Xray free-electron lasers (XFELs) enable experiments that would have been impractical or impossible at conventional X-ray laser facilities. Indeed, more XFEL facilities are being built and planned, with their aim to deliver larger pulse energies and higher peak brilliance. While seeking to increase the pulse power, it is quintessential to consider the maximum pulse fluence that a grazing-incidence FEL mirror can withstand. To address this issue, several studies were conducted on grazing-incidence damage by soft X-ray FEL pulses at the European XFEL facility. Boron carbide (B4C) coatings on polished silicon substrate were investigated using 1 keV photon energy, similar to the X-ray mirrors currently installed at the soft X-ray beamlines (SASE3). The purpose of this study is to compare the damage threshold of B4C and Si to determine the advantages, tolerance and limits of using B4C coatings.

An innovative dual-thickness semi-transparent beamstop designed to enhance the performance of small-angle X-ray scattering (SAXS) experiments is introduced. This design integrates two absorbers of differing thicknesses side by side into a single attenuator, known as a beamstop. Instead of completely stopping the direct beam, it attenuates it, allowing the SAXS detector to measure the transmitted beam through the sample. This approach achieves true synchronization in measuring both scattered and transmitted signals and effectively eliminates higher-order harmonic contributions when determining the transmission light intensity through the sample. This facilitates and optimizes signal detection and background subtraction. This contribution details the theoretical basis and practical implementation of this solution at the SAXS station on the 1W2A beamline at the Beijing Synchrotron Radiation Facility. It also anticipates its application at other SAXS stations, including that at the forthcoming High Energy Photon Source, providing an effective solution for high-precision SAXS experiments.

The title compound, [RuCl2(C25H22P2)2] or [RuCl2(dppm)2] (dppm = bis­(di­phenyl­phosphan­yl)methane, C25H22P2) crystallizes as two half-mol­ecules (completed by inversion symmetry) in space group Poverline{1} (Z = 2), with the RuII atoms occupying inversion centers at 0,0,0 and 1/2, 1/2, 1/2, respectively. The bidentate phosphane ligands occupy equatorial positions while the chlorido ligands complete the distorted octa­hedral coordination spheres at axial positions. The bite angles of the phosphane chelates are similar for the two mol­ecules [(P—Ru—P)avg. = 71.1°], while there are significant differences in the twisting of the methyl­ene backbone, with a distance of the methyl­ene C atom from the RuP4 plane of 0.659 (2) and 0.299 (3) Å, respectively, and also for the phenyl substituents for both mol­ecules due to variations in weak C—H⋯Cl inter­actions.

The title compound, C16H13FN2O2, was synthesized by nucleophilic substitution of the indazole N—H hydrogen atom of methyl 1H-indazole-3-carboxyl­ate with 1-(bromo­meth­yl)-4-fluoro­benzene. In the crystal, some hydrogen-bond-like inter­actions are observed.

A second crystalline modification of the title compound, C12H19N3S [common name: cis-jasmone thio­semicarbazone] was crystallized from tetra­hydro­furane at room temperature. There is one crystallographic independent mol­ecule in the asymmetric unit, showing disorder in the cis-jasmone chain [site-occupancy ratio = 0.590 (14):0.410 (14)]. The thio­semicarbazone entity is approximately planar, with the maximum deviation from the mean plane through the N/N/C/S/N atoms being 0.0463 (14) Å [r.m.s.d. = 0.0324 Å], while for the five-membered ring of the jasmone fragment, the maximum deviation from the mean plane through the carbon atoms amounts to 0.0465 (15) Å [r.m.s.d. = 0.0338 Å]. The mol­ecule is not planar due to the dihedral angle between these two fragments, which is 8.93 (1)°, and due to the sp3-hybridized carbon atoms in the jasmone fragment chain. In the crystal, the mol­ecules are connected by N—H⋯S and C—H⋯S inter­actions, with graph-set motifs R22(8) and R21(7), building mono-periodic hydrogen-bonded ribbons along [010]. A Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are H⋯H (67.8%), H⋯S/S⋯H (15.0%), H⋯C/C⋯H (8.5%) and H⋯N/N⋯H (5.6%) [only non-disordered atoms and those with the highest s.o.f. were considered]. This work reports the second crystalline modification of the cis-jasmone thio­semicarbazone structure, the first one being published recently [Orsoni et al. (2020). Int. J. Mol. Sci. 21, 8681–8697] with the crystals obtained in ethanol at 273 K.

The reaction between a racemic mixture of (R,S)-fixolide and 4-methyl­thio­semicarbazide in ethanol with a 1:1 stoichiometric ratio and catalysed with HCl, yielded the title compound, C20H31N3S [common name: (R,S)-fixolide 4-methyl­thio­semicarbazone]. There is one crystallographically independent mol­ecule in the asymmetric unit, which is disordered over the aliphatic ring [site-occupancy ratio = 0.667 (13):0.333 (13)]. The disorder includes the chiral C atom, the neighbouring methyl­ene group and the methyl H atoms of the methyl group bonded to the chiral C atom. The maximum deviations from the mean plane through the disordered aliphatic ring amount to 0.328 (6) and −0.334 (6) Å [r.m.s.d. = 0.2061 Å], and −0.3677 (12) and 0.3380 (12) Å [r.m.s.d. = 0.2198 Å] for the two different sites. Both fragments show a half-chair conformation. Additionally, the N—N—C(=S)—N entity is approximately planar, with the maximum deviation from the mean plane through the selected atoms being 0.0135 (18) Å [r.m.s.d. = 0.0100 Å]. The mol­ecule is not planar due to the dihedral angle between the thio­semicarbazone entity and the aromatic ring, which amounts to 51.8 (1)°, and due to the sp3-hybridized carbon atoms of the fixolide fragment. In the crystal, the mol­ecules are connected by H⋯S inter­actions with graph-set motif C(4), forming a mono-periodic hydrogen-bonded ribbon along [100]. The Hirshfeld surface analysis suggests that the major contributions for the crystal cohesion are [(R,S)-isomers considered separately] H⋯H (75.7%), H⋯S/S⋯H (11.6%), H⋯C/C⋯H (8.3% and H⋯N/N⋯H (4.4% for both of them).

The structure of the title compound, C9H10OTe, at 100 K has ortho­rhom­bic (P21212) symmetry with two independent mol­ecules in the asymmetric unit (Z' = 2). The mol­ecules are folded along their Te⋯O axes, with their Te–C–O planes angled at an average of 25.1° with respect to the remaining non-H atoms, which are almost coplanar (average deviation from planarity = 0.04 Å). A Hirshfeld plot shows weak inter­molecular inter­actions between the two Te atoms located in each asymmetric mol­ecule, with a Te⋯Te distance of 3.7191 (4) Å. The structure is strongly pseudosymmetric to the space group Pccn with Z' = 1. The crystal chosen for data collection was found to be was an inversion twin.

The mol­ecular structure of the solvated title salt, (C21H25N2)2[Fe2(C14H10S2)4]·2C3H7NO reveals that the anion is situated on a crystallographic inversion center in the triclinic space group Poverline{1}. The title compound crystallizes utilizing a network of weak π-stacking inter­actions of phenyl rings pertaining to the di­thiol­ene unit. Moreover, the acidic imidazolium H atoms [N—C(H)—N] display non-classical hydrogen-bonding inter­actions of the C—H⋯O type to the oxygen atoms of the N,N-dimethyl formamide solvent, and hydrogen atoms on the backbone of imidazolium rings display weak C—H⋯S inter­actions with the di­thiol­ene sulfur atoms.

The structure of the title solvated porphyrin, C56H38N8O2·C6H14, is reported. Two porphyrin mol­ecules, one ordered and one disordered n-hexane solvate mol­ecules are present in its asymmetric unit. The porphyrin macrocycle shows a characteristic saddle-shaped distortion, and the maximum deviation from the mean plane for non-hydrogen atoms is 0.48 Å. N—H⋯N, N—H⋯O, and C—H⋯O hydrogen bonds, as well as π–π inter­actions, are observed in the crystal structure.

In the paper by Oliveira et al. [IUCrData (2023), 8, x230971], there was an error in the name of the first author.

The equimolar and hydro­chloric acid-catalysed reaction between cis-jasmone and 4-methyl­thio­semicarbazide in ethano­lic solution yields the title compound, C13H21N3S (common name: cis-jasmone 4-methyl­thio­semicarbazone). Two mol­ecules with all atoms in general positions are present in the asymmetric unit. In one of them, the carbon chain is disordered [site occupancy ratio = 0.821 (3):0.179 (3)]. The thio­semicarbazone entities [N—N—C(=S)—N] are approximately planar, with the maximum deviation from the mean plane through the selected atoms being −0.0115 (16) Å (r.m.s.d. = 0.0078 Å) for the non-disordered mol­ecule and 0.0052 (14) Å (r.m.s.d. = 0.0031 Å) for the disordered one. The mol­ecules are not planar, since the jasmone groups have a chain with sp3-hybridized carbon atoms and, in addition, the thio­semicarbazone fragments are attached to the respective carbon five-membered rings and the dihedral angles between them for each mol­ecule amount to 8.9 (1) and 6.3 (1)°. In the crystal, the mol­ecules are connected through pairs of N—H⋯S and C—H⋯S inter­actions into crystallographically independent centrosymmetric dimers, in which rings of graph-set motifs R22(8) and R21(7) are observed. A Hirshfeld surface analysis indicates that the major contributions for the crystal cohesion are from H⋯H (70.6%), H⋯S/S⋯H (16.7%), H⋯C/C⋯H (7.5%) and H⋯N/N⋯H (4.9%) inter­actions [considering the two crystallographically independent mol­ecules and only the disordered atoms with the highest s.o.f. for the evaluation].

The title complex, [PdCl2(C9H13N)2], comprises a single mol­ecule in the asymmetric unit. The PdII atom is tetra­coordinated by two N atoms from two trans-aligned organic ligands and two Cl ligands, forming a square-planar metal coordination environment. The distances from the ortho-H atoms on the phenyl ring to the central PdII atom fall within the range 4.70–5.30 Å, precluding any significant intra­molecular Pd⋯H inter­actions.

In the title compound, 2C7H7N2O+·C2O42−, proton transfer from oxalic acid to the N atom of the heterocycle has occurred to form a 2:1 molecular salt. In the extended structure, N—H⋯O hydrogen bonds link the components into [100] chains, which feature R22(8) and R44(14) loops.

The manganese title complex, [Mn(C7H5N2O4)2(C7H6N2O4)2(H2O)2]·2H2O, is one of the first 4-amino 3-nitro­benzoic acid (4 A3NBA) monoligand metal complexes to be synthesized. It crystallizes in the centrosymmetric monoclinic space group P21/n with the complex mol­ecules located on inversion centers. Four 4 A3NBA ligand mol­ecules are monodentately coordinated by the Mn2+ ion through the carb­oxy­lic oxygen atoms while the other two positions of the inner coordination sphere are occupied by water mol­ecules, giving rise to a distorted octa­hedron, and two water mol­ecules are in the outer coordination sphere. There are two intra­molecular hydrogen bonds in the complex mol­ecule. The first is of the common N—H⋯O=N type, while the second is a rarely occurring very strong hydrogen bond in which a common proton is shared by two uncoordinated oxygen atoms of neighboring carboxyl­ate groups. In the crystal, an intricate system of inter­molecular hydrogen bonds links the complex mol­ecules into a three-dimensional-network.

A new square-planar palladium complex salt hydrate, (C9H12NO)2[PdCl4]·0.5H2O, has been characterized. The asymmetric unit of the complex salt comprises two [PdCl4]2− dianions, four 2-hy­droxy-2,3-di­hydro-1H-inden-1-aminium cations, each derived from (1R,2S)-(+)-1-amino­indan-2-ol, and one water mol­ecule of crystallization. In the crystal, a two-dimensional layer parallel to (001) features a number of O—H⋯O, N—H⋯O, O—H⋯Cl and N—H⋯Cl hydrogen bonds.

In the title triazole-based N-heterocyclic carbene rhodium(I) cationic complex with a tetra­fluorido­borate counter-anion, [Rh(C8H12)(C8H15N3)(C18H15P)]BF4, which crystallizes with two cations and two anions in the asymmetric unit, the Rh center has a distorted square-planar coordination geometry with expected bond distances. Several nonclassical C—H⋯F hydrogen-bonding inter­actions help to consolidate the packing. Two of the F atoms of one of the anions are disordered over adjacent sites in a 0.814 (4):0.186 (4) ratio.

In the title complex, [Ni(C19H13N5)2](CF3SO3)2·(CH3CH2)2O, the central NiII atom is sixfold coordinated by three nitro­gen atoms of each 2,6-bis­(2-benzimidazol­yl)pyridine ligand in a distorted octa­hedral geometry with two tri­fluoro­methane­sulfonate ions and a mol­ecule of diethyl ether completing the outer coordination sphere of the complex. Hydrogen bonding contributes to the organization of the asymmetric units in columns along the a axis generating a porous supra­molecular structure. The structure was refined as a two-component twin with a refined BASF value of 0.4104 (13).

In the title complex salt, [Pd(C10H8N2)(C12H12N2O2)](CF3SO3)2, the palladium(II) atom is fourfold coordinated by two chelating ligands, 2,2'-bi­pyridine and 4,4'-dimeth­oxy-2,2'-bi­pyridine, in a distorted square-planar environment. In the crystal, weak π–π stacking inter­actions between the 2,2'-bi­pyridine rings [centroid-to-centroid distances = 3.8984 (19) Å] and between the 4,4'-dimeth­oxy-2,2'-bi­pyridine rings [centroid-to-centroid distances = 3.747 (18) Å] contribute to the alignment of the complex cations in columns parallel to the b-axis direction.

In the title complex, [Ru(C10H8N2)2(C6H6N2O)(H2O)](CF3SO3)2, the central RuII atom is sixfold coordinated by two bidentate 2,2'-bi­pyridine, an isonic­otinamide ligand, and a water mol­ecule in a distorted octa­hedral environment with tri­fluoro­methane­sulfonate ions completing the outer coordination sphere of the complex. Hydrogen bonding involving the water mol­ecule and weak π–π stacking inter­actions between the pyridyl rings in adjacent mol­ecules contribute to the alignment of the complexes in columns parallel to the c axis.

The structure of the title complex, [Zn2(C2H3O2)4(C11H9N3O)2], is triclinic containing half of the mol­ecule in the asymmetric unit. Each zinc atom is coordinated to a pyridyl and oxime nitro­gen from one di-2-pyridyl ketone oxime (dpko) ligand and a third nitro­gen from the other dpko pyridyl ring. Additionally, each zinc is coordinated to two acetato anions, one of which is bidentate and the other monodentate. The uncoordinated oxygen of the monodentate acetato group is involved in a hydrogen bond with the oxime hydrogen. The packing in the crystal is assisted by weak C—H⋯O inter­actions between acetato groups and neighboring pyridyl rings.

The title compound, C14H12O4, comprises of two crystallographically independent mol­ecules in the asymmetric unit, linked via C—H⋯O inter­actions to form dimeric entities. The allylic groups are twisted out of the phenyl planes with dihedral angles varying between 7.92 (13) and 25.42 (8)°. In the crystal, the packing follows a zigzag pattern along the c-axis direction. The absolute configuration of the sample could not be determined reliably.

The title compound, C16H17BrO2S, crystallizes as the erythro (RR/SS) isomer of a pair of sulfones that were diastereomeric due to chirality of the α-carbon atoms on the sulfone sulfur atom. The structural analysis was pivotal in showing that the 1,3 elimination reactions of these compounds, which lead to substituted stilbenes, occur with inversion at each asymmetric carbon atom. In the crystal, C—H⋯Br and C—H⋯O hydrogen bonds link the mol­ecules into a tri-periodic inter­molecular network.

The central NiII atom in the title complex, [Ni(C13H25N2S2)2], is located on an inversion center and adopts a roughly square-planar coordination environment defined by two chelating N,S donor sets of two symmetry-related ligands in a trans configuration. The Ni—N and Ni—S bond lenghts are 1.9193 (14) and 2.1788 (5) Å, respectively, with a chelating N—Ni—S bond angle of 86.05 (4)°. These data are compared with those measured for similar di­thio­carbazato ligands that bear n-octyl or n-hexyl alkyl chains. Slight differences are observed with respect to the phenyl­ethyl­idene derivative where the ligands are bound cis relative to one another.

The structure of the title compound, [RuCl2(C7H10N2)2(C2H6OS)2], has monoclinic (P21/n) symmetry. The Ru—N distances of the coordination compound are influenced by the trans chloride or di­methyl­sulfoxide-κS ligands. The mol­ecular structure exhibits disorder for two of the terminal methyl groups of a dimethyl sulfoxide ligand.

The title compound, C13H10FNO2, was obtained by the reaction of 2-bromo-4-fluoro­benzoic acid with aniline. There are two independent mol­ecules, A and B, in the asymmetric unit, with slight conformational differences: the dihedral angles between the aromatic rings are 55.63 (5) and 52.65 (5)°. Both mol­ecules feature an intra­molecular N—H⋯O hydrogen bond. In the crystal, the mol­ecules are linked by pairwise O—H⋯O hydrogen bonds to form A–B acid–acid dimers and weak C—H⋯F inter­actions further connect the dimers.

The title compound, C13H10BrNO2, was obtained by the reaction of 2,5-di­bromo­benzoic acid and aniline. The mol­ecule is twisted with a dihedral angle between the aromatic rings of 45.74 (11)° and an intr­amolecular N—H⋯O hydrogen bond is seen. In the crystal, pairwise O—H⋯O hydrogen bonds generate carb­oxy­lic acid inversion dimers.

In the title compound, C26H18BrN, the dihedral angles between the anthracene ring system and the phenyl rings are 89.51 (14) and 74.03 (15)°. In the extended structure, a weak C—H⋯Br inter­action occurs, which generates [100] chains, but no significant π–π or C—H⋯π inter­actions are observed.

The title mol­ecule, C12H15NO5, is a methyl carbamate derivative obtained by reacting (R)-2-phenyl­glycinol and methyl chloro­formate, with calcium hydroxide as heterogeneous catalyst. Supra­molecular chains are formed in the [100] direction, based on N—H⋯O hydrogen bonds between the amide and carboxyl­ate groups. These chains weakly inter­act in the crystal, and the phenyl rings do not display significant π–π inter­actions.

The title compound, trans-di­bromido­tetra­kis­(5-methyl-1H-pyrazole-κN2)manganese(II), [MnBr2(C4H6N2)4] or [Mn(3-MePzH)4Br2] (1) crystallizes in the triclinic Poverline{1} space group with the cell parameters a = 7.6288 (3), b = 8.7530 (4), c = 9.3794 (4) Å and α = 90.707 (4), β = 106.138 (4), γ = 114.285 (5)°, V = 542.62 (5) Å3, T = 120 K. The asymmetric unit contains only half the mol­ecule with the manganese atom is situated on a crystallographic inversion center. The 3-MePzH ligands are present in an AABB type manner with two methyl groups pointing up and the other two down. The supra­molecular architecture is characterized by several inter­molecular C—H⋯N, N—H⋯Br, and C—H⋯π inter­actions. Earlier, a polymorphic structure of [Mn(3-MePzH)4Br2] (2) with a similar geometry and also an AABB arrangement for the pyrazole ligands was described [Reedijk et al. (1971). Inorg. Chem. 10, 2594–2599; a = 8.802 (6), b = 9.695 (5), c = 7.613 (8) Å and α = 105.12 (4), β = 114.98 (4), γ = 92.90 (3)°, V = 558.826 (5) Å3, T = 295 K]. A varying supra­molecular pattern was reported, with the structure of 1 featuring a herringbone type pattern while that of structure 2 shows a pillared network type of arrangement along the a axis. A nickel complex [Ni(3-MePzH)4Br2] isomorphic to 1 and the analogous chloro derivatives of FeII, CoII and CuII are also known.

The title compound, C16H12FN3OS, a fluorinated di­thio­carbazate imine derivative, was synthesized by the one-pot, multi-component condensation reaction of hydrazine hydrate, carbon di­sulfide, 4-fluoro­benzyl chloride and isatin. The compound demonstrates near-planarity across much of the mol­ecule in the solid state and a Z configuration for the azomethine C=N bond. The Z form is further stabilized by the presence of an intra­molecular N—H⋯O hydrogen bond. In the extended structure, mol­ecules are linked into dimers by N—H⋯O hydrogen bonds and further connected into chains along either [2overline{1}0] or [100] by weak C—H⋯S and C—H⋯F hydrogen bonds, which further link into corrugated sheets and in combination form the overall three-dimensional network.

The title compound, [Ru(C19H13N5)2](PF6)2·3C4H10O, was obtained from the reaction of Ru(bimpy)Cl3 [bimpy is 2,6-bis­(1H-benzimidazol-2-yl)pyridine] and bimpy in refluxing ethanol followed by recrystallization from diethyl ether/aceto­nitrile. At 125 K the complex has ortho­rhom­bic (Pca21) symmetry. It is remarkable that the structure is almost centrosymmetric. However, refinement in space group Pbcn leads to disorder and definitely worse results. It is of inter­est with respect to potential catalytic reduction of CO2. The structure displays N—H⋯O, N—H⋯F hydrogen bonding and significant π–π stacking and C—H⋯π stacking inter­actions.

In the title compound, C22H11N3O3S, dihedral angle between the phenyl rings on the periphery of the molecule is 8.05 (18)°. In the crystal, aromatic π–π stacking distance and short C—H⋯O contacts are observed. The maximum absorption occurs at 688 nm.

In the title salt solvate (systematic name: 8-amino-5-ethyl-6-phenyl­phenanthridin-5-ium benzoate methanol monosolvate), C21H20N3+·C6H5CO2−·CH3OH, two ethidium cations, C21H20N3+, dimerize about a twofold axis through π–π inter­actions [inter-centroid separation = 3.6137 (4) Å]. The benzoate anions are connected through hydrogen bonding with the –NH2 groups of the ethidium cations and the –OH group of the MeOH mol­ecule. The MeOH mol­ecule also accepts a hydrogen bond from the –NH2 group of the ethidium cation. The result is a one-dimensional hydrogen-bonded chain along the b-axis direction.

The title compound, [Ag(C15H9N3S2)2]ClO4·2CH3OH, is monoclinic. The AgI atom is coordinated by pyrido N atoms and is two-coordinate; however, the AgI atom has nearby O atoms that can be assumed to be weakly bonded – one from the perchlorate anion and one from the methanol solvate molecule. One of the thienyl groups on a 2,3-bis­(thio­phen-2-yl)pyrido[3,4-b]pyrazine is flipped disordered and was refined to occupancies of 68.4 (6) and 31.6 (6)%.

In the title compound, [Ni(C13H13N4S)2]·0.33CH3OH·0.67H2O, the NiII atom is coordinated by two tridentate quinoline-2-carboxaldehyde 4-ethyl­thio­semi­car­ba­zonate ligands in a distorted octa­hedral shape. At 100 K, the crystal symmetry is monoclinic (space group P21/n). A mixture of water and methanol crystallizes with the title complex, and one of the ethyl groups in the coordinating ligands is disordered over two positions, with an occupancy ratio of 58:42. There is inter­molecular hydrogen bonding between the solvent mol­ecules and the amine and thiol­ate groups in the ligands. No other significant inter­actions are present in the crystal packing.

The extraction and purification procedures, crystallization and crystal structure refinement (single-crystal X-ray data) of germacrone type II, C15H22O, are presented. The structural results are compared with a previous powder X-ray synchrotron study [Kaduk et al. (2022). Powder Diffr. 37, 98–104], revealing significant improvements in terms of accuracy and precision. Hirshfeld atom refinement (HAR), as well as Hirshfeld surface analysis, give insight into the inter­molecular inter­actions of germacrone type II.

In the title compound, {(C6H8N)[Zn2(HPO3)2(H2PO3)]}n, the constituent ZnO4, HPO3 and H2PO3 polyhedra of the inorganic component are linked into (010) sheets by Zn—O—P bonds (mean angle = 134.4°) and the layers are reinforced by O—H⋯O hydrogen bonds. The protonated templates are anchored to the inorganic sheets via bifurcated N—H⋯(O,O) hydrogen bonds.

The title compound, C22H12N2S2, crystallizes in space group P21/c with four mol­ecules in the asymmetric unit. The heterocyclic mol­ecule is quasi-planar with a dihedral angle between the phenyl rings on the periphery of the mol­ecule of 1.73 (19)°. Short H⋯S (2.92 Å) and C—H⋯π [2.836 (3) Å] contacts are observed in the crystal with shorted π–π stacking distances of 3.438 (3) Å along the b axis. Surprisingly, and unlike a closely related material, this mol­ecule readily forms large crystals by sublimation and by slow evaporation from di­chloro­methane. The maximum absorbance in the UV-Vis spectrum is at 533 nm. Emission was measured upon excitation at 533 nm with a fluorescence λmax of 658 nm and cutoff of 900 nm.

The title compound, C22H24N2O2, crystallizes in space group P21/n. The mol­ecular structure is almost planar except for a tilt of the phenyl rings. The allyl groups on both ends exhibit the trans-form and the connected N atoms show sp2 character. The mol­ecules are stacked and assembled along the c-axis direction by C—H⋯π inter­actions.

The mol­ecule of the title NCNHCS pincer N-heterocyclic carbene palladium(II) complex, [PdBr(C21H25N3S)]Br, exhibits a slightly distorted square-planar coordination at the palladium(II) atom, with the five-membered chelate ring nearly planar. The six-membered chelate ring adopts an envelope conformation. Upon chelation, the sulfur atom becomes a stereogenic centre with an RS configuration induced by the chiral carbon of the precursor imidazolium salt. There are intra­molecular C—H⋯Br—Pd hydrogen bonds in the structure. The two inter­stitial Br atoms, as the counter-anion of the structure, are both located on crystallographic twofold axes and are connected to the complex cations via C—H⋯·Br hydrogen bonds.

The title compound, C17H17BN3I, is a type of di­aza­borinane featuring substitution at the 1, 2, and 3 positions of the nitro­gen–boron six-membered heterocycle. The organic mol­ecule has a planar structure, the dihedral angle between the pyridyl ring and the fused ring system being 3.46 (4)°. In the crystal, mol­ecules are stacked in a head-to-tail manner. The iodide ion makes close contacts with three organic mol­ecules and supports the alternating stack.

The cation of the title hydrated salt, C17H17BN3+·I−·H2O, is a di­aza­borinane featuring substitution at the 1, 2, and 3 positions in the nitro­gen–boron six-membered heterocycle. The cation is approximately planar with a dihedral angle between the pyridyl ring and the di­aza­borinane ring system of 5.40 (5)°. In the crystal, the cations stack along [100] in an alternating head-to-tail manner, while the iodide ion and water mol­ecule form one-dimensional hydrogen-bonded chains beside the cation stack. The cation stacks and I−–water chains are crosslinked by N—H⋯I and N—H⋯O hydrogen bonds.

The use of acetic acid (HOAc) in a reaction between CuCl2·2H2O and secnid­azole, an active pharmaceutical ingredient useful in the treatment against a variety of anaerobic Gram-positive and Gram-negative bacteria, affords the title complex, [CuCl2(C7H11N3O3)2]. This compound was previously synthesized using ethanol as solvent, although its crystal structure was not reported [Betanzos-Lara et al. (2013). Inorg. Chim. Acta, 397, 94–100]. In the mol­ecular complex, the Cu2+ cation is situated at an inversion centre and displays a square-planar coordination environment. There is a hydrogen-bonded framework based on inter­molecular O—H⋯Cl inter­actions, characterized by H⋯Cl separations of 2.28 (4) Å and O—H⋯Cl angles of 175 (3)°. The resulting supra­molecular network is based on R22(18) ring motifs, forming chains in the [010] direction.

The structure of the title compound, C8H7IO3, at 90 K has monoclinic (P21/c) symmetry. The extended structure is layered and displays inter­molecular and intra­molecular hydrogen bonding arising from the same OH group.

In the title salt, (C8H20N)8[Mo10O34], the [Mo10O34]8− polyanion is located about an inversion centre and can be considered as a β-type octa­molybdate anion to which two additional MoO4 tetra­hedra are linked via common corners. The [Mo10O34]8− polyanions are packed in rows extending parallel to [001] and are connected to the di­butyl­ammonium counter-cations through N—H⋯O hydrogen-bonding inter­actions.

In the title compound, C26H18BrN, the central benzene ring makes dihedral angles with its adjacent anthracene ring system and pendant benzene ring of 87.49 (13) and 62.01 (17)°, respectively. The N—H moiety is sterically blocked from forming a hydrogen bond, but weak C—H⋯π inter­actions occur in the extended structure.

The title compound {systematic name: (2S)-2-aza­niumyl-3-[(2-carb­oxy­ethane)­sulfon­yl]propano­ate}, C6H11NO6S, forms enanti­opure crystals in the monoclinic space group P21 and exists as a zwitterion, with a protonated α-amino group and a deprotonated α-carboxyl group. Both the carboxyl groups and the amino group are involved in an extensive multicentered inter­molecular hydrogen-bonding scheme. In the crystal, the diperiodic network of hydrogen bonds propagates parallel to (101) and involves inter­connected heterodromic R43(10) rings. Electrostatic forces are major contributors to the structure energy, which was estimated by DFT calculations as Etotal = −333.5 kJ mol−1.

In the crystal structure of the title compound, {[Co(C11H9NSO5)(C10H9N3)]0.5C3H7NO·H2O}n or {[Co(dmtb)(dpa)]·0.5DMF·H2O}n (dmtb2– = 5-[(di­meth­yl­amino)­thioxometh­oxy]-1,3-benzene­dicarboxyl­ate and dpa = 4,4'-di­pyridyl­amine), an assembly of periodic [Co(C11H9NSO5)(C10H9N3)]n layers extending parallel to the bc plane is present. Each layer is constituted by distorted [CoO4N2] octa­hedra, which are connected through the μ2-coordination modes of both dmtb2– and dpa ligands. Occupationally disordered water and di­meth­yl­formamide (DMF) solvent mol­ecules are located in the voids of the network to which they are connected through hydrogen-bonding inter­actions.

In the crystal of the title compound, C15H16O4, the mol­ecules are connected through C—H⋯O hydrogen bonds, generating [100] chains, which are crosslinked by weak π–π stacking inter­actions.

The title compound, [Fe(C84H52N12O4)Cl], crystallizes in space group C2/c. The central FeIII cation (site symmetry 2) is coordinated in a fivefold manner, with four pyrrole N atoms of the porphyrin core in the basal sites and one Cl atom (site symmetry 2) in the apical position, which completes a slightly distorted square-pyramidal environment. The porphyrin macrocycle shows a characteristic ruffled-shape distortion and the iron atom is displaced out of the porphyrin plane by 0.42 Å with the average Fe—N distance being 2.054 (4) Å; the Fe—Cl bond length is 2.2042 (7) Å. Inter­molecular C—H⋯N and C—H⋯O hydrogen bonds occur in the crystal structure.