Copper(II) coordination polymers have attracted considerable interest due to their catalytic, adsorption, luminescence and magnetic properties. The reactions of copper(II) with 2-amino-4-sulfobenzoic acid (H(2)asba) in the presence/absence of the auxiliary chelating ligand 1,10-phenanthroline (phen) under ambient conditions yielded two supramolecular coordination polymers, namely (3-amino-4-carboxybenzene-1-sulfonato-κO(1))bis(1,10-phenanthroline-κ(2)N,N')copper(II) 3-amino-4-carboxybenzene-1-sulfonate monohydrate, [Cu(C7H6N2O5S)(C12H8N2)2](C7H6N2O5S)·H2O, (1), and catena-poly[[diaquacopper(II)]-μ-3-amino-4-carboxylatobenzene-1-sulfonato-κ(2)O(4):O(4')], [Cu(C7H6N2O5S)(H2O)2]n, (2). The products were characterized by FT-IR spectroscopy, thermogravimetric analysis (TGA), solid-state UV-Vis spectroscopy and single-crystal X-ray diffraction analysis, as well as by variable-temperature powder X-ray diffraction analysis (VT-PXRD). Intermolecular π-π stacking interactions in (1) link the mononuclear copper(II) cation units into a supramolecular polymeric chain, which is further extended into a supramolecular double chain through interchain hydrogen bonds. Supramolecular double chains are then extended into a two-dimensional supramolecular double layer through hydrogen bonds between the lattice Hasba(-) anions, H2O molecules and double chains. Left- and right-handed 21 helices formed by the Hasba(-) anions are arranged alternately within the two-dimensional supramolecular double layers. Complex (2) exhibits a polymeric chain which is further extended into a three-dimensional supramolecular network through interchain hydrogen bonds. Complex (1) shows a reversible dehydration-rehydration behaviour, while complex (2) shows an irreversible dehydration-rehydration behaviour.
A new cadmium-thiocyanate complex, namely catena-poly[1-carboxymethyl-4-(dimethylamino)pyridinium [cadmium(II)-tri-μ-thiocyanato-κ(4)N:S;κ(2)S:N] [[[4-(dimethylamino)pyridinium-1-acetate-κ(2)O,O']cadmium(II)]-di-μ-thiocyanato-κ(2)N:S;κ(2)S:N]], {(C9H13N2O2)[Cd(NCS)3][Cd(NCS)2(C9H12N2O2)]}n, was synthesized by the reaction of 4-(dimethylamino)pyridinium-1-acetate, cadmium nitrate tetrahydrate and potassium thiocyanide in aqueous solution. In the crystal structure, two types of Cd(II) atoms are observed in distorted octahedral coordination environments. One type of Cd(II) atom is coordinated by two O atoms from the carboxylate group of the 4-(dimethylamino)pyridinium-1-acetate ligand and by two N atoms and two S atoms from four different thiocyanate ligands, while the second type of Cd(II) atom is coordinated by three N atoms and three S atoms from six different thiocyanate ligands. Neighbouring Cd(II) atoms are linked by thiocyanate bridges to form a one-dimensional zigzag chain and a one-dimensional coordination polymer. Hydrogen-bond interactions are involved in the formation of the supramolecular network.
The title compound, C12H13NO4, is one of the few examples that exhibits a syn conformation between the amide and ester carbonyl groups of the oxalyl group. This conformation allows the engagement of the amide H atom in an intramolecular three-centred hydrogen-bonding S(6)S(5) motif. The compound is self-assembled by C=O...C=O and amide-π interactions into stacked columns along the b-axis direction. The concurrence of both interactions seems to be responsible for stabilizing the observed syn conformation between the carbonyl groups. The second dimension, along the a-axis direction, is developed by soft C-H...O hydrogen bonding. Density functional theory (DFT) calculations at the B3LYP/6-31G(d,p) level of theory were performed to support the experimental findings.
Trioctylphosphine oxide (TOPO), C(24)H(51)OP, was recrystallized from ambient evaporation in acetone. TOPO single crystals form with a monoclinic P2(1)/c structure. Fourier transform IR (FT-IR) spectroscopy captures the characteristic stretching modes from the seven methylene groups, the phosphoryl P=O bond, and the phosphoryl-carbon bond.
The peptide N-benzyloxycarbonyl-L-valyl-L-tyrosine methyl ester or NCbz-Val-Tyr-OMe (where NCbz is N-benzyloxycarbonyl and OMe indicates the methyl ester), C(23)H(28)N(2)O(6), has an extended backbone conformation. The aromatic rings of the Tyr residue and the NCbz group are involved in various attractive intra- and intermolecular aromatic π-π interactions which stabilize the conformation and packing in the crystal structure, in addition to N-H...O and O-H...O hydrogen bonds. The aromatic π-π interactions include parallel-displaced, perpendicular T-shaped, perpendicular L-shaped and inclined orientations.
A potentially pentadentate hydrazone ligand,N′-[1-(pyrazin-2-yl)ethylidene]nicotinohydrazide (HL), was prepared from the condensation reaction of nicotinohydrazide and acetylpyrazine. Reactions of HLwith MnCl2, Mn(CH3COO)2and Cd(CH3COO)2afforded three metal complexes, namely dichlorido{N′-[1-(pyrazin-2-yl-κN1)ethylidene]nicotinohydrazide-κ2N′,O}manganese(II), [MnCl2(C12H11N5O)], (I), bis{N′-[1-(pyrazin-2-yl-κN1)ethylidene]nicotinohydrazidato-κ2N′,O]manganese(II), [Mn(C12H10N5O)2], (II), and poly[[(acetato-κ2O,O′){μ3-N′-[1-(pyrazin-2-yl-κ2N1:N4)ethylidene]nicotinohydrazidato-κ3N′,O:N1}cadmium(II)] chloroform disolvate], {[Cd(C12H10N5O)(CH3COO)]·2CHCl3}n, (III), respectively. Complex (I) has a mononuclear structure, the MnIIcentre adopting a distorted square-pyramidal coordination. Complex (II) also has a mononuclear structure, with the MnIIcentre occupying a special position (C2symmetry) and adopting a distorted octahedral coordination environment, which is defined by two O atoms and four N atoms from twoN′-[1-(pyrazin-2-yl)ethylidene]nicotinohydrazidate (L−) ligands relatedviaa crystallographic twofold axis. Complex (III) features a unique three-dimensional network with rectangular channels, and theL−ligand also serves as a counter-anion. The coordination geometry of the CdIIcentre is pentagonal bipyramidal. This study demonstrates that HL, which can act as either a neutral or a mono-anionic ligand, is useful in the construction of interesting metal–organic compounds.
The preparation and X-ray and spectroscopic studies of the title copper(II) complex, [Cu(C12H8N3O2)(CN)(H2O)], are reported. The Cu(II) cation is five-coordinated, forming a distorted square-planar pyramid with an Addison τ parameter of 0.14. The UV-vis spectrum shows a d-d transition of the Cu(II) centre at 638 nm, and the electron paramagnetic resonance (EPR) spectrum confirms that the Cu(II) cation has an axial symmetry coordination and that the unpaired electrons occupy the d(x(2)-y(2)) orbital. Cyclic voltammetric studies show two irreversible oxidation and reduction peaks.
Four crystal structures of 3-cyano-6-hydroxy-4-methyl-2-pyridone (CMP),viz.the dimethyl sulfoxide monosolvate, C7H6N2O2·C2H6OS, (1), theN,N-dimethylacetamide monosolvate, C7H6N2O2·C4H9NO, (2), a cocrystal with 2-amino-4-dimethylamino-6-methylpyrimidine (as the salt 2-amino-4-dimethylamino-6-methylpyrimidin-1-ium 5-cyano-4-methyl-6-oxo-1,6-dihydropyridin-2-olate), C7H13N4+·C7H5N2O2−, (3), and a cocrystal withN,N-dimethylacetamide and 4,6-diamino-2-dimethylamino-1,3,5-triazine [as the solvated salt 2,6-diamino-4-dimethylamino-1,3,5-triazin-1-ium 5-cyano-4-methyl-6-oxo-1,6-dihydropyridin-2-olate–N,N-dimethylacetamide (1/1)], C5H11N6+·C7H5N2O2−·C4H9NO, (4), are reported. Solvates (1) and (2) both contain the hydroxy group in aparaposition with respect to the cyano group of CMP, acting as a hydrogen-bond donor and leading to rather similar packing motifs. In cocrystals (3) and (4), hydrolysis of the solvent molecules occurs and anin situnucleophilic aromatic substitution of a Cl atom with a dimethylamino group has taken place. Within all four structures, anR22(8) N—H...O hydrogen-bonding pattern is observed, connecting the CMP molecules, but the pattern differs depending on which O atom participates in the motif, either theorthoorparaO atom with respect to the cyano group. Solvents and coformers are attached to these arrangementsviasingle-point O—H...O interactions in (1) and (2) or by additionalR44(16) hydrogen-bonding patterns in (3) and (4). Since thein situnucleophilic aromatic substitution of the coformers occurs, the possible Watson–Crick C–G base-pair-like arrangement is inhibited, yet the cyano group of the CMP molecules participates in hydrogen bonds with their coformers, influencing the crystal packing to form chains.
Three 1-phenylindolin-2-one derivatives, namely 1-phenylindolin-2-one, C14H11NO, (I), 5-bromo-1-phenylindolin-2-one, C14H10BrNO, (II), and 5-iodo-1-phenylindolin-2-one, C14H10INO, (III), have been synthesized and their structures determined. Compounds (I) and (II) crystallized in the centrosymmetric space groups Pbca and P21/c, respectively, while compound (III) crystallized in the polar space group Aea2. Density functional theory (DFT) calculations show that the molecular dipole moment gradually decreases in the order (I) > (II) > (III). The relatively smaller dipole moment of (III) and the larger non-electrostatic intermolecular interactions may be the main reasons for the noncentrosymmetric and polar structure of (III).
Section C is continuing its transition to a journal that publishes exciting science with structural content, in particular important results relating to the chemical sciences.Section C is the journal of choice for the rapid publication of articles that highlight interesting research facilitated by the determination, calculation or analysis of structures of any type, other than macromolecular structures.Articles that emphasize the science and the outcomes that were enabled by the study are particularly welcomed.Authors are encouraged to include mainstream science in their papers, thereby producing manuscripts that are substantial scientific well-rounded contributions that appeal to a broad community of readers and increase the profile of the authors.One change that readers of the journal will notice in the near future is that the journal's website (journals.iucr.org/c)will be redesigned completely.This will enable highlighting of the most recent significant articles on the homepage and easy navigation to articles for readers, while making all necessary information for prospective authors readily accessible.As part of the transition, the journal aims to publish special issues on a regular basis.In February 2014, a special issue on Computational Materials Discovery was published and attracted considerable attention and downloads.A virtual issue on Coordination Polymers was also published in July 2014.Two more special issues are in the pipeline: one on The Structural Chemistry of Homogeneous and Heterogeneous Catalysts and one on NMR Crystallography.The latter is a rapidly emerging field and its importance to structural scientists was recently recognized by the establishment of the IUCr Commission on NMR Crystallography and Related Methods during the 2014 IUCr Congress in Montreal.It is hoped that Section C can become a leading journal for the publication of results relating to this field.In conjunction with the new outlook of the journal, it was decided to add a second Main Editor to the editorial board.I am delighted to welcome Paul Raithby from the University of Bath, UK, as a Main Editor.Paul's reputation and network in the chemistry and crystallography communities make him an invaluable addition to the team and will bolster the journal's interface with the chemistry community.To further promote awareness of the expansion of the scope of Section C to cover all areas of Structural Chemistry, in August 2014 representatives of the journal were present at the ACS Fall Meeting in San Francisco to promote this fact.It is anticipated that Section C will have a presence in 2015 at further Chemistry-focused meetings, such as the
Two organic-inorganic hybrid compounds have been prepared by the combination of the 4-[(E)-2-(pyridin-1-ium-2-yl)ethenyl]pyridinium cation with perhalometallate anions to give 4-[(E)-2-(pyridin-1-ium-2-yl)ethenyl]pyridinium tetrachloridocobaltate(II), (C12H12N2)[CoCl4], (I), and 4-[(E)-2-(pyridin-1-ium-2-yl)ethenyl]pyridinium tetrachloridozincate(II), (C12H12N2)[ZnCl4], (II). The compounds have been structurally characterized by single-crystal X-ray diffraction analysis, showing the formation of a three-dimensional network through X-H...ClnM(-) (X = C, N(+); n = 1, 2; M = Co(II), Zn(II)) hydrogen-bonding interactions and π-π stacking interactions. The title compounds were also characterized by FT-IR spectroscopy and thermogravimetric analysis (TGA).
The title compound, [Pb(C4H3N2S)2]n, was prepared by the reaction of [Pb(OAc)2]·3H2O (OAc is acetate) with pyrimidine-2-thione in the presence of triethylamine in methanol. In the crystal structure, the Pb(II) atom has an N4S4 coordination environment with four ligands coordinated by N- and S-donor atoms. This compound shows that the pyrimidine-2-thiolate anion can lead to a three-dimensional network when the coordination number of the metal ion can be higher than 6, as is the case with the Pb(II) ion. This compound presents only covalent bonds, showing that despite the possibility of the hemidirected geometries of Pb(II), the eight-coordinated ion does not allow the formation of an isolated molecular structure with pyrimidine-2-thiolate as the ligand.
Two new acylamide metal–organic frameworks (MOFs), based on mixedN- andO-donor ligands, with 4-connected topologies have been obtained, namely poly[[μ2-N1,N4-bis(pyridin-3-yl)terephthalamide]bis(μ3-4,4′-oxydibenzoato)dizinc(II)], [Zn2(C14H8O5)2(C18H14N4O2)]n, (1), and poly[[(μ2-benzene-1,4-dicarboxylato)[μ2-N4,N4′-bis(pyridin-3-yl)-[1,1′-biphenyl]-4,4′-dicarboxamide]dicadmium(II)] dihydrate], {[Cd(C8H4O4)(C24H18N4O2)]·2H2O}n, (2). Complex (1) is a 4-connected CdSO4net with no interpenetration, where the ZnIIcation is regarded as a 4-connecting node with square geometry. Complex (2) is a 4-connecteddianet with threefold interpenetration, where the CdIIcation acts as a 4-connecting node with tetrahedral geometry. The results of thermogravimetric and luminescence analyses are described in detail.
Metal–organic frameworks (MOFs) have potentially useful applications and an intriguing variety of architectures and topologies. Two homochiral coordination polymers have been synthesized by the hydrothermal method, namely poly[(μ- N -benzyl-L-phenylalaninato-κ 4 O , O ′: O , N )(μ-formato-κ 2 O : O ′)zinc(II)], [Zn(C 16 H 16 NO 2 )(HCOO)] n , (1), and poly[(μ- N -benzyl-L-leucinato-κ 4 O , O ′: O , N )(μ-formato-κ 2 O : O ′)zinc(II)], [Zn(C 13 H 18 NO 2 )(HCOO)] n , (2), and studied by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy and fluorescence spectroscopy. Compounds (1) and (2) each have a two-dimensional layer structure, with the benzyl or isobutyl groups of the ligands directed towards the interlayer interface. Photoluminescence investigations show that both (1) and (2) display a strong emission in the blue region.
In the title compound, [Cu(C7H3N2O4)(C4H5N2)(H2O)], (I), pyridine-2,6-dicarboxylate (pydc(2-)), 2-aminopyrimidine and aqua ligands coordinate the Cu(II) centre through two N atoms, two carboxylate O atoms and one water O atom, respectively, to give a nominally distorted square-pyramidal coordination geometry, a common arrangement for copper complexes containing the pydc(2-) ligand. Because of the presence of Cu...Xbridged contacts (X = N or O) between adjacent molecules in the crystal structures of (I) and three analogous previously reported compounds, and the corresponding uncertainty about the effective coordination number of the Cu(II) centre, density functional theory (DFT) calculations were used to elucidate the degree of covalency in these contacts. The calculated Wiberg and Mayer bond-order indices reveal that the Cu...O contact can be considered as a coordination bond, whereas the amine group forming a Cu...N contact is not an effective participant in the coordination environment.
The name `bath salts', for an emerging class of synthetic cathinones, is derived from an attempt to evade prosecution and law enforcement. These are truly illicit drugs that have psychoactive CNS (central nervous system) stimulant effects and they have seen a rise in abuse as recreational drugs in the last few years since first having been seen in Japan in 2006. The ease of synthesis and modification of specific functional groups of the parent cathinone make these drugs particularly difficult to regulate. MDPV (3,4-methylenedioxypyrovalerone) is commonly encountered as its hydrochloride salt (C16H21NO3·HCl), in either the hydrated or the anhydrous forms. This `bath salt' has various names in the US, e.g. `Super Coke', `Cloud Nine', and `Ivory Wave', to name just a few. We report here the structures of two forms of the HCl salt, one as a mixed bromide/chloride salt, C16H22NO3(+)·0.343Br(-)·0.657Cl(-) [systematic name: 1-(benzo[d][1,3]dioxol-5-yl)-2-(pyrrolidin-1-ium-1-yl)pentan-1-one bromide/chloride (0.343/0.657)], and the other with the H7O3(+) cation, as well as the HCl counter-ion [systematic name: hydroxonium 1-(benzo[d][1,3]dioxol-5-yl)-2-(pyrrolidin-1-ium-1-yl)pentan-1-one dichloride, H7O3(+)·C16H22NO3(+)·2Cl(-)]. This is one of a very few structures (11 to be exact) in which we have a new example of a precisely determined hydroxonium cation. During the course of researching the clandestine manufacture of MDPV, we were surprised by the fact that a common precursor of this illicit stimulant is known to be the fragrant species piperonal, which is present in the fragrances of orchids, most particularly in the case of the vanilla orchid. We found that MDPV can be made by a Grignard reaction of this heliotropin. This may also explain the unexpected appearance of the bromide counter-ion in some of the salts we encountered (C16H21NO3·HBr), one of which is presented here [systematic name: 1-(benzo[d][1,3]dioxol-5-yl)-2-(pyrrolidin-1-ium-1-yl)pentan-1-one bromide, C16H22NO3(+)·Br(-)]. Complexation of MDPV with a forensic crystallizing reagent, HAuCl4, yields the tetrachloridoaurate salt of this drug, (C16H22NO3)[AuCl4]. The heavy-metal complexing agent HAuCl4 has been used for over a century to identify common quarternary nitrogen-containing drugs via microscopic identification. Another street drug, called ethylone (3,4-methylenedioxyethylcathinone), is regularly sold and abused as its hydrochloride salt (C12H15NO3·HCl), and its structure is herein described (systematic name: N-{1-[(benzo[d][1,3]dioxol-5-yl)carbonyl]ethyl}ethanaminium chloride, C12H16NO3(+)·Cl(-)). Marketed and sold as a `bath salt', `plant feeder', or `cleaning product', this drug is nothing more than a slight chemical modification of the banned drug methylone (3,4-methylenedioxymethcathinone). As with previously popular synthetic cathinones, the abuse of ethylone has seen a recent increase due to regulatory efforts on previous generations of cathinones that are now banned.
A new cadmium dicyanamide complex, poly[tetramethylphosphonium [μ-chlorido-di-μ-dicyanamido-κ(4)N(1):N(5)-cadmium(II)]], [(CH3)4P][Cd(NCNCN)2Cl], was synthesized by the reaction of tetramethylphosphonium chloride, cadmium nitrate tetrahydrate and sodium dicyanamide in aqueous solution. In the crystal structure, each Cd(II) atom is octahedrally coordinated by four terminal N atoms from four anionic dicyanamide (dca) ligands and by two chloride ligands. The dicyanamide ligands play two different roles in the building up of the structure; one role results in the formation of [Cd(dca)Cl]2 building blocks, while the other links the building blocks into a three-dimensional structure. The anionic framework exhibits a solvent-accessible void of 673.8 Å(3), amounting to 47.44% of the total unit-cell volume. The cavities in the network are occupied by pairs of tetramethylphosphonium cations.
