SHELXT - integrated space-group and crystal-structure determination

Crystal structure of ammonium bis-(pyridine-2,6-di-carboxyl-ato-κ(3) O,N,O')chromate(III) from synchrotron data

The structure of the title compound, (NH4)[Cr(pydc)2] (pydc is pyridine-2,6-di-carboxyl-ate, C7H3NO4), has been determined from synchrotron data. The Cr(III) ion and the N atom of the ammonium cation are located on a crystallographic fourfold rotoinversion axis (-4). The Cr(III) cation is coordinated by four O atoms and the two N atoms of two meridional pydc ligands, displaying a distorted octa-hedral geometry. The Cr-N and Cr-O bond lengths are 1.9727 (15) and 1.9889 (9) Å, respectively. The crystal structure is stabilized by inter-molecular hydrogen bonds involving the N-H groups of the ammonium cation and pyridine C-H groups as donors and the non-coordinating carbonyl O atoms as acceptors.

Crystal structure of bis-[μ-meth-oxy(pyridin-2-yl)methano-lato-κ(3) N,O:O]bis[chlorido-copper(II)]

The racemic title compound, [Cu2(C7H8NO2)2Cl2], is composed of dinuclear mol-ecules in which meth-oxy(pyridin-2-yl)methano-late ligands bridge two symmetry-related Cu(II) ions. Each Cu(II) ion is coordinated in a square-planar geometry by one Cl atom, the N and O atoms of the bidentate ligand and the bridging O atom of the centrosymmetrically related bidentate ligand. The separation between the two Cu(II) atoms is 3.005 (1) Å. In the crystal, non-classical C-H⋯O hydrogen bonds, weak π-π stacking [centroid-centroid distance = 4.073 (1) Å] and weak electrostatic Cu⋯Cl inter-actions [3.023 (1) Å] link the dinuclear mol-ecules into chains running parallel to the b axis. These chains are further connected by weak C-H⋯Cl hydrogen bonds directed approximately along the a axis, forming a three-dimensional supra-molecular network.

Crystal structure of trans-(1,8-dibutyl-1,3,6,8,10,13-hexa-aza-cyclo-tetra-decane-κ(4) N (3),N (6),N (10),N (13))bis-(isonicotinato-κO)copper(II) from synchrotron data

The title compound, [Cu(C6H4NO2)2(C16H38N6)] has been synthesized and characterized by structure analysis based on synchrotron data and by FT-IR spectroscopy. The asymmetric unit consists of half of the Cu(II) complex, the other half being completed by inversion symmetry. The Cu(II) ion has a tetra-gonally distorted octa-hedral coordination sphere with four secondary N atoms of the aza-macrocyclic ligand in the equatorial plane [Cu-Neq = 2.018 (12) Å] and two O atoms of the isonicotinate anions at the axial positions [Cu-Oax = 2.4100 (11) Å]. Intra-molecular N-H⋯O hydrogen bonds between one of the secondary amine N-H groups of the aza-macrocyclic ligand and the non-coordinating O atom of the isonicotinate ions stabilize the mol-ecular structure. Inter-molecular N-H⋯N hydrogen bonds between the other macrocyclic N-H group and the pyridine N atom of an adjacent isonicotinate anion as well as π-π inter-actions [centroid-to-centroid distance 3.711 (2) Å] lead to the formation of rods parallel to [001].

Zn(ii) complex with 2-quinolinecarboxaldehyde selenosemicarbazone: synthesis, structure, interaction studies with DNA/HSA, molecular docking and caspase-8 and -9 independent apoptose induction

A new Zn(ii)-based complex shows a concentration-dependent apoptotic response in highly resistant pancreatic adenocarcinoma cells with extensive activation of caspase-8 and -9.

Addition of phenylacetylene to a magnesium complex of monoiminoacenaphtheneone (dpp-mian)

Reaction of alkoxy-amido magnesium complex 4 with phenylacetylene affords cycloaddition product 6. The protonation of the latter with phenylacetylene results alkoxy-imino derivative 7.

Facile redox state manipulation in Cu(i) frameworks by utilisation of the redox-active tris(4-(pyridin-4-yl)phenyl)amine ligand

Two Cu(i) frameworks were synthesised with the NPy₃ ligand and Cu(ii) salts to yield electroactive Cu(i) frameworks whose spectral properties varied as a function of the redox state.

Synthesis of substituted β-diketiminate gallium hydrides via oxidative addition of H–O bonds

Substituted β-diketiminate gallium hydrides of the general formulaLGa(H)X have been obtained from the oxidative addition reactions of compounds with OH groups intoLGa (L= HC[CMeNAr]₂⁻, Ar = 2,6-iPr₂C₆H₃).

A polymorph of the 6,13-dichloropentacene organic semiconductor: crystal structure, semiconductor measurements and band structure calculations

A new polymorph of the 6,13-dichloropentacene organic semiconductor was discovered, and its properties were compared with those of an earlier reported polymorph.

5-(Fluorodinitromethyl)-2H-tetrazole and its tetrazolates – Preparation and Characterization of New High Energy Compounds

5-(Fluorodinitromethyl)-2H-tetrazole (HFDNTz) has been prepared by the cycloaddition reaction of HN₃ with F(NO₂)₂CCN, which in turn was prepared by aqueous fluorination of sodium dinitrocyanomethanide.

Synthesis and characterization of conjugated/cross-conjugated benzene-bridged boron difluoride formazanate dimers

A study designed to probe the effect of electronic conjugation and cross-conjugation on the optical and electrochemical properties of benzene-bridged boron difluoride formazanate dimers is presented.

Rhodium catalysed conversion of carbenes into ketenes and ketene imines using PNN pincer complexes

PNN pincer-type rhodium complexes catalyze ketene and ketene imine synthesis, using CO or an isocyanide and a carbene precursor.

Preparation and characterization of 3,5-dinitro-1H-1,2,4-triazole

3,5-Dinitro-1H-1,2,4-triazole was isolated as an impact and friction sensitive solid, and fully characterized for the first time. The compound decomposes explosively upon heating to 170 °C. Impurities might lower the decomposition temperature and increase the sensitivity of the material.

Mono- and di-cationic hydrido boron compounds

Stable mono- and di-cationic hydrido boron compounds featuring CH₂BH₂(μ-H)BH₂CH₂ and CH₂BH(μ-H)₂BHCH₂ cores are readily accessible by dehydrogenative hydride abstractions. NBO calculations revealed the occurrence of two B–H–B 3c–2e bonds in the HB(μ-H)₂BH moiety of di-cations (7 and 8), where 43% is located at the H bridges and ∼28% at each boron atom.

Positive and negative allosteric effects of thiacalix[4]arene-based receptors having urea and crown-ether moieties

Allosteric binding behaviors of heteroditopic receptors bearing the 1,3-alternate conformation based thiacalix[4]arene have been evaluated by absorption and ¹H NMR titration experiments.

Cobalt(ii/iii), nickel(ii) and copper(ii) coordination clusters employing a monoanionic Schiff base ligand: synthetic, topological and computational mechanistic aspects

Nine coordination clusters (M = Co^II/III, Ni^II, Cu^II) using a monoanionic Schiff base ligand were synthesized and characterized. A series of transformations occur in the ligand in certain compounds.

Tetraphenolate niobium and tantalum complexes for the ring opening polymerization of ε-caprolactone

Reaction of the pro-ligands α,α,α′,α′-tetra(3,5-di-tert-butyl-2-hydroxyphenyl-p-(or -m-)xylene-para-(or -meta-)tetraphenol with [MCl₅] (M = Nb, Ta) or [Nb(O)Cl₃(NCMe)₂] afforded complexes capable of the ROP of e-caprolactone at high temperature.

Heterometallic complexes with cube-type [MTi3N4] cores containing Group 10 metals in a variety of oxidation states

The metalloligand [{Ti(η⁵-C₅Me₅)(μ-NH)}₃(μ₃-N)] is capable of stabilizing Group 10 metals in the oxidation states 0,iioriv.

Solvent effects in solvo-hydrothermal synthesis of uranyl ion complexes with 1,3-adamantanediacetate

Uranyl ion complexes with 1,3-adamantanediacetate display different topologies arising from variations in coordination mode and the presence of additional ligands.

Homo- and heteroalumoxane silicates

Homo- or hetero alumoxanesilicates or bridged M–OH–M hydroxidesilicates with unusual or unprecedented inorganic cores have been obtained in reactions between 1 and nBuLi, AlMe₃, GaMe₃ or ZnMe₂. The aluminum derivatives serve as models for MAO.

Synthesis and characterization of a novel fluorinated bismaleimide via a nucleophilic addition–elimination reaction and its polymeric networks

A novel fluorinated bismaleimide, OFCP-BMI, was designed and readily synthesized via the nucleophilic addition–elimination reaction of octafluorocyclopentene with maleimide-functionalized phenol.

A new family of high nuclearity CoII/DyIII coordination clusters possessing robust and unseen topologies

Mixing Co(NO₃)₂·6H₂O/Dy(NO₃)₃·6H₂O/(E)-4-(2-hydroxy-3-methoxybenzylideneamino)-2,3-dimethyl-1-phenyl-1,2-dihydropyrazol-5-one (HL)/pivalic acid/Et₃N in various solvents gives products with robust and unseen topologies.

Crystalline adducts of the Lawsone molecule (2-hydroxy-1,4-naphthaquinone): optical properties and computational modelling

Crystal-engineering techniques allow the colour of the molecule in henna dye (Lawsone) to be tuned from yellow to red.

Luminescent pentafluorophenyl-cycloplatinated complexes: synthesis, characterization, photophysics, cytotoxicity and cellular imaging

Pentafluorophenyl cycloplatinated complexes have been synthesized and their photophysical properties studied and investigated by DFT, TD-DFT calculations. The cellular localization and the cytotoxicity of [Pt(C^N)(C₆F₅)(DMSO)] complexes towards two different cell lines has been assessed.