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We present the results of the analysis of 2,2,6,6-tetramethyl-4-oxo-piperidinium nitrate isolated from the stem bark of

In the title compound, C20H19N3O4, the dihedral angles between the central pyrazole ring and the pendant phenyl and substituted benzene rings are 50.95 (8) and 3.25 (12)°, respectively, and an intramolecular C—H...O link generates an S(6) ring. The benzodioxolyl ring adopts a shallow envelope conformation with the methylene C atom as the flap. In the crystal, the molecules are linked by non-classical C—H...O interactions, which generate a three-dimensional network. Solvent-accessible voids run down the c-axis direction and the residual electron density in these voids was modelled during the refinement process using the SQUEEZE algorithm [Spek (2015). Acta Cryst. C71, 9–18] within the structural checking program PLATON.

We present the results of the analysis of 2,2,6,6-tetramethyl-4-oxo-piperidinium nitrate isolated from the stem bark of Vitex doniana, a tree growing in Nigeria. The low-temperature molecular structure comprises one 2,2,6,6-tetramethyl-4-oxopiperidinium cation and one nitrate anion as one molecule in the asymmetric unit. The compound crystallizes in the monoclinic space group P21/n. A portion of the nitrate anion exhibits positional disorder with the main disorder component present 66.253(2) % of the time and the minor disorder component present 33.279(2) % of the time. In comparison with the previously reported room-temperature structure of C9H18N2O4 . The low-temperature structure shows similarity with the piperidinium ring adopting a slightly deformed chair conformation while the nitrate anion is disordered. DFT method was used to complement the experimental study.

Scandenone (warangalone) is a flavonoid found in Erythrina species and other plant genera. It has been connected with physiological processes in insects, human cells and bacteria. In this article, an overview of the biological importance of this compound is provided. A detailed analysis of its crystal structure and antibacterial properties were investigated. The experimental study was supplemented using density functional theory (DFT) and quantitative structure-activity relationship (QSAR) methods. Scandenone proved most potent against Mycobacterium smegmatis (mc2 155) with MIC below 1 μg/mL. In general, it was more potent against Gram-positive bacteria. Scandenone may be a potential tuberculosis medication.

The reaction of 4-amino-1,5-dimethyl-2-phenyl-1,2-di­hydro­pyrazol-3-one with 4-meth­oxy­benzo[1,3]dioxole-5-carbaldehyde resulted in the title compound, which crystallizes in space group C2/c. Two solvent-accessible voids, each of 397 Å3, were found to be evident in the crystal structure., In the title compound, C20H19N3O4, the dihedral angles between the central pyrazole ring and the pendant phenyl and substituted benzene rings are 50.95 (8) and 3.25 (12)°, respectively, and an intra­molecular C—H⋯O link generates an S(6) ring. The benzodioxolyl ring adopts a shallow envelope conformation with the methyl­ene C atom as the flap. In the crystal, the mol­ecules are linked by non-classical C—H⋯O inter­actions, which generate a three-dimensional network. Solvent-accessible voids run down the c-axis direction and the residual electron density in these voids was modelled during the refinement process using the SQUEEZE algorithm [Spek (2015 ▸). Acta Cryst. C71, 9–18] within the structural checking program PLATON.

Dithiocarbamate ligands obtained from primary amines, namely N-phenylaniline, 4-methylaniline and 4-ethylaniline, and represented as L1, L2 and L3 respectively, have been used to prepare some Ni(II), Pd(II) and Pt(II) complexes. The complexes were characterized by NMR, FTIR spectroscopy and elemental analysis. The spectroscopic data showed that the ligands were chelated to the metal ions in a bidentate mode. The complexes [Pt(L1)2], [Pt(L3)2], and [Pd(L1)2] were further characterized by single crystal X-ray analysis and distorted square planar geometries were confirmed in all cases. The magnetic susceptibility measurements of the nickel complexes suggest a square planar geometry for the diamagnetic compounds. Thermal decomposition studies of the complexes gave their respective metal sulfides as residues. Geometry optimization and harmonic frequency calculations of the ligands and the complexes were carried out using density functional theory (DFT). Molecular electrostatic potential energy calculations were used to support the coordination through the dithio-sulfur groups of the three dithiocarbamate ligands. Non-covalent interaction (NCI) theory analysis was used to reveal the different intra and intermolecular interactions in the hydrogen bonded structures of the platinum and palladium complexes. Antimicrobial screening, conducted using selected microbes, showed that the complexes gave moderate to very active antimicrobial activities against Gram negative (Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa), Gram positive (Bacillus cereus and Staphylococcus aureus) and fungi (Candida albicans and Aspergillus flavus) organisms at a concentration of at 50 μg/mL. However, the [Pt(L3)2] complex gave the best antimicrobial properties with an inhibitory zone range of 8–26 mm.

The reactivity of the cobalt(III) complexes dichlorido[tris(2-aminoethyl)amine]cobalt(III) chloride, [CoCl2(tren)]Cl, and dichlorido(triethylenetetramine)cobalt(III) chloride, [CoCl2(trien)]Cl, towards different amino acids (L-proline, L-asparagine, L-histidine and L-aspartic acid) was explored in detail. This study presents the crystal structures of three amino acidate cobalt(III) complexes, namely, (L-prolinato-κ2 N,O)[tris(2-aminoethyl)amine-κ4 N,N′,N′′,N′′′]cobalt(III) diiodide monohydrate, [Co(C5H8NO2)(C6H18N4)]I2·H2O, I, (L-asparaginato-κ2 N,O)[tris(2-aminoethyl)amine-κ4 N,N′,N′′,N′′′]cobalt(III) chloride perchlorate, [Co(C4H7N2O3)(C6H18N4)](Cl)(ClO4), II, and (L-prolinato-κ2 N,O)(triethylenetetramine-κ4 N,N′,N′′,N′′′)cobalt(III) chloride perchlorate, [Co(C4H7N2O3)(C6H18N4)](Cl)(ClO4), V. The syntheses of the complexes were followed by characterization using UV–Vis spectroscopy of the reaction mixtures and the initial rates of reaction were obtained by calculating the slopes of absorbance versus time plots. The initial rates suggest a stronger reactivity and hence greater affinity of the cobalt(III) complexes towards basic amino acids. The biocompatibility of the complexes was also assessed by evaluating the cytotoxicity of the complexes on cultured normal human fibroblast cells (WS1) in vitro. The compounds were found to be nontoxic after 24 h of incubation at concentrations up to 25 mM.

This study was aimed at isolating hypaphorine from Erythrina mildbraedii Harms (Fabaceae) and Erythrina addisioniae Hutch. & Datziel (Fabaceae) in order to determine its structural and antibacterial effects. Density functional theory (DFT) calculations and X-ray crystallographic analysis of the isolated hypaphorine was determined. The antibacterial effects of hypaphorine against a number of Gram positive and Gram negative bacterial strains were investigated. The root mean square deviation between the experimental and calculated bond lengths and bond angles of hypaphorine were found to be 0.046 A and 1.5° respectively. The highest occupied molecular orbital (HOMO) of hypaphorine was delocalised on the indole moiety whereas the lowest occupied molecular orbital (LUMO) was delocalised on the –N(CH3)3 group and the HOMO–LUMO gap of hypaphorine was 4.65 eV. Hypaphorine inhibited the growth of the Gram-positive bacteria tested, namely Bacillus cereus, B. subtilis, Staphylococcus aureus and S. epidermidis. The lowest minimum inhibitory concentration (MIC) value of 2 mg/mL was exhibited against Mycobacterium smegmatis, Staphylococcus aureus and B. subtilis. The theoretical and experimental results from this study showed that hypaphorine is capable of forming quadrupole moments thus explaining its antibacterial effects on Gram positive bacteria.

A complementary application of three analytical techniques, viz. multidimensional nuclear magnetic resonance spectroscopy (NMR), mass spectrometry (MS), and single-crystal X-ray diffractometry was required to identify and refine two natural products isolated from Millettia versicolor and solvent of crystallization. The two compounds, namely 3-(2H-1,3-benzodioxol-5-yl)-6-methoxy-8,8-dimethyl-4H,8H-pyrano[2,3-h]chromen-4-one, or durmillone, (I), and (2E)-1-(4-{[(2E)-3,7-dimethylocta-2,6-dien-1-yl]oxy}-2-hydroxyphenyl)-3-(4-hydroxyphenyl)prop-2-en-1-one, (II), could not be separated by routine column chromatography and cocrystallized in a 2:1 ratio with 0.13 molecules of ethanol solvent. Compound (II) and ethanol could not be initially identified by single-crystal X-ray analysis due to complex disorder in the aliphatic chain region of (II). Mass spectrometry ensured that (II) represented only one species disordered over several positions in the solid state, rather than several species cohabitating on the same crystallographic site. The atomic identification and connectivity in (II) were established by several 2D (two-dimensional) NMR techniques, which in turn relied on a knowledge of its exact mass. The derived connectivity was then used in the single-crystal analysis to model the disorder of the aliphatic chain in (II) over three positions and allowed identification of a partially occupied ethanol solvent molecule that was disordered over an inversion center. The disordered moieties were refined with restraints and constraints.

The title compound, [Cd2(C7H10NS2)4], is a neutral dinuclear cadmium(II) complex bearing four bisN,N-diallyldithiocarbamate ligands coordinating to two CdIIcations. In each of the monomeric subunits, there are four S atoms of two dithiocarbamate ligands [Cd—S = 2.5558 (3), 2.8016 (3), 2.6050 (3) and 2.5709 (3) Å] that coordinate to one CdIIatom in a bidentate mode. The dimers are located over an inversion centre bridged by two additional bridging Cd—S bonds [2.6021 (3) Å], leading to a substantial distortion of the geometry of the monomeric subunit from the expected square-planar geometry. The five-coordinate environment around each of the CdIIions in the dimer is best described as substantially tetragonally distorted square pyramidal. The dithiocarbamate groups are themselves planar and are also coplanar with the CdIIions. The negative charge on these groups is delocalized by resonance across the S atoms bound to the CdIIcation. This delocalization of the π electrons in the dithiocarbamate groups also extends to the C—N bonds as they reveal significant double bond character [C—N = 1.3213 (16) and 1.3333 (15) Å].

The acidity of the amine H atoms and the consequent salt formation ability of ethylenedinitramine (EDNA) were analyzed in an attempt to improve the thermal stability of EDNA. Two short-chain alkanediamine bases, namely propane-1,3-diamine and butane-1,4-diamine, were chosen for this purpose. The resulting salts, namely propane-1,3-diaminium N,N′-dinitroethylenediazanide, C3H12N2 2+·C2H4N4O4 2−, and butane-1,4-diaminium N,N′-dinitroethylenediazanide, C4H14N2 2+·C2H4N4O4 2−, crystallize in the orthorhombic space group Pbca and the monoclinic space group P21/n, respectively. The resulting salts display extensive hydrogen-bonding networks because of the presence of ammonium and diazenide ions in the crystal lattice. This results in an enhanced thermal stability and raises the thermal decomposition temperatures to 202 and 221 °C compared to 180 °C for EDNA. The extensive hydrogen bonding present also plays a crucial role in lowering the sensitivity to impact of these energetic salts.

The 100 K structures of two salts, namely 2-amino-1H-benzimidazolium 3-phenylpropynoate, C7H8N3+·C9H5O2−, (I), and 2-amino-1H-benzimidazolium oct-2-ynoate, C7H8N3+·C8H11O2−, (II), both have monoclinic symmetry (space groupP21/c) and display N—H...O hydrogen bonding. Both structures show packing with corrugated sheets of hydrogen-bonded molecules lying parallel to the [001] direction. Two hydrogen-bonded ring motifs can be identified and described with graph setsR22(8) andR44(16), respectively, in both (I) and (II). Computational chemistry calculations performed on both compounds show that the hydrogen-bonded ion pairs are more energetically favourable in the crystal structure than their hydrogen–bonded neutral molecule counterparts.

The characteristic feature of this cadmium(II) complex is the formation of a dimeric bridged structure where the two CdII cations are bridged by S atoms from the N,N-di­allyl­ldi­thio­carbamate ligands., The title compound, [Cd2(C7H10NS2)4], is a neutral dinuclear cadmium(II) complex bearing four bis N,N-di­allyl­di­thio­carbamate ligands coordinating to two CdII cations. In each of the monomeric subunits, there are four S atoms of two di­thio­carbamate ligands [Cd—S = 2.5558 (3), 2.8016 (3), 2.6050 (3) and 2.5709 (3) Å] that coordinate to one CdII atom in a bidentate mode. The dimers are located over an inversion centre bridged by two additional bridging Cd—S bonds [2.6021 (3) Å], leading to a substantial distortion of the geometry of the monomeric subunit from the expected square-planar geometry. The five-coordinate environment around each of the CdII ions in the dimer is best described as substanti­ally tetra­gonally distorted square pyramidal. The di­thio­carbamate groups are themselves planar and are also coplanar with the CdII ions. The negative charge on these groups is delocalized by resonance across the S atoms bound to the CdII cation. This delocalization of the π electrons in the di­thio­carbamate groups also extends to the C—N bonds as they reveal significant double bond character [C—N = 1.3213 (16) and 1.3333 (15) Å].

C3H11N2I, monoclinic, P21/n (no. 14), a = 5.0152(2) Å, b = 10.1470(4) Å, c = 14.1852(5) Å, β = 96.501(2)°, V = 717.23(5) Å3, Z = 4, R gt(F) = 0.0174, wR ref(F 2) = 0.0411, T = 100 K.

The crystal structure of the title salt, C5H16N22+·2Br−, withZ= 12 and more unusuallyZ′ = 3, forms part of a small group of crystal structures in the Cambridge Structural Database that are ammonium bromide salts. One of the diaminium cation chains in the asymmetric unit exhibits positional disorder, which was modelled using a suitable disorder model. This compound also exhibits organic–inorganic layering in its packing arrangement that is typical of this class of compound. An extensive complex three-dimensional hydrogen-bonding network is also identified. The hydrogen bonds evident in this crystal structure were identified as being most likely strong charge-assisted hydrogen bonds.

In the title compound, (C(20)H(26)P)(2)[Pd(2)Cl(6)], the Pd(II) atom within the hexachloridodipalladate(II) dianion has a square-planar geometry. It resides on a centre of inversion with the asymmetric unit containing half of the dianion and one phospho-nium cation. Only weak C-H⋯π inter-actions are present in the crystal structure.

The structure of the title compound, [Pd(C(2)H(3)O(2))(C(20)H(26)P)], shows a distorted square-planar geometry for the Pd(II) atom, with significant deviations being evident owing to the asymmetric coordination mode of the acetate ligand. A weak intra-molecular C-H⋯O inter-action is noted. The crystal studied was a racemic twin.

C664 molecule of water. These cations adopt a typical chair conformation and are alternate with hexachloridoindiumate complex forming layers parallel to the (10-1) plane (Fig.1). In the crystal, the components of the structure are linked via intra and intermolecular N---H...O, O-H... Cl, C-H...O and N-H...Cl hydrogen bonds to form a complex threedimensional network. Additional stabilization within these layers is provided by weak intermolecular C-H...Cl interactions.

In the title Ru(II) complex, [RuCl(2)(C(8)H(12))(C(2)H(3)N)(2)]·CH(3)CN, the metal ion is coordinated to the centers of each of the double bonds of the cyclo-octa-diene ligand, to two chloride ions (in cis positions) and to two N-atom donors (from MeCN mol-ecules) that complete the coordination sphere for the neutral complex. The coordination about the Ru(II) atom can thus be considered to be octa-hedral with a slightly trigonal distortion. There is also one acetonitrile solvent mol-ecule per mol-ecule which is outside the coordination sphere of the ruthenium atom.