ALBERT

Description: In the title molecule, C20H24Br2N4, the imidazopyridine moiety is not planar as indicated by the dihedral angle of 2.0 (2)° between the constituent rings; the 4-dimethylaminophenyl ring is inclined to the mean plane of the imidazole ring by 27.4 (1)°. In the crystal, two sets of C—H...π(ring) interactions form stacks of molecules extending parallel to the a-axis direction. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (42.2%), H...C/C...H (23.1%) and H...Br/Br...H (22.3%) interactions. The optimized structure calculated using density functional theory (DFT) at the B3LYP/ 6–311 G(d,p) level is compared with the experimentally determined structure in the solid state. The calculated HOMO–LUMO energy gap is 2.3591 eV.

Description: In the title unsymmetrical tertiary amine, C24H33NO2, which arose from the ring-opening reaction of a dihydrobenzoxazine, two 2,4-dimethylphenol moieties are linked by a 6,6′-(cyclohexylazanediyl)-bis(methylene) bridge: the dihedral angle between the dimethylphenol rings is 72.45 (7)°. The cyclohexyl ring adopts a chair conformation with the exocyclic C—N bond in an equatorial orientation. One of the phenol OH groups forms an intramolecular O—H...N hydrogen bond, generating an S(6) ring, and a short intramolecular C—H...O contact is also present. In the crystal, O—H...O hydrogen bonds link the molecules into C(10) chains propagating along the [100] direction. The Hirshfeld surface analysis of the title compound confirms the presence of these intra- and intermolecular interactions. The corresponding fingerprint plots indicate that the most significant contacts in the crystal packing are H...H (76.4%), H...C/C...H (16.3%), and H...O/O...H (7.2%).

Description: The complete molecule of the title hydrazine carbodithioate derivative, C32H30N4O2S4, is generated by a crystallographic twofold axis that bisects the disulfide bond. The molecule is twisted about this bond with the C—S—S—C torsion angle of 90.70 (8)° indicating an orthogonal relationship between the symmetry-related halves of the molecule. The conformation about the imine bond [1.282 (2) Å] is E and there is limited delocalization of π-electron density over the CN2C residue as there is a twist about the N—N bond [C—N—N—C torsion angle = −166.57 (15)°]. An intramolecular hydroxyl-O—H...N(imine) hydrogen bond closes an S(6) loop. In the crystal, methylene-C—H...π(tolyl) contacts assemble molecules into a supramolecular layer propagating in the ab plane: the layers stack without directional interactions between them. The analysis of the calculated Hirshfeld surfaces confirm the importance of H...H contacts, which contribute 46.7% of all contacts followed by H...C/C...H contacts [25.5%] reflecting, in part, the C—H...π(tolyl) contacts. The calculation of the interaction energies confirm the importance of the dispersion term and the influence of the stabilizing H...H contacts in the inter-layer region.

Description: In the title compound, C18H19Cl2N3, the planes of the benzene rings subtend a dihedral angle of 77.07 (10)°. In the crystal, molecules are associated into inversion dimers via short Cl...Cl contacts [3.3763 (9) Å]. A Hirshfeld surface analysis indicates that the most important contact percentages for the different types of interactions are H...H (43.9%), Cl...H/H...Cl (22.9%), C...H/H...C (20.8%) and N...H/H...N (8.0%).

Description: The title morpholinochlorin, C46H16F20N4O3, was crystallized from hexane/methylene chloride as its 0.44 methylene chloride solvate, C46H16F20N4O3·0.44CH2Cl2. The morpholinochlorin was synthesized by stepwise oxygen insertion into a porphyrin using a `breaking and mending strategy': NaIO4-induced diol cleavage of the corresponding 2,3-dihydroxychlorin with in situ methanol-induced, acid-catalyzed intramolecular ring closure of the intermediate secochlorins bisaldehyde. Formally, one of the pyrrolic building blocks was thus replaced by a 2,3-dimethoxymorpholine moiety. Like other morpholinochlorins, the macrocycle of the title compound adopts a ruffled conformation, and the modulation of the porphyrinic π-system chromophore induces a red-shift of its optical spectrum compared to its corresponding chlorin analog. Packing in the crystal is governed by interactions involving the fluorine atoms of the pentafluorophenyl substituents, dominated by C—H...F interactions, and augmented by short fluorine...fluorine contacts, C—F...π interactions, and one severely slipped π-stacking interaction between two pentafluorophenyl rings. The solvate methylene chloride molecule is disordered over two independent positions around an inversion center with occupancies of two × 0.241 (5) and two × 0.199 (4), for a total site occupancy of 88%.

Description: The title compound, C15H15NO, is an enantiopure small molecule, which has been synthesized many times, although its crystal structure was never determined. By recrystallization from a variety of solvent mixtures (pure acetonitrile, ethanol–water, toluene–ethanol, THF–methanol), we obtained three unsolvated polymorphs, in space groups P21 and P212121. Form I is obtained from acetonitrile, without admixture of other forms, whereas forms II and III are obtained simultaneously by concomitant crystallizations from alcohol-based solvent mixtures. All forms share the same supramolecular structure, based on infinite C 1 1(4) chain motifs formed by N—H...O intermolecular hydrogen bonds, as usual for non-sterically hindered amides. However, a conformational modification of the molecular structure, related to the rotation of the phenyl rings, alters the packing of the chains in the crystal structures. The orientation of the chain axis is perpendicular and parallel to the crystallographic twofold screw axis of space group P21 in forms I and II, respectively. As for form III, the asymmetric unit contains two independent molecules forming parallel chains in space group P212121, and the crystal structure combines features of monoclinic forms I and II.

Description: The syntheses and crystal structures for the compounds tetra-μ-aqua-tetrakis{2-[azanidylene(oxido)methyl]phenolato}tetrakis(μ2-3-hydroxybenzoato)dysprosium(III)tetramanganese(III)sodium(I) N,N-dimethylacetamide decasolvate, [DyMn4Na(C7H5O3)4(C7H4NO2)4(H2O)4]·10C4H9NO or [DyIIINa(4-OHben)4{12-MCMn(III)N(shi)-4}(H2O)4]·10DMA, 1, and tetra-μ-aqua-tetrakis{2-[azanidylene(oxido)methyl]phenolato}tetrakis(μ2-3-hydroxybenzoato)dysprosium(III)tetramanganese(III)sodium(I) N,N-dimethylformamide tetrasolvate, [DyMn4Na(C7H5O3)4(C7H4NO2)4(H2O)4]·4C3H7NO or [DyIIINa(3-OHben)4{12-MCMn(III)N(shi)-4}(H2O)4]·4DMF, 2, and where MC is metallacrown, shi3− is salicylhydroximate, 3-OHben is 3-hydroxybenzoate, DMA is N,N-dimethylacetamide, 4-OHben is 4-hydroxybenzoate, and DMF is N,N-dimethylformamide, are reported. For both 1 and 2, the macrocyclic metallacrown consists of an [MnIII—N—O] ring repeat unit, and the domed metallacrown captures two ions in the central cavity: a DyIII ion on the convex side of the metallacrown and an Na+ ion the concave side. The MnIII ions are six-coordinate with an elongated tetragonally distorted octahedral geometry. Both the DyIII and Na+ ions are eight-coordinate. The DyIII ions possess a square-antiprismatic geometry, while the Na+ ions have a distorted biaugmented trigonal–prismatic geometry. Four 3-hydroxybenzoate or 4-hydroxybenzoate ligands bridge each MnIII ion to the central DyIII ion. For 1, whole-molecule disorder is observed for the main molecule, excluding only the DyIII and Na+ ions, and the occupancy ratio refined to 0.8018 (14):0.1982 (14). Three DMA molecules were refined as disordered with two in general positions by an approximate 180° rotation and the third disordered twice by general disorder as well as by an exact 180° rotation about a twofold axis that bisects it. The occupancy ratios refined to 0.496 (8):0.504 (8), 0.608 (9):0.392 (9), and 2×0.275 (7):2×0.225 (7), respectively. For 2, segments of the metallacrown are disordered including the DyIII ion, one of the Mn ions, two of the Mn-bound 4-hydroxybenzoate ligands, the Mn-bridging salicylhydroximate ligand, and portions of the remaining three shi3− ligands. The occupancy ratio for the metallacrown disorder refined to 0.849 (9):0.151 (9). Two DMF solvent molecules are also disordered, each over two orientations. The disorder ratios refined to 0.64 (3):0.36 (3) and to 0.51 (2):0.49 (2), respectively. For 2, the crystal under investigation was refined as a non-merohedric twin by a 90° rotation around the real a axis [twin ratio 0.9182 (8):0.0818 (8)].

Description: The title compounds, 2-(ferrocenylcarbonyl)benzoic acid, [Fe(C5H5)(C13H9O3)], 1, and 3-ferrocenylphthalide [systematic name: 3-ferrocenyl-2-benzofuran-1(3H)-one], [Fe(C5H5)(C13H9O2)], 2, have been synthesized and structurally characterized by single-crystal X-ray diffraction. The crystal structure of compound 1 was solved recently at room temperature [Qin, Y. (2019). CSD Communication (CCDC deposition number 1912662). CCDC, Cambridge, England]. Here we report a redetermination of its crystal structure at 90 K with improved precision by a factor of about three. The molecular structures of both compounds exhibit a typical sandwich structure. In the crystal packing of compound 1, each molecule engages in intermolecular hydrogen bonding, forming a centrosymmetric dimer with graph-set notation R 2 2 (8) and an O...O distance of 2.6073 (15) Å. There are weak C—H...O and C—H...π interactions in the crystal packing of compound 2. The phthalide moiety in 2 is oriented roughly perpendicular to the ferrocene backbone, with a dihedral angle of 77.4 (2)°.

Description: The structures of two hydroxy-thiophenone derivatives related to the antibiotic thiolactomycin are presented. These are the racemic 3-hydroxy-2,4-dimethyl-2H-thiophen-5-one, C6H8O2S, and 3-hydroxy-4-methyl-2H-thiophen-5-one, C5H6O2S. The main structural feature of both compounds is C(6) hydrogen-bonded chains formed between the OH and C=O groups. In achiral C5H6O2S, these chains propagate only by translation, corresponding to x + 1, y, z + 1. However, in contrast, for racemic C6H8O2S the hydrogen-bonded chains propagate through a −x + {3over 2}, y + {1over 2}, z operation, giving chains lying parallel to the crystallographic b-axis direction that are composed of alternate R and S enantiomers. The crystals of 3-hydroxy-4-methyl-2H-thiophen-5-one were found to be twinned by a 180° rotation about the reciprocal 001 direction. In the final refinement the twin ratio refined to 0.568 (2):0.432 (2).

Description: The asymmetric unit of the title salt, C17H21N4S+·C7H5O4 −·C3H7OH, consists of an olanzapinium cation, an independent 2,5-dihydroxybenzoate anion and a solvent isopropyl alcohol molecule. The central seven-membered heterocycle is in a boat conformation, while the piperazine ring displays a distorted chair conformation. The dihedral angle between the benzene and thiene rings flanking the diazepine ring is 52.58 (19)°. In the crystal, the anions and cations are connected by N—H...O and O—H...O hydrogen bonds, forming a three-dimensional network.

Description: The solid-state structures of the hydrofumarate salts of two N,N-dialkyltryptamines, namely N-ethyl-N-propyltryptammonium (EPT) hydrofumarate {systematic name: [2-(1H-indol-3-yl)ethyl](methyl)propylazanium 3-carboxyprop-2-enoate}, C15H23N2 +·C4H3O4 −, and N-allyl-N-methyltryptammonium (MALT) hydrofumarate {systematic name: [2-(1H-indol-3-yl)ethyl](methyl)(prop-2-en-1-yl)azanium 3-carboxyprop-2-enoate}, C14H19N2 +·C4H3O4 −, are reported. Both compounds possess a protonated tryptammonium cation, and a hydrofumarate anion in the asymmetric unit. The ethyl group of the EPT cation is modeled as a two-component disorder with 50% occupancy for each component. In the extended structure, N—H...O and O—H...O hydrogen bonds generate infinite two-dimensional networks parallel to the (001) plane for both compounds.

Description: The title compound, C15H12N2O, was synthesized by condensation reaction of 2-hydroxy-5-methylbenzaldehyde and 2-aminobenzonitrile, and crystallizes in the orthorhombic space group Pbca. The phenol ring is inclined to the benzonitrile ring by 25.65 (3)°. The configuration about the C=N bond is E, stabilized by a strong intramolecular O—H...N hydrogen bond that forms an S(6) ring motif. In the crystal, C—H...O and C—H...N interactions lead to the formation of sheets perpendicular to the a axis. C—H...π interactions, forming polymeric chains along the a-axis direction, connect these sheets into a three-dimensional network. A Hirshfeld surface analysis indicates that the most important contributions for the packing arrangement are from H...H and C...H/H...C interactions. The density functional theory (DFT) optimized structure at the B3LYP/6–311 G(d,p) level is compared with the experimentally determined molecular structure and the HOMO–LUMO energy gap is given.

Description: In the title compound, C13H9Cl2N3O2, the 2,6-dichlorophenyl ring and the nitro-substituted benzene ring form a dihedral angle of 21.16 (14)°. In the crystal, face-to-face π–π stacking interactions occur along the a-axis direction between the centroids of the 2,6-dichlorophenyl ring and the nitro-substituted benzene ring. Furthermore, these molecules show intramolecular N—H...Cl and C—H...O contacts and are linked by intermolecular N—H...O and C—H...Cl hydrogen bonds, forming pairs of hydrogen-bonded molecular layers parallel to (20overline{2}). The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H...H (23.0%), O...H/H...O (20.1%), Cl...H/H...Cl (19.0%), C...C (11.2%) and H...C/C...H (8.0%) interactions.

Description: The compound La24Ru11 (tetracosalanthanum undecaruthenium) crystallizes in a Ce24Co11-type structure. The non-centrosymmetric crystal structure (space group P63 mc) contains RuLa6 trigonal prisms, La6 octahedra and LaRu4 tetrahedra and is closely related to that of Ce23Ni7Mg4. This communication highlights the crystal-chemical similarities and points out the differences between the two structures. All of the tested crystals were inversion twins.

Description: The structures are reported for five salts formed by reactions between N-(4-fluorophenyl)piperazine and aromatic acids. In 4-(4-fluorophenyl)piperazin-1-ium 2-fluorobenzoate monohydrate, C10H14FN2 +·C7H4FO2 −·H2O, (I), the components are linked by a combination of N—H...O and O—H...O hydrogen bonds to form a chain of alternating R 4 6(12) and R 6 6(16) rings. The ionic components of 4-(4-fluorophenyl)piperazin-1-ium 2-bromobenzoate 0.353-hydrate, C10H14FN2 +·C7H4BrO2 −·0.353H2O, (II), are linked by N—H...O hydrogen bonds to form a centrosymmetric four-ion aggregate containing an R 4 4(12) motif, and these aggregates are linked into a molecular ladder by a single C—H...π(arene) hydrogen bond. 4-(4-Fluorophenyl)piperazin-1-ium 2-iodobenzoate, C10H14FN2 +·C7H4IO2 −, (III), crystallizes with Z′ = 2 in space group Poverline{1}: the four independent ions are linked by N—H...O hydrogen bonds to form a non-centrosymmetric aggregate again containing an R 4 4(12) motif, and aggregates of this type are linked into a ribbon by a combination of C—H...O and C—H...π(arene) hydrogen bonds. The anion in 4-(4-fluorophenyl)piperazin-1-ium 2,4,6-trinitrophenolate, C10H14FN2 +·C6H2N3O7 −, (IV), shows clear evidence of extensive electronic delocalization from the phenolate O atom into the adjacent ring. The ions are linked by a combination of two-centre N—H...O and three-centre N—H...(O)2 hydrogen bonds to form centrosymmetric four-ion aggregates containing three types of ring. The ions in 4-(4-fluorophenyl)piperazin-1-ium 3,5-dinitrobenzoate, C10H14FN2 +·C7H3N2O6 −, (V), are again linked by N—H...O hydrogen bonds to form centrosymmetric R 4 4(12) aggregates, which are themselves linked by a C—H...π(arene) hydrogen bond to form sheets, the stacking of which leads to the formation of narrow channels, containing disordered and/or mobile solvent entities. Comparisons are made with some related structures.

Description: The title compound, [Cu2(C5H7N2)(C4H10NO2)Cl2(C5H8N2)], is a pyrazolate aminoalcohol complex which contains two dimethylpyrazole molecules in monodentate and bidentate-bridged coordination modes and a monodeprotonated diethanolamine molecule. Both copper atoms are involved in the formation of non-planar five-membered chelate rings. One Cu atom is in a distorted tetrahedral environment formed by the pyridine nitrogen atom of the protonated dimethylpyrazole molecule, the N atom of the deprotonated bridged dimethylpyrazole, the Cl atom and the bridged O atom of the monodeprotonated diethanolamine. The second Cu atom has an intermediate environment between trigonal bipyramidal and square pyramidal, formed by the N atom of the deprotonated bridged dimethylpyrazole, the Cl atom and the N atom of the aminoalcohol, and two O atoms of the deprotonated and protonated OH groups. In the crystal, N—H...Cl hydrogen bonds link the molecules into antisymmetric chains running along the a-axis direction. Adjacent chains are connected by O—H...O hydrogen bonds involving the hydroxyl group as donor.

Description: Single crystals of Ag1.64Zn1.64Fe1.36(PO4)3 [silver zinc iron phosphate (1.64/1.64/1.36/3)] have been synthesized by a conventional solid-state reaction and structurally characterized by single-crystal X-ray diffraction. The title compound crystallizes with an alluaudite-like structure. All atoms of the structure are in general positions except for four, which reside on special positions of the space group, C2/c. The Ag+ cations reside at full occupancy on inversion centre sites and at partial occupancy (64%) on a twofold rotation axis. In this structure, the unique Fe3+ ion with one of the two Zn2+ cations are substitutionally disordered on the same general position (Wyckoff site 8f), with a respective ratio of 0.68/0.32 (occupancies were fixed so as to ensure electrical neutrality for the whole structure). The remaining O and P atoms are located in general positions. The three-dimensional framework of this structure consists of kinked chains of edge-sharing octahedra stacked parallel to [10overline{1}]. These chains are built up by a succession of [MO6] (M = Zn/Fe or Zn) units. Adjacent chains are connected by the PO4 anions, forming sheets oriented perpendicular to [010]. These interconnected sheets generate two types of channels parallel to the c axis, in which the Ag+ cations are located. The validity and adequacy of the proposed structural model of Ag1.64Zn1.64Fe1.36(PO4)3 was established by means of bond-valence-sum (BVS) and charge-distribution (CHARDI) analysis tools.

Description: Two crystal structures of chalcones, or 1,3-diarylprop-2-en-1-ones, are presented; both contain a methyl substitution on the 3-Ring, but differ on the 1-Ring, bromo versus cyano. The compounds are 3′-bromo-4-methylchalcone [systematic name: 1-(2-bromophenyl)-3-(4-methylphenyl)prop-2-en-1-one], C16H13BrO, and 3′-cyano-4-methylchalcone {systematic name: 2-[3-(4-methylphenyl)prop-2-enoyl]benzonitrile}, C17H13NO. Both chalcones meaningfully add to the large dataset of chalcone structures. The crystal structure of 3′-cyano-4-methylchalcone exhibits close contacts with the cyano nitrogen that do not appear in previously reported disubstituted cyanochalcones, namely interactions between the cyano nitrogen atom and a ring hydrogen atom as well as a methyl hydrogen atom. The structure of 3′-bromo-4-methylchalcone exhibits a type I halogen bond, similar to that found in a previously reported structure for 4-bromo-3′-methylchalcone.

Description: The title compound, C22H17NO2·C3H7NO, was synthesized by condensation of an aromatic aldehyde with a secondary amine and subsequent reduction. It was crystallized from a dimethylformamide solution as a monosolvate, C22H17NO2·C3H7NO. The aromatic molecule is non-planar with a dihedral angle between the mean planes of the aniline moiety and the methyl anthracene moiety of 81.36 (8)°. The torsion angle of the Caryl—CH2—NH—Caryl backbone is 175.9 (2)°. The crystal structure exhibits a three-dimensional supramolecular network, resulting from hydrogen-bonding interactions between the carboxylic OH group and the solvent O atom as well as between the amine functionality and the O atom of the carboxylic group and additional C—H...π interactions. Hirshfeld surface analysis was performed to quantify the intermolecular interactions.

Description: The title compound, bis(1,2-diphenyl-2-sulfanylideneethanethiolato-κ2 S,S′)(1,3,5-triaza-7-phosphaadamantane-κP)cobalt(II) dichloromethane hemisolvate, [Co(pdt)2(PTA)]·0.5C2H4Cl2 or [Co(C14H10S2)2(C6H12N3P)]·0.5C2H4Cl2, contains two phenyldithiolene (pdt) ligands and a 1,3,5-triaza-7-phosphaadamantane (PTA) ligand bound to cobalt with the solvent 1,2-dichloroethane molecule located on an inversion center. The cobalt core exhibits an approximately square-pyramidal geometry with partially reduced thienyl radical monoanionic ligands. The supramolecular network is consolidated by hydrogen-bonding interactions primarily with nitrogen, sulfur and chlorine atoms, as well as parallel displaced π-stacking of the aryl rings. The UV–vis, IR, and CV data are also consistent with monoanionic dithiolene ligands and an overall CoII oxidation state.

Description: The title compound, C23H28F3NO, is an ortho-hydroxy Schiff base compound, which adopts the enol–imine tautomeric form in the solid state. The molecular structure is not planar and the dihedral angle between the planes of the aromatic rings is 85.52 (10)°. The trifluoromethyl group shows rotational disorder over two sites, with occupancies of 0.798 (6) and 0.202 (6). An intramolecular O—H...N hydrogen bonding generates an S(6) ring motif. The crystal structure is consolidated by C—H...π interactions. The molecular structure was optimized via density functional theory (DFT) methods with the B3LYP functional and LanL2DZ basis set. The theoretical structure is in good agreement with the experimental data. The frontier orbitals and molecular electrostatic potential map were also examined by DFT computations.

Description: In the title compound, C21H15N2 +·C7H5O2 −, 2-phenyl-1H-phenanthro[9,10-d]imidazole and benzoic acid form an ion pair complex. The system is consolidated by hydrogen bonds along with π–π interactions and N—H...π interactions between the constituent units. For a better understanding of the crystal structure and intermolecular interactions, a Hirshfeld surface analysis was performed.

Description: The crystal structures of two salt crystals of 2,2-bis(4-methylphenyl)hexafluoropropane (Bmphfp) with amines, namely, dipyridinium 4,4′-(1,1,1,3,3,3-hexafluoropropane-2,2-diyl)dibenzoate 4,4′-(1,1,1,3,3,3-hexafluoropropane-2,2-diyl)dibenzoic acid, 2C5H6N+·C17H8F6O4 2−·C17H10F6O4, (1), and a monohydrated ethylenediammonium salt ethane-1,2-diaminium 4,4′-(1,1,1,3,3,3-hexafluoropropane-2,2-diyl)dibenzoate monohydrate, C2H10N2 2+·C17H8F6O4 2−·H2O, (2), are reported. Compounds 1 and 2 crystallize, respectively, in space group P21/c with Z′ = 2 and in space group Pbca with Z′ = 1. The crystals of compound 1 contain neutral and anionic Bmphfp molecules, and form a one-dimensional hydrogen-bonded chain motif. The crystals of compound 2 contain anionic Bmphfp molecules, which form a complex three-dimensional hydrogen-bonded network with the ethylenediamine and water molecules.

Description: The El Niño-Southern Oscillation (ENSO) is a mode of interannual variability in the coupled equatorial Pacific coupled atmosphere/ocean system. El Niño describes a state in which sea surface temperatures in the eastern Pacific increase and upwelling of colder, deep waters diminishes. El Niño events typically peak in boreal winter, but their strength varies irregularly on decadal timescales. There were exceptionally strong El Niño events in 1982–83, 1997–98 and 2015–16 that affected weather on a global scale. Widely publicized forecasts in 2014 predicted that the 2015–16 event would occur a year earlier. Predicting the strength of El Niño is a matter of practical concern due to its effects on hydroclimate and agriculture around the world. This study discusses the frequency and regularity of strong El Niño events in the context of chaotic dynamical systems. We discover a mechanism that limits their predictability in a conceptual ‘recharge oscillator’ model of ENSO. Weak seasonal forcing or noise in this model can induce irregular switching between an oscillatory state that has strong El Niño events and a chaotic state that lacks strong events. In this regime, the timing of strong El Niño events on decadal timescales is unpredictable.Key words: Chaotic attractor, El Niño, mode switching, unpredictability.

Description: We present a 5-Myr probabilistic stack, which we name the Prob-stack. It is constructed from 180 globally distributed benthic δ 18 O records using a profile hidden Markov model (HMM). Benthic stacks have been extensively employed to estimate ages in marine sediment cores and lead–lag relationships between paleoclimate proxies. Because this stack is probabilistic, it incorporates the variability among multiple records used in its construction and the uncertainty in alignments of records to the stack that have not been included in previous studies. It represents the uncertainty stemming from these two sources using a normal distribution with mean and variance in benthic δ 18 O at each point in the stack. In doing so, Prob-stack captures the time-varying mean and variance of benthic δ 18 O in the global ocean, which allows for better assessment of the uncertainty in records’ relative ages, such as lead–lag relationships. Algorithms are included.

Description: Background It is a common practice to use a simple model to explain the mechanisms or processes that occur in a much more complex, complete and computationally expensive model. Many such examples can be found in climate change research. Objective This paper uses two illustrative examples to show how we can quantitatively relate the mechanisms or processes observed in a simple climate model to similar mechanisms in a more complex one. Method A simple model can only explain a more complex solution’s mechanisms if outcomes are tested over a broad range of inputs. By carefully sampling the full set of inputs for both the simple and complex models, we can robustly compare the process or mechanistic outcomes, statistically, between them. Thus, by examining the similarity or differences in the relationship between the inputs and outputs. The method can reject an incorrect simple model. Results The examples are, first, analytic and numerical solutions to the heat equation and, second, the 1948 Stommel model of horizontal ocean circulation and a more complex quasi-geostrophic ocean model. We quantitatively state how similar the simple model’s mechanisms are to the mechanisms in the more complex representation. In addition, when a simple solution may be correct, we give the percentage of the variance of the complex model’s outcomes that is explained by the simple response along with an uncertainty estimate. Conclusion We successfully tested a methodology for robustly quantifying how the physics encapsulated by a simple model of a process may exhibit itself in another, more complex formulation. Suggestions are given as a guide for use of the methodology with more complex and realistic models.

Description: The title compound, [Mn(C3H7NO)4(H2O)2][Cu5(C7H4NO3)4]·C3H7NO or cis-[Mn(H2O)2(DMF)4]{Cu[12-MCCu(II)N(shi)-4]}·DMF, where MC is metallacrown, shi3− is salicylhydroximate, and DMF is N,N-dimethylformamide, crystallizes in the monoclinic space group P21/n. Two crystallographically independent metallacrown anions are present in the structure, and both anions exhibit minor main molecule disorder by an approximate (non-crystallographic) 180° rotation with occupancy ratios of 0.9010 (9) to 0.0990 (9) for one anion and 0.9497 (8) to 0.0503 (8) for the other. Each pentacopper(II) metallacrown contains four CuII ions in the MC ring and a CuII ion captured in the central cavity. Each CuII ion is four-coordinate with a square-planar geometry. The anionic {Cu[12-MCCu(II)N(shi)-4]}2− is charged-balanced by the presence of a cis-[Mn(H2O)2(DMF)4]2+ cation located in the lattice. In addition, the octahedral MnII counter-cation is hydrogen bonded to both MC anions via the coordinated water molecules of the MnII ion. The water molecules form hydrogen bonds with the phenolate and carbonyl oxygen atoms of the shi3− ligands of the MCs.

Description: The crystal structure of the title compound containing lutetium, the last element in the lanthanide series, was determined using a single crystal prepared by heating a pressed pellet of a 2:1 molar ratio mixture of Lu2O3 and Al2O3 powders in an Ar atmosphere at 2173 K for 4 h. Lu4Al2O9 is isostructural with Eu4Al2O9 and composed of Al2O7 ditetrahedra and Lu-centered six- and sevenfold oxygen polyhedra. The unit-cell volume, 787.3 (3) Å3, is the smallest among the volumes of the rare-earth (RE) aluminates, RE 4Al2O9. The crystal studied was refined as a two-component pseudo-merohedric twin.

Description: The title compound, C19H17ClN4O2, was obtained via a two-step synthesis involving the enol-mediated click Dimroth reaction of 4-azidoanisole with methyl 3-cyclopropyl-3-oxopropanoate leading to the 5-cyclopropyl-1-(4-methoxyphenyl)-1H-1,2,3-triazole-4-carboxylic acid and subsequent acid amidation with 4-chloroaniline by 1,1′-carbonyldiimidazole (CDI). It crystallizes in space group P21/n, with one molecule in the asymmetric unit. In the extended structure, two molecules arranged in a near coplanar fashion relative to the triazole ring planes are interconnected by N—H...N and C—H...N hydrogen bonds into a homodimer. The formation of dimers is a consequence of the above interaction and the edge-to-face stacking of aromatic rings, which are turned by 58.0 (3)° relative to each other. The dimers are linked by C—H...O interactions into ribbons. DFT calculations demonstrate that the frontier molecular orbitals are well separated in energy and the HOMO is largely localized on the 4-chlorophenyl amide motif while the LUMO is associated with aryltriazole grouping. A Hirshfeld surface analysis was performed to further analyse the intermolecular interactions.

Description: 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.

Description: Reaction of 2-(4,4-dimethyl-2-oxazolin-2-yl)aniline (H2-L1) with one equivalent of Na[N(SiMe3)2] in toluene afforded pale-yellow crystals of tetrameric poly[bis[μ3-2-(4,4-dimethyl-2-oxazolin-2-yl)anilinido][μ2-2-(4,4-dimethyl-2-oxazolin-2-yl)aniline]tetrasodium(I)], [Na4(C11H13N2O)4] n or [Na4(H-L1)4] n (2), in excellent yield. Subsequent reaction of [Na4(H-L1)4] n (2) with 1.33 equivalents of anhydrous YbCl3 in a 50:50 mixture of toluene–THF afforded yellow crystals of tris[2-(4,4-dimethyl-2-oxazolin-2-yl)anilinido]ytterbium(III), [Yb(C11H13N2O)3] or Yb(H-L1)3 (3) in moderate yield. Direct reaction of three equivalents of 2-(4′,4′-dimethyl-2′-oxazolinyl)aniline (H2-L1) with Yb[N(SiMe3)2]3 in toluene resulted in elimination of hexamethyldisilazane, HN(SiMe3)2, and produced Yb(H-L1)3 (3) in excellent yield. The structure of 2 consists of tetrameric Na4(H-L1)4 subunits in which each Na+ cation is bound to two H-L1 bridging bidentate ligands and these subunits are connected into a polymeric chain by two of the four oxazoline O atoms bridging to Na+ cations in the adjacent tetramer. This results in two 4-coordinate and two 5-coordinate Na+ cations within each tetrameric unit. The structure of 3 consists of a distorted octahedron where the bite angle of ligand L1 ranges between 74.72 (11) and 77.79 (11) degrees. The oxazoline (and anilide) N atoms occupy meridional sites such that for one ligand an anilide nitrogen is trans to an oxazoline nitrogen while for the other two oxazoline N atoms are trans to each other. This results in a significantly longer Yb—N(oxazoline) distance [2.468 (3) Å] for the bond trans to the anilide compared to those for the oxazoline N atoms trans to one another [2.376 (3), 2.390 (3) Å].

Description: The structures are described of two bis-chelated metal complexes of nickel(II) and copper(II) with S-n-hexyl 3-(1-phenylethylidene)dithiocarbazate Schiff bases in a cis configuration, namely, bis[S-n-hexyl 3-(1-phenylethylidene)dithiocarbazato-κ2 N 3,S]nickel(II), [Ni(C15H21N2S2)2], and bis[S-n-hexyl 3-(1-phenylethylidene)dithiocarbazato-κ2 N 3,S]copper(II), [Cu(C15H21N2S2)2]. In both complexes, the metals have distorted square-planar geometries. A search in the Cambridge Structural Database [Groom et al. (2016). Acta Cryst. B72, 171–179] for bis-chelated nickel(II) and copper(II) complexes with similar Schiff bases retrieved 55 and 36 hits for the two metals, respectively. An analysis of the geometrical parameters of complexes showing cis and trans configurations is reported and the values compared with those for the complexes described in this work.

Description: The solid-state structure of bis(1-mesityl-1H-imidazole-κN 3)diphenylboron trifluoromethanesulfonate, C36H38BN4 +·CF3SO3 − or (Ph2B(MesIm)2OTf), is reported. Bis(1-mesityl-1H-imidazole-κN 3)diphenylboron (Ph2B(MesIm)2 + ) is a bulky ligand that crystallizes in the orthorhombic space group Pbcn. The asymmetric unit contains one Ph2B(MesIm)2 + cationic ligand and one trifluoromethanesulfonate anion that balances the positive charge of the ligand. The tetrahedral geometry around the boron center is distorted as a result of the steric bulk of the phenyl groups. Weak interactions, such as π–π stacking are present in the crystal structure.

Description: In the title compound, C25H20O2, the central cyclohexenone ring adopts an envelope conformation. The mean plane of the cyclohexenone ring makes dihedral angles of 87.66 (11) and 23.76 (12)°, respectively, with the two attached phenyl rings, while it is inclined by 69.55 (11)° to the phenyl ring of the benzoyl group. In the crystal, the molecules are linked by C—H...O and C—H...π interactions, forming a three-dimensional network.

Description: The title compounds, 5-(2H-1,3-benzodioxol-5-yl)-N-cyclohexylpenta-2,4-dienamide, C18H21NO3 (I), and 5-(2H-1,3-benzodioxol-5-yl)-1-(pyrrolidin-1-yl)penta-2,4-dien-1-one C16H17NO3 (II), are derivatives of piperine, which is known as a pungent component of pepper. Their geometrical parameters are similar to those of the three polymorphs of piperine, which indicate conjugation of electrons over the length of the molecules. The extended structure of (I) features N—H...O amide hydrogen bonds, which generate C(4) [010] chains. The crystal of (II) features aromatic π–π stacking, as for two of three known piperine polymorphs.

Description: The title compound, C21H23F2NO, consists of two fluorophenyl groups and one butyl group equatorially oriented on a piperidine ring, which adopts a chair conformation. The dihedral angle between the mean planes of the phenyl rings is 72.1 (1)°. In the crystal, N—H...O and weak C—H...F interactions, which form R 2 2[14] motifs, link the molecules into infinite C(6) chains propagating along [001]. A weak C—H...π interaction is also observed. A Hirshfeld surface analysis of the crystal structure indicates that the most significant contributions to the crystal packing are from H...H (53.3%), H...C/C...H (19.1%), H...F/F...H (15.7%) and H...O/O...H (7.7%) contacts. Density functional theory geometry-optimized calculations were compared to the experimentally determined structure in the solid state and used to determine the HOMO–LUMO energy gap and compare it to the UV–vis experimental spectrum.

Description: In the title compound, C16H14Cl2FN3, the dihedral angle between the two aromatic rings is 64.12 (14)°. The crystal structure is stabilized by a short Cl...H contact, C—Cl...π and van der Waals interactions. The Hirshfeld surface analysis and two-dimensional fingerprint plots show that H...H (33.3%), Cl...H/H...Cl (22.9%) and C...H/H...C (15.5%) interactions are the most important contributors towards the crystal packing.

Description: Each of the title dis-symmetric di-Schiff base compounds, C15H12Cl2N2O2 (I) and C14H9BrCl2N2O (II), features a central azo-N—N bond connecting two imine groups, each with an E-configuration. One imine bond in each molecule connects to a 2,6-dichlorobenzene substituent while the other links a 2-hydroxyl-3-methoxy-substituted benzene ring in (I) or a 2-hydroxyl-4-bromo benzene ring in (II). Each molecule features an intramolecular hydroxyl-O—H...N(imine) hydrogen bond. The C—N—N—C torsion angles of −151.0 (3)° for (I) and 177.8 (6)° (II) indicates a significant twist in the former. The common feature of the molecular packing is the formation of supramolecular chains. In (I), the linear chains are aligned along the a-axis direction and the molecules are linked by methoxy-C—H...O(methoxy) and chlorobenzene-C—Cl...π(chlorobenzene) interactions. The chain in (II) is also aligned along the a axis but, has a zigzag topology and is sustained by Br...O [3.132 (4) Å] secondary bonding interactions. In each crystal, the chains pack without directional interactions between them. The non-covalent interactions are delineated in the study of the calculated Hirshfeld surfaces. Dispersion forces make the most significant contributions to the identified intermolecular interactions in each of (I) and (II).

Description: Two alkaline-earth coordination compounds, [Ba(C8H4N4O2)(H2O)4] n , (I), and [Sr(C8H4N4O2)(H2O)3] n , (II), from the one-pot hydrolysis transformation of benzoyl chloride and the in situ self-assembled [2 + 3] cycloaddition of nitrile are presented. These coordination compounds are prepared by reacting 4-cyanobenzoyl chloride with divalent alkaline-earth salts (BaCl2 and SrCl2) in aqueous solution under hydrothermal conditions. The mononuclear coordination compounds (I) and (II) show the same mode of coordination of the organic ligands. The cohesion of the crystalline structures is provided by hydrogen bonds and π-stacking interactions, thus forming three-dimensional supramolecular networks. The two compounds have a three-dimensional (3,6)-connected topology, and the structural differences between them is in the number of water molecules around the alkaline earth metals. Having the same emission frequencies, the compounds exhibit photoluminescence properties with a downward absorption value from (I) to (II).

Description: The asymmetric unit of the title 1:2 co-crystal, C14H14N4O2·2C7H5ClO2, comprises a half-molecule of oxalamide (4 LH2), being located about a centre of inversion, and a molecule of3-chlorobenzoic acid (3-ClBA) in a general position. From symmetry, the 4 LH2 molecule has a (+)antiperiplanar conformation with the 4-pyridyl residues lying to either side of the central, planar C2N2O2 chromophore with the dihedral angle between the core and pyridyl ring being 74.69 (11)°; intramolecular amide-N—H...O(amide) hydrogen bonds are noted. The 3-ClBA molecule exhibits a small twist as seen in the C6/CO2 dihedral angle of 8.731 (12)°. In the molecular packing, three-molecule aggregates are formed via carboxylic acid-O—H...N(pyridyl) hydrogen bonding. These are connected into a supramolecular tape along [111] through amide-N—H...O(carbonyl) hydrogen bonding. Additional points of contact between molecules include pyridyl and benzoic acid-C—H...O(amide), methylene-C—H...O(carbonyl) and C—Cl...π(pyridyl) interactions so a three-dimensional architecture results. The contributions to the calculated Hirshfeld surface are dominated by H...H (28.5%), H...O/O...H (23.2%), H...C/C...H (23.3%), H...Cl/Cl...H (10.0%) and C...Cl/C...Cl (6.2%) contacts. Computational chemistry confirms the C—Cl...π interaction is weak, and the importance of both electrostatic and dispersion terms in sustaining the molecular packing despite the strong electrostatic term provided by the carboxylic acid-O—H...N(pyridyl) hydrogen bonds.

Description: Crystal structures for a series of bis(acetylacetonato)oxovanadium(IV) complexes containing N-donor pyridyl ligands are reported, namely, bis(acetylacetonato-κ2 O,O′)oxido(pyridine-κN)vanadium(IV), [V(C5H7O2)2O(C5H5N)], 1, bis(acetylacetonato-κ2 O,O′)oxido(pyridine-4-carbonitrile-κN)vanadium(IV), [V(C5H7O2)2O(C6H4N2)], 2, and bis(acetylacetonato-κ2 O,O′)(4-methoxypyridine-κN)oxidovanadium(IV), [V(C5H7O2)2O(C6H7NO)], 3, Compounds 1–3 have the formulae VO(C5H7O2)2 L, where L = pyridine (1), 4-cyano-pyridine (2), and 4-methoxypyridine (3). Compound 1 was previously reported [Meicheng et al. (1984). Kexue Tongbao, 29, 759–764 and DaSilva, Spiazzi, Bortolotto & Burrow (2007). Acta Crystallogr., E63, m2422] and redetermined here at cryogenic temperatures. Compounds 1 and 2 as pyridine and 4-cyanopyridine adducts, respectively, crystallize as distorted octahedral structures with the oxo and pyridyl ligands trans to one another. A crystallographic twofold axis runs through the O—V—N bonds. Compound 3 containing a 4-methoxypyridine ligand crystallizes as a distorted octahedral structure with the oxo and pyridyl ligands cis to one other, removing the twofold symmetry seen in the other complexes.

Description: Single crystals of cadmium pentaoxidoditellurate(IV), CdTe2O5, were obtained as by-products in a hydrothermal reaction of Cd(NO3)2·4H2O, TeO2, H6TeO6 and NH3 (molar ratios 2:1:1:6) at 483 K for seven days. The crystals represent a different polymorph (henceforth referred to as the β-form) than the α-CdTe2O5 crystals grown from the melt, and are isotypic with hydrothermally grown ∊-CaTe2O5. The asymmetric unit of β-CdTe2O5 comprises one Cd, two Te and five O sites, all of which are located in general positions (Wyckoff position 4 e). The cadmium(II) atom is coordinated by seven oxygen atoms, forming 2 ∞[CdO6/2O1/1] (100) layers. Both tellurium sites are surrounded by four oxygen atoms with one of them being at a significantly longer distance than the other three. The resulting bisphenoidal [TeO4] units also form layers propagating parallel to (100) by sharing edges with each other. The stereochemically active 5s 2 lone pair of the TeIV atoms leads to the formation of large channels extending along [011] and smaller ones along [010]. A quantitative comparison between the crystal structures of β-CdTe2O5 and ∊-CaTe2O5 is made.

Description: The title complex, Cu(L)2 or [Cu(C15HF10O2)2], comprised of one copper ion and two fully fluorinated ligands (L −), was crystallized with 3,4-ethylenedioxythiophene (EDOT, C6H6O2S) as a guest molecule to give in a dichloromethane solution a unique co-crystal, Cu(L)2·3C6H6O2S. In the crystal, the oxygen of one guest molecule, EDOT-1, is coordinated to the metal to give an alternate linear arrangement, and the π-planes of the others, EDOT-2 and EDOT-3, interact weakly with the pentafluorophenyl groups of the complex through arene–perfluoroarene interactions. Head-to-tail columnar and head-to-head dimeric arrangements are observed for EDOT-2 and EDOT-3, respectively, in the crystal. The Hirshfeld surface analysis indicated that the most important contributions for the crystal packing are from the F...F (20.4%), F...H/H...F (24.5%) and F...C/C...F (9.6%) interactions. The density functional theory (DFT) optimized structure at the ωB97X-D 6–31G* level was compared with the experimentally determined molecular structure in the solid state.

Description: The CoII atom in the title complex, [Co(SO4)(C12H8N2)(H2O)3] (or C12H14CoN2O7S), is octahedrally coordinated within a cis-N2O4 donor set defined by the chelating N-donors of the 1,10-phenanthroline ligand, sulfate-O and three aqua-O atoms, the latter occupying an octahedral face. In the crystal, supramolecular layers lying parallel to (110) are sustained by aqua-O—H...O(sulfate) hydrogen bonding. The layers stack along the c-axis direction with the closest directional interaction between them being a weak phenanthroline-C—H...O(sulfate) contact. There are four significant types of contact contributing to the calculated Hirshfeld surface: at 44.5%, the major contribution comes from O—H...O contacts followed by H...H (28.6%), H...C/C...H (19.5%) and C...C (5.7%) contacts. The dominance of the electrostatic potential force in the molecular packing is also evident in the calculated energy frameworks. The title complex is isostructural with its manganese, zinc and cadmium containing analogues and isomeric with its mer-triaqua analogue.

Description: Three salts containing the 4-(4-fluorophenyl)piperazin-1-ium cation have been prepared and structurally characterized. In 4-(4-fluorophenyl)piperazin-1-ium 2-hydroxy-3,5-dinitrobenzoate, C10H14FN2 +·C7H3N2O7 −, (I), the anion contains an intramolecular O—H...O hydrogen bond, and it has a structure similar to that of the picrate ion. The cations and anions are linked into [001] chains of rings by a combination of two three-centre N—H...(O)2 hydrogen bonds. The anion in 4-(4-fluorophenyl)piperazin-1-ium hydrogen oxalate, C10H14FN2 +·C2HO4 −, (II), is planar, and the cations and anions are linked into (100) sheets by multiple hydrogen bonds including two-centre N—H...O, three-centre N—H...(O)2, O—H...O, C—H...O and C—H...π(arene) types. In 4-(4-fluorophenyl)piperazin-1-ium hydrogen (2R,3R)-tartrate monohydrate, C10H14FN2 +·C4H5O6 −·H2O, (III), the anion exhibits an approximate non-crystallographic twofold rotation symmetry with antiperiplanar carboxyl groups. A combination of eight hydrogen bonds, encompassing two- and three-centre N—H...O systems, O—H...O and C—H...π(arene) types, link the independent components into a three-dimensional framework. Comparisons are made with some related structures.

Description: The title compound, 2-(3-cyano-4-isobutoxyphenyl)-4-methyl-1,3-thiazole-5-carboxylic acid ethanol monosolvate, C16H16N2O3S·C2H6O, (I), displays intermolecular O—H...O and O—H...N bonds in which the carboxyl group of the febuxostat molecule and the hydroxyl group of the ethanol molecule serve as hydrogen-bond donor sites. These interactions result in a helical hydrogen-bonded chain structure. The title structure is isostructural with a previously reported methanol analogue.

Description: Similar synthetic schemes yield two different metallacrown (MC) complexes: bis(μ-3-chlorobenzoato)hexakis(dimethylformamide)tetrakis(μ4-N,2-dioxidobenzene-1-carboximidato)tetramanganese(III)disodium(I), [Mn4Na2(C7H4ClO2)2(C7H4NO3)4(C3H7NO)6] or Na2(3-chlorobenzoate)2[12-MCMn(III)N(shi)-4](DMF)6, 1, and tetra-μ-aqua-tris(μ-3-chlorobenzoato)(dimethylformamide)tetrakis(μ4-N,2-dioxidobenzene-1-carboximidato)pentamanganese(III)sodium(I) dimethylformamide tetrasolvate 0.72-hydrate, [Mn5Na(C7H4ClO2)3(C7H4NO3)4(C3H7NO)(H2O)4]·4C3H7NO·0.718H2O or MnNa(3-chlorobenzoate)3[12-MCMn(III)N(shi)-4](DMF)(H2O)4·4DMF·0.72H2O, 2, where shi3− is salicylhydroximate and DMF is N,N-dimethylformamide. Both complexes have the same framework consisting of four MnIII ions in the MC ring and four shi3− ligands, resulting in an overall square-shaped molecule. The MnIII ions are either five- or six-coordinate with elongated bond lengths in the apical or axial direction, respectively. The structure of 1 is nearly planar, and the MC binds two Na+ ions on opposite faces of the MC central cavity. The 3-chlorobenzoate anions also bind on opposite faces of the MC and form bridges between the central Na+ ions and the ring MnIII ions. For 1 the metallacrown molecule, except for the central Na+ ion, exhibits whole molecule disorder over two sets of sites. Both moieties are centrosymmetric and are related to each other by a pseudo-mirror operation with opposite sense of rotation around the Na...Na axis. The occupancy ratio of the main disorder of the metallacrown molecules and 3-chlorobenzoate anions refined to 0.9276 (9):0.0724 (9). The structure of 2 is slightly domed, and the MC binds both an MnII ion and an Na+ ion in the MC central cavity. The MnII ion is located on the convex side of the MC, while the Na+ ion binds to the concave side. Complex 2 represents the first instance of a [12-MCMn(III)N(shi)-4] molecule binding both 3d transition metal and alkali metal ions in the central cavity. In addition, three 3-chlorobenzoate anions bind on the convex side of the MC and connect the MnII ion to three of the ring MnIII ions.

Description: The sexadentate ligand 1,1,1-tris[(salicylideneamino)methyl]ethane has been reported numerous times in its triply deprotonated form coordinated to transition metals and lanthanides, yet it has been rarely employed with main-group elements, including in substituted forms. Its structures with gallium and indium are reported as solvates, namely, ({[(2,2-bis{[(2-oxidobenzylidene)amino-κ2 N,O]methyl}propyl)imino]methyl}phenololato-κ2 N,O)gallium(III) pyridine monosolvate, [Ga(C26H24N3O3)]·C5H5N, the acetonitrile 0.75-solvate, [Ga(C26H24N3O3)]·0.75C2H3N, and ({[(2,2-bis{[(2-oxidobenzylidene)amino-κ2 N,O]methyl}propyl)imino]methyl}phenololato-κ2 N,O)indium(III) dichloromethane monosolvate, [In(C26H24N3O3)]·CH2Cl2. All three metal complexes are pseudo-octahedral and each structure contains multiple weak C—H...O and/or C—H...N intermolecular hydrogen-bonding interactions. The syntheses and additional characterization in the forms of melting points, high-resolution mass spectra, infra-red (IR) spectra, and 1H and 13C NMR spectra are also reported.

Description: Single crystals of Ni3(TeO(OH)2)2(PO4)2, trinickel(II) bis[(oxidodihydoxidotellurate(IV)] bis(phosphate),were obtained by hydrothermal synthesis at 483 K, starting from NiCO3·2Ni(OH)2, TeO2 and H3PO4 in a molar ratio of 1:2:2. The crystal structure of Ni3Te2O2(PO4)2(OH)4 is isotypic with that of Co3Te2O2(PO4)2(OH)4 [Zimmermann et al. (2011). J. Solid State Chem. 184, 3080–3084]. The asymmetric unit comprises two Ni (site symmetries overline{1}, 2/m) one Te (m), one P (m), five O (three m, two 1) and one H (1) sites. The tellurium(IV) atom shows a coordination number of five, with the corresponding [TeO3(OH)2] polyhedron having a distorted square-pyramidal shape. The two NiII atoms are both octahedrally coordinated but form different structural elements: one constitutes chains made up from edge-sharing [NiO6] octahedra extending parallel to [010], and the other isolated [NiO2(OH)4] octahedra. The two kinds of nickel/oxygen octahedra are connected by the [TeO3(OH)2] pyramids and the [PO4] tetrahedra through edge- and corner-sharing into a three-dimensional framework structure with channels extending parallel to [010]. Hydrogen bonds of medium strength between the hydroxy groups and one of the phosphate O atoms consolidate the packing. A quantitative structure comparison between Ni3Te2O2(PO4)2(OH)4 and Co3Te2O2(PO4)2(OH)4 is made.

Description: The title complexes, (η4-cycloocta-1,5-diene)bis(1,3-dimethylimidazol-2-ylidene)iridium(I) iodide, [Ir(C5H8N2)2(C8H12)]I, (1) and (η4-cycloocta-1,5-diene)bis(1,3-diethylimidazol-2-ylidene)iridium(I) iodide, [Ir(C7H12N2)2(C8H12)]I, (2), were prepared using a modified literature method. After carrying out the oxidative addition of the amino acid L-proline to [Ir(COD)(IMe)2]I in water and slowly cooling the reaction to room temperature, a suitable crystal of 1 was obtained and analyzed by single-crystal X-ray diffraction at 100 K. Although this crystal structure has previously been reported in the Pbam space group, it was highly disordered and precise atomic coordinates were not calculated. A single crystal of 2 was also obtained by heating the complex in water and letting it slowly cool to room temperature. Complex 1 was found to crystallize in the monoclinic space group C2/m, while 2 crystallizes in the orthorhombic space group Pccn, both with Z = 4.

Description: Terbium oxychloride, TbOCl, was synthesized via the simple heat-treatment of TbCl3·6H2O and its structure was determined by refinement against X-ray powder diffraction data. TbOCl crystallizes with the matlockite (PbFCl) structure in the tetragonal space group P4/nmm and is composed of alternating (001) layers of (TbO) n and n Cl−. The unit-cell parameters, unit-cell volume, and density were compared to the literature data of other isostructural rare-earth oxychlorides in the same space group and showed good agreement when compared to the calculated trendlines.

Description: The title compound, C18H16N2O2, consists of perimidine and methoxyphenol units, where the tricyclic perimidine unit contains a naphthalene ring system and a non-planar C4N2 ring adopting an envelope conformation with the NCN group hinged by 47.44 (7)° with respect to the best plane of the other five atoms. In the crystal, O—HPhnl...NPrmdn and N—HPrmdn...OPhnl (Phnl = phenol and Prmdn = perimidine) hydrogen bonds link the molecules into infinite chains along the b-axis direction. Weak C—H...π interactions may further stabilize the crystal structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (49.0%), H...C/C...H (35.8%) and H...O/O...H (12.0%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, the O—HPhnl...NPrmdn and N—HPrmdn...OPhnl hydrogen-bond energies are 58.4 and 38.0 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.

Description: A 6-chloronicotinate (6-Clnic) salt of a one-dimensional cationic nickel(II) coordination polymer with 4,4′-bipyridine (4,4′-bpy), namely, catena-poly[[[tetraaquanickel(II)]-μ-4,4′-bipyridine-κ2 N:N′] bis(6-chloronicotinate) tetrahydrate], {[Ni(C10H8N2)(H2O)4](C6H3ClNO2)2·4H2O} n or {[Ni(4,4′-bpy)(H2O)4](6-Clnic)2·4H2O} n , (1), was prepared by the reaction of nickel(II) sulfate heptahydrate, 6-chloronicotinic acid and 4,4′-bipyridine in a mixture of water and ethanol. The molecular structure of 1 comprises a one-dimensional polymeric {[Ni(4,4′-bpy)(H2O)4]2+} n cation, two 6-chloronicotinate anions and four water molecules of crystallization per repeating polymeric unit. The nickel(II) ion in the polymeric cation is octahedrally coordinated by four water molecule O atoms and by two 4,4′-bipyridine N atoms in the trans position. The 4,4′-bipyridine ligands act as bridges and, thus, connect the symmetry-related nickel(II) ions into an infinite one-dimensional polymeric chain extending along the b-axis direction. In the extended structure of 1, the polymeric chains of {[Ni(4,4′-bpy)(H2O)4]2+} n , the 6-chloronicotinate anions and the water molecules of crystallization are assembled into an infinite three-dimensional hydrogen-bonded network via strong O—H...O and O—H...N hydrogen bonds, leading to the formation of the representative hydrogen-bonded ring motifs: tetrameric R 2 4(8) and R 4 4(10) loops, a dimeric R 2 2(8) loop and a pentameric R 4 5(16) loop.

Description: The title compound C4H7BrN+·NO3 − crystallizes in the monoclinic crystal system with space group P21/c. In the crystal, π-π stacking interactions and strong N—H...O and C—H...O hydrogen bonds link the cations and anions into layers parallel to the bc plane. The O...H/H...O interactions between the cation and anion are the major factor determining the crystal packing.

Description: In the title molecule, C20H21N3O3, the allyl substituent is rotated out of the plane of its attached phenyl ring [torsion angle 100.66 (15)°]. In the crystal, C—HMthphn...OMthphn (Mthphn = methoxyphenyl) hydrogen bonds lead to the formation of (100) layers that are connected into a three-dimensional network by C—H...π(ring) interactions, together with π–π stacking interactions [centroid-to-centroid distance = 3.7318 (10) Å] between parallel phenyl rings. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H...H (48.7%) and H...C/C...H (23.3%) interactions. Computational chemistry reveals that the C—HMthphn...OMthphn hydrogen bond energy is 47.1 kJ mol−1. The theoretical structure, optimized by density functional theory (DFT) at the B3LYP/ 6–311 G(d,p) level, is compared with the experimentally determined molecular structure. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

Description: The title di-substituted thiourea, C12H16N2O3S, has the hydroxylethyl and ethyl benzoate substituents bound to the same amine-N atom, and is twisted, having a (+)syn-clinal conformation with the Namine—C—C—O(hydroxyl, carbonyl) torsion angles of 49.39 (13) and 59.09 (12)°, respectively; the dihedral angle between the almost planar CN2S core and the pendent benzene ring is 69.26 (4)°. In the crystal, supramolecular layers propagating in the ac plane are formed via a combination of hydroxyl-O—H...S(thione), amine-N—H...O(hydroxyl, carbonyl) hydrogen-bonds. The layers stack along the b axis with inter-digitation of the benzene rings allowing the formation of π–π stacking [inter-centroid separation = 3.8722 (7) Å] and parallel C=O...π interactions. A computational chemistry study shows the conventional hydrogen bonding in the crystal leads to significant electrostatic stabilization but dispersion terms are also apparent, notably through the interactions involving the benzene residue.

Description: The title compound, C13H19NO8, is based on a tetra-substituted pyrrolidine ring, which has a twisted conformation about the central C—C bond; the Cm—Ca—Ca—Cme torsion angle is 38.26 (15)° [m = methylcarboxylate, a = acetyloxy and me = methylene]. While the N-bound ethylcarboxylate group occupies an equatorial position, the remaining substituents occupy axial positions. In the crystal, supramolecular double-layers are formed by weak methyl- and methylene-C—H...O(carbonyl) interactions involving all four carbonyl-O atoms. The two-dimensional arrays stack along the c axis without directional interactions between them. The Hirshfeld surface is dominated by H...H (55.7%) and H...C/C...H (37.0%) contacts; H...H contacts are noted in the inter-double-layer region. The interaction energy calculations point to the importance of the dispersion energy term in the stabilization of the crystal.

Description: The title compounds, hexakis[μ3-2-(dimethylamino)ethanolato]hexa-μ2-isopropanolato-μ4-oxido-tetradecalithium(I), [Li7(i-PrO)3(C4H10NO)3]2O (1), and {3-[(2-methoxyethyl)(methyl)amino]-1,1-dimethylpropanolato}diisopropanolsodium(I), [Na(i-PrOH)2(C8H18NO2)] (2), were crystallized in the presence of 2-propanol (i-PrOH, C3H7OH). The structure 1 has monoclinic symmetry (C2/c) and the asymmetric unit contains half of the compound. Title compound 2 has triclinic symmetry (Poverline{1}) and the asymmetric unit is half of an inversion-symmetric aggregate. Both compounds consist of an alkali metal, an aminoalkoxide and a 2-propanol compound. Furthermore, the dimeric sodium aggregate 2 is build up by hydrogen bonding through the 2-propanol and the alkoxides. Compound 1 does not exhibit hydrogen bonding, due to the fact that the 2-propanol is deprotonated. In compound 1, benzene appeared as co-crystallate, but was suppressed by solvent masking because of strong disorder. The formula mass and density do not take account of the solvent.

Description: In the title compound [Fe(bpe)(Hbpe)Au(CN)2][Au(CN)2]2·bpe·2H2O} n [where bpe = 1,2-bis(pyridin-4-yl)ethene, C12H10N2], the FeII ion is coordinated in a distorted octahedral [FeN4O2] environment by two dicyanoaurate anions, two water molecules and two partially protonated 1,2-di(4-pyridyl)ethylene molecules. Dicyanoaurate anions bridge the FeII cations, forming infinite chains, which propagate along the a-axis direction. The chains are connected via aurophilic interactions with two non-coordinated dicyanoaurate anions for each FeII ion. The polymeric chains interact with each other via π–π stacking between the guest bpe molecules and multiple hydrogen bonds.

Description: The polymeric title compound, poly[aquahemi[μ2-3,6-bis(pyrimidin-2-yl)-1,4-dihydro-1,2,4,5-tetrazine](μ3-sulfato)cadmium(II)], [Cd(SO4)(C10H8N8)0.5(H2O)] n , (I), represents an example of a three-dimensional coordination polymer resulting from the reaction of CdSO4·8/3H2O with 3,6-bis(pyrimidin-2-yl)-1,4-dihydro-1,2,4,5-tetrazine (H2bmtz, C10H8N8) under hydrothermal conditions. The CdII atom has a distorted octahedral coordination environment defined by two nitrogen atoms from one H2bmtz ligand, three oxygen atoms from three different sulfate anions, and one oxygen atom from a coordinating water molecule. The 1,4-dihydro-1,2,4,5-tetrazine ring of the H2bmtz ligand is located about an inversion center, with the NH group being equally disordered over two sites. The sulfate anion acts as a μ3-bridging ligand to connect three CdII atoms, resulting in the formation of [Cd(SO4)(H2O)] sheets propagating parallel to the bc plane. Adjacent sheets are interconnected across the H2bmtz ligands, which coordinate the CdII atoms in a bis-bidentate coordination mode, to form a three-dimensional framework structure. The framework is further stabilized by classical O—H...O hydrogen bonds involving the coordinating water molecules and the sulfate groups, and by N—H...O hydrogen bonds between the disordered tetrazine NH groups and sulfate oxygen atom, along with C—H...π and π–π stacking [centroid-to-centroid separation = 3.5954 (15) Å] interactions between parallel pyrimidine rings of the H2bmtz ligand.

Description: The title compounds, 6-(octyloxy)hexahydrofuro[3,2-b]furan-3-ol, C14H26O4, 6-(decyloxy)hexahydrofuro[3,2-b]furan-3-ol, C16H30O4, 6-(dodecyloxy)hexahydrofuro[3,2-b]furan-3-ol, C18H34O4, and 6-(tetradecyloxy)hexahydrofuro[3,2-b]furan-3-ol, C20H38O4, consist of a polar headgroup (isosorbide) and a lipophilic alkyl chain linked via an ether bridge. Isosorbide is a biobased diol, containing two fused furan rings. One intermolecular hydrogen bond connects the molecules between the free endo hydroxy group and the opposing ether oxygen of the V-shaped head group. Thus the molecule layers interlock like in a herringbone pattern parallel to the bc plane.

Description: The asymmetric unit of the title compound, catena-poly[[[(1,4,8,11-tetraazacyclotetradecane-κ4 N 1,N 4,N 8,N 11)nickel(II)]-μ-4,4′-(diphenylsilanediyl)dibenzoato-κ2 O:O′] sesquihydrate], {[Ni(C26H18O4Si)(C10H24N4)]·1.5H2O} n , consists of the halves of the centrosymmetric macrocyclic cation and the C 2-symmetric dicarboxylate dianion and of the water molecule of crystallization. The Ni2+ ion is coordinated by the four secondary N atoms of the macrocyclic ligand characterized by the most energetically favourable trans-III conformation and two mutually trans O atoms of the carboxylate, forming a slightly tetragonally elongated trans-N4O2 octahedron. The crystals are composed of parallel polymeric chains of the macrocyclic cations linked by the anions of the acid running along the [101] direction. Each polymeric chain is bonded to four neighbouring ones via water molecules providing O—H...O hydrogen bonds to the non-coordinated carboxyl O atoms to form a three-dimensional supramolecular network.

Description: The title compound DBNB, C24H20N2O6, has been crystallized and studied by X-ray diffraction, spectroscopic and computational methods. In the title molecule, which is based on a 1,4-distyryl-2,5-dimethoxybenzene core with p-nitro-substituted terminal benzene rings, the dihedral angle between mean planes of the central fragment and the terminal phenyl ring is 16.46 (6)°. The crystal packing is stabilized by π–π interactions. DFT calculations at the B3LYP/6–311 G(d,p) level of theory were used to compare the optimized structures with the experimental data. Energy parameters, including HOMO and LUMO energies, their difference, and vertical excitation and emission energies were obtained.

Description: In the central fused ring system of the title compound, C51H42O5, all of the five-membered rings are in an envelope conformation. The dihedral angle between the two benzene rings in the fused ring system is 74.66 (7)°. In the crystal, molecules are linked by C—H...π interactions, forming a layer parallel to the ab plane. Each molecule acts as a double donor as well as a double acceptor of the C—H...π interactions. Hirshfeld surface analysis and two-dimensional fingerprint plots indicate that the most important contributions to the crystal packing are from H...H (61.4%) and C...H/H...C (25.3%) contacts.

Description: The asymmetric unit of the title compound, C23H20N2OS, contains one slightly bent molecule. The naphthalene ring system and the thiazole ring are twisted with respect to each other, making a dihedral angle of 13.69 (10)°; the anisole ring is inclined to the plane of the naphthalene ring system, the dihedral angle being 14.22 (12)°. In the crystal structure, molecules are linked by C—H...π interactions, resulting in the formation of sheets parallel to (100). Within the sheets, very weak π–π stacking interactions lead to additional stabilization. Hirshfeld surface analysis and fingerprint plots reveal that the cohesion in the crystal structure is dominated by H...H (42.5%) and C...H/H...C (37.2%) contacts.

Description: The asymmetric unit of the title compound, C22H31NO3, comprises of one molecule. The molecule is not planar, with the carboxylate ester group inclined by 33.47 (4)° to the heterocyclic ring. Individual molecules are linked by aromaticC—H...Ocarbonyl hydrogen bonds into chains running parallel to [001]. Slipped π–π stacking interactions between quinoline moieties link these chains into layers extending parallel to (100). Hirshfeld surface analysis, two-dimensional fingerprint plots and molecular electrostatic potential surfaces were used to quantify the intermolecular interactions present in the crystal, indicating that the most important contributions for the crystal packing are from H...H (72%), O...H/H...O (14.5%) and C...H/H...C (5.6%) interactions.

Description: The structure of the title compound, [CrCl2(C10H24N4)][Cr(HCONH2)2(C10H24N4)][ZnCl4]2 (C10H24N4 = 1,4,8,11-tetraazacyclotetradecane, cyclam; HCONH2 = formamide, fa), has been determined from synchrotron X-ray data. The asymmetric unit contains two independent halves of the [CrCl2(cyclam)]+ and [Cr(fa)(cyclam)]3+ cations, and one tetrachloridozincate anion. In each complex cation, the CrIII ion is coordinated by the four N atoms of the cyclam ligand in the equatorial plane and two Cl ligands or two O-bonded formamide molecules in a trans axial arrangement, displaying a distorted octahedral geometry with crystallographic inversion symmetry. The Cr—N(cyclam) bond lengths are in the range 2.061 (2) to 2.074 (2) Å, while the Cr—Cl and Cr—O(fa) bond distances are 2.3194 (7) and 1.9953 (19) Å, respectively. The macrocyclic cyclam moieties adopt the centrosymmetric trans-III conformation with six- and five-membered chelate rings in chair and gauche conformations. The crystal structure is stabilized by intermolecular hydrogen bonds involving the NH or CH groups of cyclam and the NH2 group of coordinated formamide as donors, and Cl atoms of the ZnCl4 2− anion as acceptors.

Description: The condensation of 2-furoic hydrazide and 4-dimethyl aminobenzaldehyde in ethanol yielded a yellow solid formulated as the title compound, C14H15N3O2·H2O. The crystal packing is stabilized by intermolecular O(water)—H...O,N(carbohydrazide) and N—H...O(water) hydrogen bonds, which form a two-dimensional network along the bc plane. Additional C—H...O interactions link the molecules into a three-dimensional network. The dihedral angle between the mean planes of the benzene and the furan ring is 34.47 (6)°. The carbohydrazide moiety, i.e., the C=N—N—C=O fragment and the benzene ring are almost coplanar, with an angle of 6.75 (9)° between their mean planes.

Description: The title centrosymmetric NiII complex, [Ni(NCS)2(C15H22N2O2)2], crystallizes with one half molecule in the asymmetric unit of the monoclinic unit cell. The complex adopts an octahedral coordination geometry with two mutually trans benzyl-2-(heptan-4-ylidene)hydrazine-1-carboxylate ligands in the equatorial plane with the axial positions occupied by N-bound thiocyanato ligands. The overall conformation of the molecule is also affected by two, inversion-related, intramolecular C—H...O hydrogen bonds. The crystal structure features N—H...S, C—H...S and C—H...N hydrogen bonds together with C—H...π contacts that stack the complexes along the b-axis direction. The packing was further explored by Hirshfeld surface analysis. The thermal properties of the complex were also investigated by simultaneous TGA–DTA analyses.

Description: The title compound, C19H16ClNO3S, consists of chlorophenyl methylidene and dihydrobenzothiazine units linked to an acetate moiety, where the thiazine ring adopts a screw-boat conformation. In the crystal, two sets of weak C—HPh...ODbt (Ph = phenyl and Dbt = dihydrobenzothiazine) hydrogen bonds form layers of molecules parallel to the bc plane. The layers stack along the a-axis direction with intercalation of the ester chains. The crystal studied was a two component twin with a refined BASF of 0.34961 (5). The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H...H (37.5%), H...C/C...H (24.6%) and H...O/O...H (16.7%) interactions. Hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, C—HPh...ODbt hydrogen bond energies are 38.3 and 30.3 kJ mol−1. 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. Moreover, the antibacterial activity of the title compound has been evaluated against gram-positive and gram-negative bacteria.

Description: The hydrothermal synthesis and crystal structure of the title two-dimensional coordination polymer, poly[bis(μ3-3,4-diaminobenzoato-κ3 N 3,O,O′)manganese(II)], [Mn(C7H7N2O2)2] n , are described. The Mn2+ cation (site symmetry overline{1}) adopts a tetragonally elongated trans-MnN2O4 octahedral coordination geometry and the μ3-N,O,O′ ligand (bonding from both carboxylate O atoms and the meta-N atom) links the metal ions into infinite (10overline{1}) layers. The packing is consolidated by intra-layer N—H...O and inter-layer N—H...N hydrogen bonds. The structure of the title compound is compared with other complexes containing the C7H7N2O2 − anion and those of the related M(C8H8NO2)2 (M = Mn, Co, Ni, Zn) family, where C8H8NO2 − is the 3-amino-4-methylbenzoate anion.

Description: The title compounds, 6-cyclopropyl-1,3-diphenylfulvene, C21H18, [systematic name: 5-(cyclopropylmethylidene)-1,3-diphenylcyclopenta-1,3-diene], 1, and 6-(2,3-dimethoxynaphthyl)-1,3-diphenylfulvene, C30H24O2, {systematic name: 5-[(3,4-dimethoxynaphthalen-2-yl)methylidene]-1,3-diphenylcyclopenta-1,3-diene}, 2, were prepared from 1,3-diphenylcyclopentadiene, pyrrolidine, and the corresponding aldehydes in an ethanolic solution. Each structure crystallizes with one molecule per asymmetric unit and exhibits the alternating short and long bond lengths typical of fulvenes. A network of C—H...C ring interactions as well as C—H...O interactions is observed, resulting in the compact packing found in each structure.

Description: The two isomers 2′-(4-nitrobenzoyloxy)acetophenone (systematic name: 2-acetylphenyl 4-nitrobenzoate) (I) and 2′-(2-nitrobenzoyloxy)acetophenone (systematic name: 2-acetylphenyl 2-nitrobenzoate) (II), both C15H11NO5, with para and ortho positions of the nitro substituent have been crystallized and studied. It is evident that the variation in the position of the nitro group causes a significant difference in the molecular conformations: the dihedral angle between the aromatic fragments in the molecule of I is 84.80 (4)°, while that in the molecule of II is 6.12 (7)°. Diffraction analysis revealed the presence of a small amount of water in the crystal of I. DFT calculations of the molecular energy demonstrate that the ortho substituent causes a higher energy for isomer II, while crystal lattice energy calculations show that the values are almost equal for two isomers.

Description: The crystal structure of MgCO3-II has long been discussed in the literature where DFT-based model calculations predict a pressure-induced transition of the carbon atom from the sp 2 to the sp 3 type of bonding. We have now determined the crystal structure of iron-bearing MgCO3-II based on single-crystal X-ray diffraction measurements using synchrotron radiation. We laser-heated a synthetic (Mg0.85Fe0.15)CO3 single crystal at 2500 K and 98 GPa and observed the formation of a monoclinic phase with composition (Mg2.53Fe0.47)C3O9 in the space group C2/m that contains tetrahedrally coordinated carbon, where CO4 4− tetrahedra are linked by corner-sharing oxygen atoms to form three-membered C3O9 6− ring anions. The crystal structure of (Mg0.85Fe0.15)CO3 (magnesium iron carbonate) at 98 GPa and 300 K is reported here as well. In comparison with previous structure-prediction calculations and powder X-ray diffraction data, our structural data provide reliable information from experiments regarding atomic positions, bond lengths, and bond angles.

Description: The title compound, C24H30Br2N4O2, consists of a 2-(4-nitrophenyl)-4H-imidazo[4,5-b]pyridine entity with a 12-bromododecyl substituent attached to the pyridine N atom. The middle eight-carbon portion of the side chain is planar to within 0.09 (1) Å and makes a dihedral angle of 21.9 (8)° with the mean plane of the imidazolopyridine moiety, giving the molecule a V-shape. In the crystal, the imidazolopyridine units are associated through slipped π–π stacking interactions together with weak C—HPyr...ONtr and C—HBrmdcyl...ONtr (Pyr = pyridine, Ntr = nitro and Brmdcyl = bromododecyl) hydrogen bonds. The 12-bromododecyl chains overlap with each other between the stacks. The terminal –CH2Br group of the side chain shows disorder over two resolved sites in a 0.902 (3):0.098 (3) ratio. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H...H (48.1%), H...Br/Br...H (15.0%) and H...O/O...H (12.8%) interactions. The optimized molecular structure, using density functional theory at the B3LYP/ 6–311 G(d,p) level, is compared with the experimentally determined structure in the solid state. The HOMO–LUMO behaviour was elucidated to determine the energy gap.

Description: Five examples each of 3-(5-aryloxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)-1-[4-(prop-2-yn-1-yloxy)phenyl]prop-2-en-1-ones and the corresponding 1-(4-azidophenyl)-3-(5-aryloxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)prop-2-en-1-ones have been synthesized in a highly efficient manner, starting from a common source precursor, and structures have been determined for three examples of each type. In each of 3-[5-(2-chlorophenoxy)-3-methyl-1-phenyl-1H-pyrazol-4-yl]-1-[4-(prop-2-yn-1-yloxy)phenyl]prop-2-en-1-one, C28H21ClN2O3, (Ib), the isomeric 3-[5-(2-chlorophenoxy)-3-methyl-1-phenyl-1H-pyrazol-4-yl]-1-[4-(prop-2-yn-1-yloxy)phenyl]prop-2-en-1-one, (Ic), and 3-[3-methyl-5-(naphthalen-2-yloxy)-1-phenyl-1H-pyrazol-4-yl]-1-[4-(prop-2-ynyloxy)phenyl]prop-2-en-1-one, C32H24N2O3, (Ie), the molecules are linked into chains of rings, formed by two independent C—H...O hydrogen bonds in (Ib) and by a combination of C—H...O and C—H...π(arene) hydrogen bonds in each of (Ic) and (Ie). There are no direction-specific intermolecular interactions in the structure of 1-(4-azidophenyl)-3-[3-methyl-5-(2-methylphenoxy)-1-phenyl-1H-pyrazol-4-yl]prop-2-en-1-one, C26H21N5O2, (IIa). In 1-(4-azidophenyl)-3-[5-(2,4-dichlorophenoxy)-3-methyl-1-phenyl-1H-pyrazol-4-yl]prop-2-en-1-one, C25H17Cl2N5O2, (IId), the dichlorophenyl group is disordered over two sets of atomic sites having occupancies 0.55 (4) and 0.45 (4), and the molecules are linked by a single C—H...O hydrogen bond to form cyclic, centrosymmetric R 2 2(20) dimers. Similar dimers are formed in 1-(4-azidophenyl)-3-[3-methyl-5-(naphthalen-2-yloxy)-1-phenyl-1H-pyrazol-4-yl]prop-2-en-1-one, C29H21N5O2, (IIe), but here the dimers are linked into a chain of rings by two independent C—H..π(arene) hydrogen bonds. Comparisons are made between the molecular conformations within both series of compounds.

Description: The X-ray crystal structure of the title phthalazin-1-one derivative, C17H16N2O3S {systematic name: 2-[(2,4,6-trimethylbenzene)sulfonyl]-1,2-dihydrophthalazin-1-one}, features a tetrahedral sulfoxide-S atom, connected to phthalazin-1-one and mesityl residues. The dihedral angle [83.26 (4)°] between the organic substituents is consistent with the molecule having the shape of the letter V. In the crystal, phthalazinone-C6-C—H...O(sulfoxide) and π(phthalazinone-N2C4)–π(phthalazinone-C6) stacking [inter-centroid distance = 3.5474 (9) Å] contacts lead to a linear supramolecular tape along the a-axis direction; tapes assemble without directional interactions between them. The analysis of the calculated Hirshfeld surfaces confirm the importance of the C—H...O and π-stacking interactions but, also H...H and C—H...C contacts. The calculation of the interaction energies indicate the importance of dispersion terms with the greatest energies calculated for the C—H...O and π-stacking interactions.

Description: N-[(Z)-2-(2H-1,3,2-Benzodioxaborol-2-yl)-2-phenylethenyl]-N-(propan-2-yl)aniline, C23H22BNO2, contains a C=C bond that is conjugated with a donor and an acceptor group. An analysis that included similar push–pull olefins revealed that bond lengths in their B—C=C—N core units correlate with the perceived acceptor and donor strength of the groups. The two phenyl groups in the molecule are rotated with respect to the plane that contains the BCCN atoms, and are close enough for significant π-stacking. Definite characterization of the title compound demonstrates, for the first time in a reliable way, that hydroboration of ynamines with borandiol esters is feasible. Compared to olefin hydroboration with borane, the ynamine substrate is activated enough to undergo reaction with the less active hydroboration reagent catecholborane.

Description: In the first reported crystal structure involving the potential ligand N,N′,N′′-tris(pyridin-2-yl)benzene-1,3,5-tricarboxamide, C24H18N6O3, intermolecular N—H...O hydrogen bonds link the molecules via their amide groups into slanted ladder-like chains, in which the uprights of the ladder are formed by the hydrogen-bonding interactions and the benzene ring cores of the molecules act as the rungs of the ladder. Only two of the three amide groups in the molecule are involved in hydrogen bonding and this influences the degree of out-of-plane twisting at each amide group, with the twist being more significant for those amide groups participating in hydrogen bonds.

Description: The title compound, C18H16N2O3S, was synthesized by reaction of 2-mercapto-3-phenylquinazolin-4(3H)-one with ethyl chloroacetate. The quinazoline ring forms a dihedral angle of 86.83 (5)° with the phenyl ring. The terminal methyl group is disordered by a rotation of about 60° in a 0.531 (13): 0.469 (13) ratio. In the crystal, C—H...O hydrogen-bonding interactions result in the formation of columns running in the [010] direction. Two parallel columns further interact by C—H...O hydrogen bonds. The most important contributions to the surface contacts are from H...H (48.4%), C...H/H...C (21.5%) and O...H/H...O (18.7%) interactions, as concluded from a Hirshfeld analysis.

Description: Single crystals of SrFe1.40V0.60O4, strontium tetraoxidodi[ferrate(III)/vanadate(III)], have been obtained as a side product in the course of sinter experiments aimed at the synthesis of double perovskites in the system SrO–Fe2O3–V2O5. The crystal structure can be characterized by layers of six-membered rings of TO4-tetrahedra (T: FeIII, VIII) perpendicular to [100]. Stacking of the layers along [100] results in a three-dimensional framework enclosing tunnel-like cavities in which SrII cations are incorporated for charge compensation. The sequence of directedness of up (U) and down (D) pointing vertices of neighboring tetrahedra in a single six-membered ring is UUUDDD. The topology of the tetrahedral framework belongs to the zeolite-type ABW.

Description: In small-molecule single-crystal structure determination, we now have at our disposal an inspiring range of fantastic diffractometers with better, brighter sources, and faster, more sensitive detectors. Faster and more powerful computers provide integrated tools and software with impressive graphical user interfaces. Yet these tools can lead to the temptation not to check the work thoroughly and one can too easily overlook tell-tale signs that something might be amiss in a structure determination; validation with checkCIF is not always revealing. This article aims to encourage practitioners, young and seasoned, by enhancing their structure-determination toolboxes with a selection of tips and tricks on recognizing and handling aspects that one should constantly be aware of. Topics include a pitfall when setting up data collections, the usefulness of reciprocal lattice layer images, processing twinned data, tips for disorder modelling and the use of restraints, ensuring hydrogen atoms are added to a model correctly, validation beyond checkCIF, and the derivation and interpretation of the final results.

Description: The new copper(II) complex, namely, di-μ-chlorido-bis{chlorido[methyl(pyridin-2-ylmethylidene)amine-κ2 N,N′]copper(II)}, [Cu2Cl4(C7H8N2)2], (I), with the ligand 2-pyridylmethyl-N-methylimine (L, a product of Schiff base condensation between methylamine and 2-pyridinecarbaldehyde) is built of discrete centrosymmetric dimers. The coordination about the CuII ion can be described as distorted square pyramidal. The base of the pyramid consists of two nitrogen atoms from the bidentate chelate L [Cu—N = 2.0241 (9), 2.0374 (8) Å] and two chlorine atoms [Cu—Cl = 2.2500 (3), 2.2835 (3) Å]. The apical position is occupied by another Cl atom with the apical bond being significantly elongated at 2.6112 (3) Å. The trans angles of the base are 155.16 (3) and 173.79 (2)°. The Cu...Cu separation in the dimer is 3.4346 (3) Å. In the crystal structure, the loosely packed dimers are arranged in stacks propagating along the a axis. The X-band polycrystalline 77 K EPR spectrum of (I) demonstrates a typical axial pattern characteristic of mononuclear CuII complexes. Compound (I) is redox active and shows a cyclic voltammetric response with E 1/2 = −0.037 V versus silver–silver chloride electrode (SSCE) assignable to the reduction peak of CuII/CuI in methanol as solvent.

Description: The crystal structure of vanthoffite {hexasodium magnesium tetrakis[sulfate(VI)]}, Na6Mg(SO4)4, was solved in the year 1964 on a synthetic sample [Fischer & Hellner (1964). Acta Cryst. 17, 1613]. Here we report a redetermination of its crystal structure on a mineral sample with improved precision. It was refined in the space group P21/c from a crystal originating from Surtsey, Iceland. The unique Mg (site symmetry overline{1}) and the two S atoms are in usual, only slightly distorted octahedral and tetrahedral coordinations, respectively. The three independent Na atoms are in a distorted octahedral coordination (1×) and distorted 7-coordinations intermediate between a `split octahedron' and a pentagonal bipyramid (2×). [MgO6] coordination polyhedra interchange with one half of the sulfate tetrahedra in chains forming a (100) meshed layer, with dimers formed by edge-sharing [NaO7] polyhedra filling the interchain spaces. The other [NaO7] polyhedra are organized in a parallel layer formed by [010] and [001] chains united through edge sharing and bonds to the remaining half of sulfate groups and to [NaO6] octahedra. The two types of layers interconnect through tight bonding, which explains the lack of morphological characteristics typical of layered structures.

Description: In the structure of the title salt, (C7H12N6)[VOF5], second-order Jahn–Teller distortion of the coordination octahedra around V ions is reflected by coexistence of short V—O bonds [1.5767 (12) Å] and trans-positioned long V—F bonds [2.0981 (9) Å], with four equatorial V—F distances being intermediate in magnitude [1.7977 (9)–1.8913 (9) Å]. Hydrogen bonding of the anions is restricted to F-atom acceptors only, with particularly strong N–H...F interactions [N...F = 2.5072 (15) Å] established by axial and cis-positioned equatorial F atoms. Hirshfeld surface analysis indicates that the most important interactions are overwhelmingly H...F/F...H, accounting for 74.4 and 36.8% of the contacts for the individual anions and cations, respectively. Weak CH...F and CH...N bonds are essential for generation of three-dimensional structure.

Description: The cationic complex in the title compound, [Ir(C9H7N2)2(C12H8N2)]PF6, comprises two phenylpyrazole (ppz) cyclometallating ligands and one 1,10-phenanthroline (phen) ancillary ligand. The asymmetric unit consists of one [Ir(ppz)2(phen)]+ cation and one [PF6]− counter-ion. The central IrIII ion is six-coordinated by two N atoms and two C atoms from the two ppz ligands as well as by two N atoms from the phen ligand within a distorted octahedral C2N4 coordination set. In the crystal structure, the [Ir(ppz)2(phen)]+ cations and PF6 − counter-ions are connected with each other through weak intermolecular C—H...F hydrogen bonds. Additional C—H...π interactions between the rings of neighbouring cations consolidate the three-dimensional network. Electron density associated with additional disordered solvent molecules inside cavities of the structure was removed with the SQUEEZE procedure in PLATON [Spek (2015). Acta Cryst. C71, 9–18]. The given chemical formula and other crystal data do not take into account the unknown solvent molecule(s). The title compound has a different space-group symmetry (C2/c) from its solvatomorph (P21/c) comprising 1.5CH2Cl2 solvent molecules per ion pair.

Description: The title compound, C14H16, exhibits exceptionally weak intermolecular C—H...π hydrogen bonding of the ethynyl groups, with the corresponding H...π separations [2.91 (2) and 3.12 (2) Å] exceeding normal vdW distances. This bonding complements distal contacts of the CH (aliphatic)...π type [H...π = 3.12 (2)–3.14 (2) Å] to sustain supramolecular layers. Hirshfeld surface analysis of the title compound suggests a relatively limited significance of the C...H/H...C contacts to the crystal packing (24.6%) and a major contribution from H...H contacts accounting 74.9% to the entire surface.

Description: The asymmetric unit of the title compound, C17H14N2O, contains two independent molecules each consisting of perimidine and phenol units. The tricyclic perimidine units contain naphthalene ring systems and non-planar C4N2 rings adopting envelope conformations with the C atoms of the NCN groups hinged by 44.11 (7) and 48.50 (6)° with respect to the best planes of the other five atoms. Intramolecular O—H...N hydrogen bonds may help to consolidate the molecular conformations. The two independent molecules are linked through an N—H...O hydrogen bond. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (52.9%) and H...C/C...H (39.5%) 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.

Description: In the title co-crystal, C22H24ClFN4O3·C9H16O4, gefitinib (GTB; systematic name: quinazolin-4-amine) co-crystallizes with azelaic acid (AA; systematic name: nonanedioic acid). The co-crystal has the monoclinic P21/n centrosymmetric space group, containing one molecule each of GTB and AA in the asymmetric unit. A structure overlay of the GTB molecule in the co-crystal with that of its most stable polymorph revealed a significant difference in the conformation of the morpholine moiety. The significant deviation in the conformation of one of the acidic groups of azelaic acid from its usual linear chain structure could be due to the encapsulation of one acidic group in the pocket formed between the two pincers of GTB namely, the morpholine and phenyl moieties. Both GTB and AA molecules form N—H...O, O—H...N, C—H...O hydrogen bonds with C—H...F close contacts along with off-stacked aromatic π–π interactions between the GTB molecules.

Description: Two potentially bioactive fragments, namely a tricyclic quinazoline derivative with an exocyclic alkene moiety and a substituted isoquinoline, are coupled to give 3-{[6,7-dimethoxy-1-(4-nitrophenyl)-1,2,3,4-tetrahydroisoquinolin-2-yl]methylidene}-1,2,3,9-tetrahydropyrrolo[2,1-b]quinazolin-9-one. The target product crystallizes as a methanol solvate, C29H26N4O5·CH4O, and is E configured. The alternative Z isomer would necessarily imply either considerable twist about the central double bond or very unfavourable intramolecular contacts between sterically more demanding substituents. The main residue and the co-crystallized solvent molecule aggregate to discrete pairs via a classical O—H...O hydrogen bond with a distance of 2.8581 (7) Å between the methanol OH donor and the quinazolinone O=C acceptor.

Description: Ferrocyanides with general formula A I xB II y [Fe(CN)6], where A and B are cations, are thought to accept many substitutions on the A and B positions. In this communication, the synthesis and crystal structure of Cs2Sr[Fe(CN)6] are reported. The latter was obtained from K2Ba[Fe(CN)6] particles, put in contact with caesium and strontium ions. Hence, a simultaneous ion-exchange mechanism (Cs for K, Sr for Ba) occurs to yield Cs2Sr[Fe(CN)6]. The synthesis protocol shows that K2BaFe(CN)6 particles can be used for the simultaneous trapping of radioactive caesium and strontium nuclides in water streams. Cs2Sr[Fe(CN)6] adopts the cryolite structure type and is isotypic with the known compound Cs2Na[Mn(CN)6] [dicaesium sodium hexacyanidomanganate(III)]. The octahedrally coordinated Sr and Fe sites both are located on inversion centres, and the eightfold-coordinated Cs site on a general position.

Description: The title compound, C22H25NOS, consists of methylbenzylidene and benzothiazine units linked to a hexyl moiety, where the thiazine ring adopts a screw-boat conformation. In the crystal, inversion dimers are formed by weak C—HMthn...OBnzthz hydrogen bonds and are linked into chains extending along the a-axis direction by weak C—HBnz...OBnzthz (Bnz = benzene, Bnzthz = benzothiazine and Mthn = methine) hydrogen bonds. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (59.2%) and H...C/C...H (27.9%) 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—HBnz...OBnzthz and C—HMthn...OBnzthz hydrogen-bond energies are 75.3 and 56.5 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. Moreover, the antibacterial activity of the title compound was evaluated against gram-positive and gram-negative bacteria.

Description: The title compound, C19H17NO5, obtained by ether bond formation between the reagents, crystallizes in the monoclinic space group P21/c. The compound is non-planar, subtending a dihedral angle of 82.38 (4)° between the plane of hydroxy isophthalate-based ester and that of the benzonitrile moiety. The molecule is bent at the ether linkage, with a Caryl—O—Caryl bond angle of 116.74 (11)°. In the crystal, molecules are linked by C—H...O hydrogen bonds and other weak interactions forming a supramolecular framework. A Hirshfeld surface analysis was performed to generate two-dimensional fingerprint plots, which reveal the type of interactions occurring in the vicinity of the molecule.

Description: In the title compound, C17H27NO2, the piperidine ring has a chair conformation and is positioned normal to the benzene ring. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming chains propagating along the c-axis direction.

Description: Phenol hemihydrate, C5H5OH·0.5H2O, crystallizes in the space group Pbcn, Z = 8. The previously published crystal structure [CSD refcode PHOLHH; Meuthen & von Stackelberg (1960). Z. Elektrochem. 64, 387–390] is shown to be incorrect. Pairs of phenol molecules, related by an inversion centre, are bridged by one water molecule via O—H...O hydrogen bonds; an extended R 4 4(8) hydrogen-bonded motif links these inversion dimers into chains parallel to the c axis. Packing of the chains is achieved by weaker T-shaped C—H...π interactions between nearest neighbour phenol molecules in the bc plane. Analysis of the thermal expansion and parameterization with a Debye model in terms of the linear elastic moduli shows that the c axis is ∼3 times stiffer than the two orthogonal directions.

Description: The crystal structure of the title sulfonamide, C10H15NO2S, comprises two molecules in the asymmetric unit. The S=O bond lengths of the sulfonamide functional group range from 1.428 (2) to 1.441 (2) Å, with S—C bond lengths of 1.766 (3) Å (for both molecules in the asymmetric unit), and S—N bond lengths of 1.618 (2) and 1.622 (3) Å, respectively. When both molecules are viewed down the N—S bond, the propyl group is gauche to the toluene moiety. In the crystal structure, molecules of the title compound are arranged in an intricate three-dimensional network that is formed via intermolecular C—H...O and N—H...O hydrogen bonds. The crystal structure was refined from a crystal twinned by inversion.

Description: Three new platinum(II) complexes bearing a eugenol and a pyridine derivative, namely (η2-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC 1)chlorido(pyridine-κN)platinum(II), [Pt(C15H19O4)Cl(C5H5N)], (I), (η2-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC 1)chlorido(4-methylpyridine-κN)platinum(II), [Pt(C15H19O4)Cl(C6H7N)], (II), and (η2-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC 1)chlorido(pyridine-4-carboxylic acid-κN)platinum(II), [Pt(C15H19O4)Cl(C6H5NO2)], (III), have been synthesized and further characterized by single-crystal X-ray diffraction. The PtII atoms exhibit the usual distorted square-planar coordination and are surrounded by one Cl atom, one N atom, and a C atom and C=C double bond of the eugenol ligand. The donor N atom of the pyridine ligand occupies a cis position with respect to the double bond. Complexes (I) and (II) crystallize isomorphously in space group Poverline{1} and display a similar crystal packing characterized by C—H...O hydrogen bonding, C—H...π and π–π interactions. However, the presence of the additional methyl group in the 4-methylpyridine ligand in (II) disturbs the π–π interactions. The crystal packing of (III) is characterized by O—H...O hydrogen bonding, resulting in the formation of chains of molecules connected in a head-to-tail fashion and running in the [101] direction. The IC50 values for the HepG2 and KB cell lines are 150.9, 122.3 µM for (I) and 138.9, 93.2 µM for (II), respectively.

Description: In the crystal of the title compound, C7H5FN4S, the molecules are non-planar, with dihedral angle formed by least-squares planes of tetrazole and benzene rings of 59.94 (8) °. The crystal packing is formed by N—H...S hydrogen bonds, which link the molecules into centrosymmetric dimers with an R 2 2(8) ring motif, and by the offset face-to-face π–π stacking interactions between the benzene rings, which join the dimers into layers parallel to (100). The Hirshfeld surface analysis shows that the most important contributions to the surface contacts are from N...H/H...N (21.9%), S...H/H...S (21.1%), H...H (14.6%), F...H/H...F (11.8%) and C...H/H...C (9.5%) interactions.