,4-triazol-4-yl)-3-carb­oxy­adamantane] is reported. Four 1,2,4-triazole groups of the ligand link two AgI atoms, as well as AgI and VV centres, forming the heterobimetallic coordination cluster {AgI2(VVO2F2)2(tr)4}. VV exists as a vanadium oxofluoride anion and possesses a distorted trigonal–bipyramidal coordination environment [VO2F2N]. A carb­oxy­lic acid functional group of the ligand stays in a neutral form and is involved in hydrogen bonding with solvent water mol­ecules and VO2F2− ions of adjacent mol­ecules. The extended hydrogen-bonding network is responsible for the crystal packing in the structure.

The asymmetric unit of the title compound, C14H14O6, a monomeric compound of poly(butyl­ene 2,5-furandi­carboxyl­ate), consists of one half-mol­ecule, the whole all-trans mol­ecule being generated by an inversion centre. In the crystal, the mol­ecules are inter­connected via C—H⋯O inter­actions, forming a mol­ecular sheet parallel to (10overline{2}). The mol­ecular sheets are further linked by C—H⋯π inter­actions.

The title benzo­furan derivatives 2-amino-5-hy­droxy-4-(4-nitro­phen­yl)benzo­furan-3-carboxyl­ate (BF1), C19H18N2O6, and 2-meth­oxy­ethyl 2-amino-5-hy­droxy-4-(4-nitro­phen­yl)benzo­furan-3-carboxyl­ate (BF2), C18H16N2O7, recently attracted attention because of their promising anti­tumoral activity. BF1 crystallizes in the space group Poverline{1}. BF2 in the space group P21/c. The nitro­phenyl group is inclined to benzo­furan moiety with a dihedral angle between their mean planes of 69.2 (2)° in BF1 and 60.20 (6)° in BF2. A common feature in the mol­ecular structures of BF1 and BF2 is the intra­molecular N—H⋯Ocarbon­yl hydrogen bond. In the crystal of BF1, the mol­ecules are linked head-to-tail into a one-dimensional hydrogen-bonding pattern along the a-axis direction. In BF2, pairs of head-to-tail hydrogen-bonded chains of mol­ecules along the b-axis direction are linked by O—H⋯Ometh­oxy hydrogen bonds. In BF1, the butyl group is disordered over two orientations with occupancies of 0.557 (13) and 0.443 (13).

Six reaction products of ZnII and NiII with pyridine-2,6-di­carb­oxy­lic acid (H2Lig1), 4-chloro­pyridine-2,6-di­carb­oxy­lic acid (H2Lig2) and 4-hy­droxy­pyridine-2,6-di­carb­oxy­lic acid (H2Lig3) are used to pinpoint the structural consequences of crystal field stabilization by an incomplete d shell. The pseudo-octa­hedral ZnII coordination sphere in bis­(6-carb­oxy­picolinato)zinc(II) trihydrate, [Zn(C7H4NO4)2]·3H2O or [Zn(HLig1)2]·3H2O, (1), is significantly less regular than that about NiII in the isostructural compound bis­(6-carb­oxy­picolinato)nickel(II) trihydrate, [Ni(C7H4NO4)2]·3H2O or [Ni(HLig1)2]·3H2O, (2). The ZnII complexes poly[(4-chloro­pyridine-2,6-di­carboxyl­ato)zinc(II)], [Zn(C7H2ClNO4)]n or [Zn(Lig2)]n, (3), and poly[[(4-hy­droxy­pyridine-2,6-di­carboxyl­ato)zinc(II)] monohydrate], {[Zn(C7H3NO5)]·H2O}n or {[Zn(Lig3)]·H2O}n, (4), represent two-dimensional coordination polymers with chelating and bridging pyridine-2,6-di­carboxyl­ate ligands in which the coordination polyhedra about the central cations cannot be associated with any regular shape; their coordination environments range between trigonal–bipyramidal and square-pyramidal geometries. In contrast, the corresponding adducts of the diprotonated ligands to NiII, namely tri­aqua­(4-chloro­pyridine-2,6-di­carboxyl­ato)nickel(II), [Ni(C7H2ClNO4)(H2O)3] or [NiLig2(OH2)3)], (5), and tri­aqua­(4-hy­droxy­pyridine-2,6-di­carboxyl­ato)nickel(II) 1.7-hydrate, [Ni(C7H3NO5)(H2O)3]·1.7H2O or [NiLig3(OH2)3)]·1.7H2O, (6), feature rather regular octa­hedral coordination spheres about the transition-metal cations, thus precluding the formation of analogous extended structures.

In the title quinoline derivative, C14H14ClNO3, there is an intra­molecular C—H⋯O hydrogen bond forming an S(6) graph-set motif. The mol­ecule is essentially planar with the mean plane of the ethyl acetate group making a dihedral angle of 5.02 (3)° with the ethyl 6-chloro-2-eth­oxy­quinoline mean plane. In the crystal, offset π–π inter­actions with a centroid-to-centroid distance of 3.4731 (14) Å link inversion-related mol­ecules into columns along the c-axis direction. Hirshfeld surface analysis indicates that H⋯H contacts make the largest contribution (50.8%) to the Hirshfeld surface.

The synthesis, spectroscopic data and crystal and mol­ecular structures of four 3-(3-phenyl­prop-1-ene-3-one-1-yl)thio­phene derivatives, namely 1-(4-hydroxy­phen­yl)-3-(thio­phen-3-yl)prop-1-en-3-one, C13H10O2S, (1), 1-(4-meth­oxy­phen­yl)-3-(thio­phen-3-yl)prop-1-en-3-one, C14H12O2S, (2), 1-(4-eth­oxy­phen­yl)-3-(thio­phen-3-yl)prop-1-en-3-one, C15H14O2S, (3), and 1-(4-­bromophen­yl)-3-(thio­phen-3-yl)prop-1-en-3-one, C13H9BrOS, (4), are described. The four chalcones have been synthesized by reaction of thio­phene-3-carbaldehyde with an aceto­phenone derivative in an absolute ethanol solution containing potassium hydroxide, and differ in the substituent at the para position of the phenyl ring: –OH for 1, –OCH3 for 2, –OCH2CH3 for 3 and –Br for 4. The thio­phene ring in 4 was found to be disordered over two orientations with occupancies 0.702 (4) and 0.298 (4). The configuration about the C=C bond is E. The thio­phene and phenyl rings are inclined by 4.73 (12) for 1, 12.36 (11) for 2, 17.44 (11) for 3 and 46.1 (6) and 48.6 (6)° for 4, indicating that the –OH derivative is almost planar and the –Br derivative deviates the most from planarity. However, the substituent has no real influence on the bond distances in the α,β-unsaturated carbonyl moiety. The mol­ecular packing of 1 features chain formation in the a-axis direction by O—H⋯O contacts. In the case of 2 and 3, the packing is characterized by dimer formation through C—H⋯O inter­actions. In addition, C—H⋯π(thio­phene) inter­actions in 2 and C—H⋯S(thio­phene) inter­actions in 3 contribute to the three-dimensional architecture. The presence of C—H⋯π(thio­phene) contacts in the crystal of 4 results in chain formation in the c-axis direction. The Hirshfeld surface analysis shows that for all four derivatives, the highest contribution to surface contacts arises from contacts in which H atoms are involved.

The title compound, C22H22N2O4S2, was synthesized by the reaction of 1,4,5,8-naphthalene­tetra­carb­oxy­lic dianhydride with 3-(methyl­sulfan­yl)propyl­amine. The whole mol­ecule is generated by an inversion operation of the asymmetric unit. This mol­ecule has an anti form with the terminal methyl­thio­propyl groups above and below the aromatic di­imide plane, where four intra­molecular C—H⋯O and C—H⋯S hydrogen bonds are present and the O⋯H⋯S angle is 100.8°. DFT calculations revealed slight differences between the solid state and gas phase structures. In the crystal, C—H⋯O and C—H⋯S hydrogen bonds link the mol­ecules into chains along the [2overline20] direction. adjacent chains are inter­connected by π–π inter­actions, forming a two-dimensional network parallel to the (001) plane. Each two-dimensional layer is further packed in an ABAB sequence along the c-axis direction. Hirshfeld surface analysis shows that van der Waals inter­actions make important contributions to the inter­molecular contacts. The most important contacts found in the Hirshfeld surface analysis are H⋯H (44.2%), H⋯O/O⋯H (18.2%), H⋯C/C⋯H (14.4%), and H⋯S/S⋯H (10.2%).

In the title quinoline derivative, C24H19NO3, the two benzyl rings are inclined to the quinoline ring mean plane by 74.09 (8) and 89.43 (7)°, and to each other by 63.97 (10)°. The carboxyl­ate group is twisted from the quinoline ring mean plane by 32.2 (2)°. There is a short intra­molecular C—H⋯O contact forming an S(6) ring motif. In the crystal, mol­ecules are linked by bifurcated C—H,H⋯O hydrogen bonds, forming layers parallel to the ac plane. The layers are linked by C—H⋯π inter­actions, forming a supra­molecular three-dimensional structure.

Two bis-carbamoyl­methyl­phosphine oxide compounds, namely {[(3-{[2-(di­phen­yl­phosphino­yl)ethanamido]­meth­yl}benz­yl)carbamo­yl]meth­yl}di­phenyl­phos­phine oxide, C36H34N2O4P2, (I), and diethyl [({2-[2-(di­eth­oxy­phosphino­yl)ethanamido]­eth­yl}carbamo­yl)meth­yl]phospho­nate, C14H30N2O8P2, (II), were synthesized via nucleophilic acyl substitution reactions between an ester and a primary amine. Hydrogen-bonding inter­actions are present in both crystals, but these inter­actions are intra­molecular in the case of compound (I) and inter­molecular in compound (II). Intra­molecular π–π stacking inter­actions are also present in the crystal of compound (I) with a centroid–centroid distance of 3.9479 (12) Å and a dihedral angle of 9.56 (12)°. Inter­molecular C—H⋯π inter­actions [C⋯centroid distance of 3.622 (2) Å, C—H⋯centroid angle of 146°] give rise to supra­molecular sheets that lie in the ab plane. Key geometric features for compound (I) involve a nearly planar, trans-amide group with a C—N—C—C torsion angle of 169.12 (17)°, and a torsion angle of −108.39 (15)° between the phosphine oxide phospho­rus atom and the amide nitro­gen atom. For compound (II), the electron density corresponding to the phosphoryl group was disordered, and was modeled as two parts with a 0.7387 (19):0.2613 (19) occupancy ratio. Compound (II) also boasts a trans-amide group that approaches planarity with a C—N—C—C torsion angle of −176.50 (16)°. The hydrogen bonds in this structure are inter­molecular, with a D⋯A distance of 2.883 (2) Å and a D—H⋯A angle of 175.0 (18)° between the amide hydrogen atom and the P=O oxygen atom. These non-covalent inter­actions create ribbons that run along the b-axis direction.

The title compounds, C14H10ClFN2OS (1) and C14H10BrFN2OS (2), were synthesized by two-step reactions. The dihedral angles between the aromatic rings are 31.99 (3) and 9.17 (5)° for 1 and 2, respectively. Compound 1 features an intra­molecular bifurcated N—H⋯(O,Cl) link due to the presence of the ortho-Cl atom on the benzene ring, whereas 2 features an intra­molecular N—H⋯O hydrogen bond. In the crystal of 1, inversion dimers linked by pairs of N—H⋯S hydrogen bonds generate R22(8) loops. The extended structure of 2 features the same motif but an additional weak C—H⋯S inter­action links the inversion dimers into [100] double columns. Hirshfeld surface analyses indicate that the most important contributors towards the crystal packing are H⋯H (26.6%), S⋯H/H.·S (13.8%) and Cl⋯H/H⋯Cl (9.5%) contacts for 1 and H⋯H (19.7%), C⋯H/H⋯C (14.8%) and Br⋯H/H⋯Br (12.4%) contacts for 2.

In each of the two independent mol­ecules in the asymmetric unit of the title compound, [CdI2(C18H14N4O)], the N,O,N'-tridentate N'-[(E)-(phen­yl)(pyridin-2-yl-κN)methyl­idene]pyridine-2-carbohydrazide ligand and two iodide anions form an I2N2O penta­coordination sphere, with a distorted square-pyramidal geometry, with an I atom in the apical position. Both mol­ecules feature an intra­molecular N—H⋯N hydrogen bond. In the crystal, weak aromatic π–π stacking inter­actions [centroid–centroid separation = 3.830 (2) Å] link the mol­ecules into dimers.

The asymmetric unit of the title compound, C15H21N3OS, comprises of two crystallographically independent mol­ecules (A and B). Each mol­ecule consists of a cyclo­hexane ring and a 2-hy­droxy-3-methyl­benzyl­idene ring bridged by a hydrazinecarbo­thio­amine unit. Both mol­ecules exhibit an E configuration with respect to the azomethine C=N bond. There is an intra­molecular O—H⋯N hydrogen bond in each mol­ecule forming an S(6) ring motif. The cyclo­hexane ring in each mol­ecule has a chair conformation. The benzene ring is inclined to the mean plane of the cyclo­hexane ring by 47.75 (9)° in mol­ecule A and 66.99 (9)° in mol­ecule B. The mean plane of the cyclo­hexane ring is inclined to the mean plane of the thio­urea moiety [N—C(=S)—N] by 55.69 (9) and 58.50 (8)° in mol­ecules A and B, respectively. In the crystal, the A and B mol­ecules are linked by N—H⋯S hydrogen bonds, forming `dimers'. The A mol­ecules are further linked by a C—H⋯π inter­action, hence linking the A–B units to form ribbons propagating along the b-axis direction. The conformation of a number of related cyclo­hexa­nehydrazinecarbo­thio­amides are compared to that of the title compound.

The title compound, C12H21NO7, (I), is conformationally unstable; the predominant form present in its solution is the β-pyran­ose form (74.3%), followed by the β- and α-furan­oses (12.1 and 10.2%, respectively), α-pyran­ose (3.4%), and traces of the acyclic carbohydrate tautomer. In the crystalline state, the carbohydrate part of (I) adopts the 2C5 β-pyran­ose conformation, and the amino acid portion exists as a zwitterion, with the side chain cyclo­pentane ring assuming the E9 envelope conformation. All heteroatoms are involved in hydrogen bonding that forms a system of anti­parallel infinite chains of fused R33(6) and R33(8) rings. The mol­ecule features extensive intra­molecular hydrogen bonding, which is uniquely multicentered and involves the carboxyl­ate, ammonium and carbohydrate hy­droxy groups. In contrast, the contribution of inter­molecular O⋯H/H⋯O contacts to the Hirshfeld surface is relatively low (38.4%), as compared to structures of other d-fructose-amino acids. The 1H NMR data suggest a slow rotation around the C1—C2 bond in (I), indicating that the intra­molecular heteroatom contacts survive in aqueous solution of the mol­ecule as well.

The heterobifunctional organic ligand, 3-(1,2,4-triazol-4-yl)adamantane-1-carboxyl­ate (tr-ad-COO−), was employed for the synthesis of the title silver(I) coordination polymer, {[Ag(C13H16N3O2)]·2H2O}n, crystallizing in the rare ortho­rhom­bic C2221 space group. Alternation of the double μ2-1,2,4-triazole and μ2-η2:η1-COO− (chelating, bridging mode) bridges between AgI cations supports the formation of sinusoidal coordination chains. The AgI centers possess a distorted {N2O3} square-pyramidal arrangement with τ5 = 0.30. The angular organic linkers connect the chains into a tetra­gonal framework with small channels along the c-axis direction occupied by water mol­ecules of crystallization, which are inter­linked via O—H⋯O hydrogen bonds with carboxyl­ate groups, leading to right- and left-handed helical dispositions.

1-(2-Iodo­benzo­yl)-cyclo­pent-3-ene-1-carboxyl­ates are novel substrates to construct bi­cyclo­[3.2.1]octa­nes with anti­bacterial and anti­thrombotic activities. In this context, tert-butyl 1-(2-iodo­benzo­yl)-cyclo­pent-3-ene-1-carboxyl­ate, C17H19IO3, was synthesized and structurally characterized. The 2-iodo­benzoyl group is attached to the tertiary C atom of the cyclo­pent-3-ene ring. The dihedral angle between the benzene ring and the mean plane of the envelope-type cyclo­pent-3-ene ring is 26.0 (3)°. In the crystal, pairs of C-H⋯O hydrogen bonds link the mol­ecules to form inversion dimers.

The structure of the title compound (systematic name: N-{[(2-hy­droxy­phen­yl)methyl­idene]amino}­morpholine-4-carbo­thio­amide), C12H15N3O2S, was prev­iously determined (Koo et al., 1977) using multiple-film equi-inclination Weissenberg data, but has been redetermined with higher precision to explore its conformation and the hydrogen-bonding patterns and supra­molecular inter­actions. The mol­ecular structure shows intra­molecular O—H⋯N and C—H⋯S inter­actions. The configuration of the C=N bond is E. The mol­ecule is slightly twisted about the central N—N bond. The best planes through the phenyl ring and the morpholino ring make an angle of 43.44 (17)°. In the crystal, the mol­ecules are connected into chains by N—H⋯O and C—H⋯O hydrogen bonds, which combine to generate sheets lying parallel to (002). The most prominent contribution to the surface contacts are H⋯H contacts (51.6%), as concluded from a Hirshfeld surface analysis.

The crystal structures of the disordered hemi-DMSO solvate of (E)-2-oxo-N'-(3,4,5-tri­meth­oxy­benzyl­idene)-2H-chromene-3-carbohydrazide, C20H18N2O6·0.5C2H6OS, and (E)-N'-benzyl­idene-2-oxo-2H-chromene-3-carbohydrazide, C17H12N2O3 (4: R = C6H5), are discussed. The non-hydrogen atoms in compound [4: R = (3,4,5-MeO)3C6H2)] exhibit a distinct curvature, while those in compound, (4: R = C6H5), are essential coplanar. In (4: R = C6H5), C—H⋯O and π–π intra­molecular inter­actions combine to form a three-dimensional array. A three-dimensional array is also found for the hemi-DMSO solvate of [4: R = (3,4,5-MeO)3C6H2], in which the mol­ecules of coumarin are linked by C—H⋯O and C—H⋯π inter­actions, and form tubes into which the DMSO mol­ecules are cocooned. Hirshfeld surface analyses of both compounds are reported, as are the lattice energy and inter­molecular inter­action energy calculations of compound (4: R = C6H5).

The title compound, C15H12ClNO3, consists of a 1,2-di­hydro­quinoline-4-carb­oxyl­ate unit with 2-chloro­ethyl and propynyl substituents, where the quinoline moiety is almost planar and the propynyl substituent is nearly perpendicular to its mean plane. In the crystal, the mol­ecules form zigzag stacks along the a-axis direction through slightly offset π-stacking inter­actions between inversion-related quinoline moieties which are tied together by inter­molecular C—HPrpn­yl⋯OCarbx and C—HChlethy⋯OCarbx (Prpnyl = propynyl, Carbx = carboxyl­ate and Chlethy = chloro­eth­yl) hydrogen bonds. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (29.9%), H⋯O/O⋯H (21.4%), H⋯C/C⋯ H (19.4%), H⋯Cl/Cl⋯H (16.3%) and C⋯C (8.6%) inter­actions. Hydrogen bonding and van der Waals inter­actions are the dominant inter­actions in the crystal packing. Computational chemistry indicates that in the crystal, the C—HPrpn­yl⋯OCarbx and C—HChlethy⋯OCarbx hydrogen bond energies are 67.1 and 61.7 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.

In the title compound, C27H29BrN2, the carbazole ring system is essentially planar, with an r.m.s. deviation of 0.0781 (16) Å. An intra­molecular N—H⋯N hydrogen bond forms an S(6) ring motif. One of the tert-butyl substituents shows rotational disorder over two sites with occupancies of 0.592 (3) and 0.408 (3). In the crystal, two mol­ecules are associated into an inversion dimer through a pair of C—H⋯π inter­actions. The dimers are further linked by another pair of C—H⋯π inter­actions, forming a ribbon along the c-axis direction. A C—H⋯π inter­action involving the minor disordered component and the carbazole ring system links the ribbons, generating a network sheet parallel to (100).

In the title compound, C24H31N3O2, the mean plane of the central pyrazole ring [r.m.s. deviation = 0.095 Å] makes dihedral angles of 11.93 (9) and 84.53 (8)°, respectively, with the phenyl and benzene rings. There is a short intra­molecular N—H⋯N contact, which generates an S(5) ring motif. In the crystal, pairs of N—H⋯O hydrogen bonds link inversion-related mol­ecules into dimers, generating an R22(8) ring motif. The Hirshfeld surface analysis indicates that the most significant contribution involves H⋯H contacts of 68.6%

The crystal and mol­ecular structures of the title triorganotin di­thio­carbamate, [Sn(C6H5)3(C7H14NS2)], are described. The mol­ecular geometry about the metal atom is highly distorted being based on a C3S tetra­hedron as the di­thio­carbamate ligand is asymmetrically chelating to the tin centre. The close approach of the second thione-S atom [Sn⋯S = 2.9264 (4) Å] is largely responsible for the distortion. The mol­ecular packing is almost devoid of directional inter­actions with only weak phenyl-C—H⋯C(phen­yl) inter­actions, leading to centrosymmetric dimeric aggregates, being noted. An analysis of the calculated Hirshfeld surface points to the significance of H⋯H contacts, which contribute 66.6% of all contacts to the surface, with C⋯H/H⋯C [26.8%] and S⋯H/H⋯H [6.6%] contacts making up the balance.

In the title hydrazinecarbodi­thio­ate derivative, C27H26N2O2S2, the asymmetric unit is comprised of four mol­ecules (Z = 8 and Z' = 4). The 4-meth­oxy­phenyl rings are slightly twisted away from their attached olefinic double bonds [torsion angles = 5.9 (4)–19.6 (4)°]. The azomethine double bond has an s-trans configuration relative to one of the C=C bonds and an s-cis configuration relative to the other [C=C—C= N = 147.4 (6)–175.7 (2) and 15.3 (3)–37.4 (7)°, respectively]. The torsion angles between the azomethine C=N double bond and hydrazine-1-carbodi­thio­ate moiety indicate only small deviations from planarity, with torsion angles ranging from 0.9 (3) to 6.9 (3)° and from 174.9 (3) to 179.7 (2)°, respectively. The benzyl ring and the methyl­enesulfanyl moiety are almost perpendicular to each other, as indicated by their torsion angles [range 93.7 (3)–114.6 (2)°]. In the crystal, mol­ecules are linked by C—H⋯O, N—H⋯S and C—H⋯π(ring) hydrogen-bonding inter­actions into a three-dimensional network. Structural details of related benzyl hydrazine-1-carbodi­thio­ate are surveyed and compared with those of the title compound.

The benzo­pyran ring of the title com­pound, C16H11ClN2O2, is planar [maximum deviation = 0.079 (2) Å] and is almost perpendicular to the chloro­phenyl ring [dihedral angle = 86.85 (6)°]. In the crystal, N—H⋯O, O—H⋯N, C—H⋯O and C—H⋯Cl hydrogen bonds form inter- and intra­molecular inter­actions. The DFT/B3LYP/6-311G(d,p) method was used to determine the HOMO–LUMO energy levels. The mol­ecular electrostatic potential surfaces were investigated by Hirshfeld surface analysis and two-dimensional fingerprint plots were used to analyse the inter­molecular inter­actions in the mol­ecule.

In the title com­pound, C29H22N4O3, the carbazole system forms a dihedral angle of 68.45 (3)° with the mean plane of the bi­pyridine ring system. The bi­pyridine ring system, with two meth­oxy substituents, is approximately planar (r.m.s. deviation = 0.0670 Å), with a dihedral angle of 7.91 (13)° between the planes of the two pyridine rings. Intra­molecular C—H⋯O/N hydrogen bonds may promote the planarity of the bipyridyl ring system. In the pyridyl-substituted carbazole fragment, the pyridine ring is tilted by 56.65 (4)° with respect to the mean plane of the carbazole system (r.m.s. deviation = 0.0191 Å). In the crystal, adjacent mol­ecules are connected via C—H⋯O/N hydrogen bonds and C—H⋯π inter­actions, resulting in the formation of a three-dimensional (3D) supra­molecular network. In addition, the 3D structure contains inter­molecular π–π stacking inter­actions, with centroid–centroid distances of 3.5634 (12) Å between pyridine rings. The title com­pound exhibits a high energy gap (3.48 eV) and triplet energy (2.64 eV), indicating that it could be a suitable host material in organic light-emitting diode (OLED) applications.

The asymmetric unit of the title com­pound, catena-poly[[[(perchlorato-κO)copper(II)]-μ-3-(3-carb­oxy­prop­yl)-1,5,8,12-tetra­aza-3-azonia­cyclo­tetra­decane-κ4N1,N5,N8,N12] bis­(per­chlorate)], {[Cu(C13H30N5O2)(ClO4)](ClO4)2}n, (I), consists of a macrocyclic cation, one coordinated per­chlorate anion and two per­chlorate ions as counter-anions. The metal ion is coordinated in a tetra­gonally distorted octa­hedral geometry by the four secondary N atoms of the macrocyclic ligand, the mutually trans O atoms of the per­chlorate anion and the carbonyl O atom of the protonated carb­oxy­lic acid group of a neighbouring cation. The average equatorial Cu—N bond lengths [2.01 (6) Å] are significantly shorter than the axial Cu—O bond lengths [2.379 (8) Å for carboxyl­ate and average 2.62 (7) Å for disordered per­chlorate]. The coordinated macrocyclic ligand in (I) adopts the most energetically favourable trans-III conformation with an equatorial orientation of the substituent at the protonated distal 3-position N atom in a six-membered chelate ring. The coordination of the carb­oxy­lic acid group of the cation to a neighbouring com­plex unit results in the formation of infinite chains running along the b-axis direction, which are cross­linked by N—H⋯O hydrogen bonds between the secondary amine groups of the macrocycle and O atoms of the per­chlorate counter-anions to form sheets lying parallel to the (001) plane. Additionally, the extended structure of (I) is consolidated by numerous intra- and interchain C—H⋯O contacts.

A zinc metal–organic framework, namely poly[bis­(N,N-di­ethyl­formamide)(μ4-naphthalene-2,6-di­carboxyl­ato)(μ2-naphthalene-2,6-di­carboxyl­ato)dizinc(II)], [Zn(C12H6O4)(C15H11NO)]n, built from windmill-type secondary building units and forming zigzag shaped two-dimensional stacked layers, has been solvothermally synthesized from naphthalene-2,6-di­carb­oxy­lic acid and zinc(II) acetate as the metal source in N,N-di­ethyl­formamide containing small amounts of formic acid.

The title com­pound, C24H24N2O6, consists of ethyl 2-(1,2,3,4-tetra­hydro-2-oxo­quinolin-1-yl)acetate and 4-[(2-eth­oxy-2-oxoeth­yl)(phen­yl)carbomoyl] units, where the oxo­quinoline unit is almost planar and the acetate substituent is nearly perpendicular to its mean plane. In the crystal, C—HOxqn⋯OEthx and C—HPh­yl⋯OCarbx (Oxqn = oxoquinolin, Ethx = eth­oxy, Phyl = phenyl and Carbx = carboxyl­ate) weak hydrogen bonds link the mol­ecules into a three-dimensional network sturucture. A π–π inter­action between the constituent rings of the oxo­quinoline unit, with a centroid–centroid distance of 3.675 (1) Å may further stabilize the structure. Both terminal ethyl groups are disordered over two sets of sites. The ratios of the refined occupanies are 0.821 (8):0.179 (8) and 0.651 (18):0.349 (18). The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (53.9%), H⋯O/O⋯H (28.5%) and H⋯C/C⋯H (11.8%) inter­actions. Weak inter­molecular hydrogen-bond inter­actions and van der Waals inter­actions are the dominant inter­actions in the crystal packing. Density functional theory (DFT) geometric optimized structures at the B3LYP/6-311G(d,p) level are com­pared with the experimentally determined mol­ecular structure in the solid state. The HOMO–LUMO mol­ecular orbital behaviour was elucidated to determine the energy gap.