The Catalytic Activity of Polyaniline in Hydrogenation Reactions with Molecular Hydrogen.

This study unveils a novel property of polyaniline by establishing its catalytic activity in heterogeneous hydrogenation with molecular hydrogen. Polyaniline was activated by heat-treating at different temperatures in a hydrogen atmosphere. The sample treated at 300 °C exhibited the highest catalytic activity for ethylene hydrogenation in the gas phase at atmospheric pressure and for p-nitrotoluene or α-methylstyrene hydrogenation in the liquid phase.

Magnetocaloric effect in 1D-polymers bearing 15-metallacrown-5 {GdCu} units and anionic oxalate complexes.

Two complexes {[GdCu(GlyHA)(HO)Cr(CO)]·11.02HO} (1) and {{[GdCu(GlyHA)(HO)]μ-[Cu(CO)(HO)]}μ-[Cu(CO)]·15.8HO} (2), were obtained as outcomes of the reactions between the cationic hexanuclear {GdCu(GlyHA)} 15-metallacrown-5 complex (where GlyHA = glycinehydroxamate) and the anionic oxalate complexes K[Cr(CO)] or K[Cu(CO)].

Parallel Minisci Reaction of -Difluorocycloalkyl Building Blocks.

Parallel Minisci reactions of nonfluorinated and -difluorinated C-C cycloalkyl building blocks (trifluoroborates and carboxylic acids) with a series of electron-deficient heterocycles were studied. A comparison of the reaction's outcome revealed better product yields in the case of carboxylic acids as the radical precursors in most cases, albeit these reagents were used with three-fold excess under optimized conditions. The nature of the heterocyclic core was found to be important for successful incorporation of the cycloalkyl fragment.

Synthesis and crystal structure of a cadmium(II) coordination polymer based on 4,4'-(1-1,2,4-triazole-3,5-di-yl)dibenzoate.

The asymmetric unit of the title compound, -poly[[[aqua-bis-(pyridine-κ)cadmium(II)]-μ-4,4'-(1-1,2,4-triazole-3,5-di-yl)dibenzoato-κ ,':'','''] 4.5-hydrate], {[Cd(CHNO)(CHN)(HO)]·4.5HO} or {[Cd(bct)(py)(HO)]·4.

Advances and Challenges in Development of Transition Metal Catalysts for Heterogeneous Hydrogenation of Organic Compounds.

Actual problems of development of catalysts for hydrogenation of heterocyclic compounds by hydrogen are summarized and discussed. The scope of review covers composites of nanoparticles of platinum group metals and 3d metals for heterogeneous catalytic processes. Such problems include increase of catalyst activity, which is important for reduction of precious metals content; development of new catalytic systems which do not contain metals of platinum group or contain cheaper analogues of Pd; control of factors which make influence on the selectivity of the catalysts; achievement of high reproducibility of the catalyst's performance and quality control of the catalysts.

Crystal structures of the complexes containing macrocyclic cations [(cyclam)] ( = Ni, Zn) and tetra-iodido-cadmate(2-) anion.

The asymmetric units of the isostructural compounds (1,4,8,11-tetra-aza-cyclo-tetra-decane-κ )nickel(II) tetra-iodido-cadmate(II), [Ni(CHN)][CdI] (), and tri-iodido-1κ -μ-iodido-(1,4,8,11-tetra-aza-cyclo-tetra-decane-2κ )cad-mium(II)zinc(II), [CdZnI(CHN)] () (CHN = 1,4,8,11-tetra-aza-cyclo-tetra-decane, cyclam, ), consist of the centrosymmetric macrocyclic cation [()] [ = Ni or Zn] with the metal ion lying on a twofold screw axis, and the tetra-iodo-cadmate anion [CdI] located on the mirror plane. In , the anion acts as an uncoordinated counter-ion while in it is bound to the Zn atom one of the iodide atoms, thus forming an electroneutral heterobimetallic complex [Zn()(CdI)]. The Ni and Zn ions are coordinated in a square-planar manner by the four secondary N atoms of the macrocyclic ligand , which adopts the most energetically stable -III conformation.

Redox Behavior of Cobalt-Phosphine Complexes vs Their Catalytic Activity in Organozinc Compound Formation: Background for Mechanistic Investigations.

Catalytic activity in arylzinc compound formation was studied for eight Co complexes with phosphines along with their redox properties for implementing the idea of rational design. It was found that Co(XantPhos)Cl and Co(-XantPhos)Cl demonstrated distinct reversible Co/Co redox processes and acted as efficient catalysts of arylzinc compound formation. Meanwhile, for Co(DPEphos)Cl, Co(dppf)Cl, Co(dppb)Cl, Co(PPh)Cl, and Co(XantPhos)(Piv) (the latter one without the addition of LiCl), reversible redox processes were not observed.

Screening of Palladium/Charcoal Catalysts for Hydrogenation of Diene Carboxylates with Isolated-Rings (Hetero)aliphatic Scaffold.

A series of seven palladium-containing composites, i.e., four Pd/C and three Pd(OH)/C (Pearlman's catalysts), was prepared using modified common approaches to deposition of Pd or hydrated PdO on charcoal.

Catalytic Oxidation of Benzoins by Hydrogen Peroxide on Nanosized HKUST-1: Influence of Substituents on the Reaction Rates and DFT Modeling of the Reaction Path.

In this research, the oxidation of a series of benzoins, R-C(=O)-CH(OH)-R, where R = phenyl, 4-methoxyphenyl, 4-bromophenyl, and 2-naphthyl, by hydrogen peroxide in the presence of nanostructured HKUST-1 (suspension in acetonitrile/water mixture) was studied. The respective benzoic acids were the only products of the reactions. The initial average reaction rates were experimentally determined at different concentrations of benzoin, HO and an effective concentration of HKUST-1.

Syntheses and structural characterizations of the first coordination polymers assembled from the Ni(cyclam) cation and the benzene-1,3,5-tri-carboxyl-ate linker.

The asymmetric unit of -poly[[[(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ , , , )nickel(II)]-μ-5-carb-oxy-benzene-1,3-di-carboxyl-ato-κ : ] octa-hydrate], {[Ni(CHO)(CHN)]·8HO} (), consists of a macrocyclic Ni cation, a carboxyl-ate dianion and eight highly disordered water mol-ecules of crystallization. The components of the compound -poly[[[(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ , , , )nickel(II)]-μ-5-carb-oxy-benzene-1,3-di-carboxyl-ato-κ : ] monohydrate], {[Ni(CHO)(CHN)]·HO} (), are two crystallographically unique centrosymmetric macrocyclic dications, a carboxyl-ate dianion and one water mol-ecule of crystallization. In each compound, the metal ion is coordinated in the equatorial plane by the four secondary N atoms of the macrocyclic ligand, which adopts the most energetically stable -III conformation, and two mutually O atoms of the carboxyl-ate anions in a slightly tetra-gonally distorted -NiNO octa-hedral geometry.

Synthesis and crystal structure of di-aqua-(1,4,8,11-tetra-aza-cyclo-tetra-deca-ne)zinc(II) bis-(hydrogen 4-phospho-natobiphenyl-4'-carboxyl-ato)(1,4,8,11-tetra-aza-cyclo-tetra-deca-ne)zinc(II).

In the asymmetric unit of the title compound, -di-aqua-(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ , , , )zinc(II) -bis-(hydrogen 4-phospho-natobiphenyl-4'-carboxyl-ato-κ)(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ , , , )zinc(II), [Zn(CHN)(HO)][Zn(CHOP)(CHN)], both Zn atoms lie on crystallographic inversion centres and the atoms of the macrocycle in the cation are disordered over two sets of sites. In both macrocyclic units, the metal ions possess a tetra-gonally elongated ZnNO octa-hedral environment formed by the four secondary N atoms of the macrocyclic ligand in the equatorial plane and the two O atoms of the water mol-ecules or anions in the axial positions, with the macrocyclic ligands adopting the most energetically favourable -III conformation. The average Zn-N bond lengths in both macrocyclic units do not differ significantly [2.

Synthesis and crystal structure of -di-aqua(1,4,8,11-tetra-aza-undeca-ne)copper(II) isophthalate monohydrate.

In the title hydrated mol-ecular salt, [Cu(CHN)(HO)](CHO)·HO, the metal ion is coordinated by the two primary and two secondary N atoms of the amine ligand and the mutually O atoms of the water mol-ecules in a tetra-gonally distorted octa-hedral geometry. The average equatorial Cu-N bond lengths (2.013 and 2.

Improvement of laccase biosensor characteristics using sulfur-doped TiO nanoparticles.

The search for new nanoscale materials with predictable properties to target the timely and fast detection of toxic components in wastewater is one of the most promising directions of modern biosensorics. We have shown that TiO nanoparticles modified with sulfur significantly improve the main operational parameters of laccase-based electrodes when compared with controls. The nanoparticle samples were labeled as TiOS(0.

Synthesis and crystal structure of bis-[-di-aqua-(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ , , , )nickel(II)] -(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ , , , )bis-[4,4',4''-(1,3,5-tri-methyl-benzene-2,4,6-tri-yl)tris-(hydrogen phenyl-phospho-nato-κ)]nickel(II) deca-hydrate.

The components of the title compound, [Ni(CHN)(HO)][Ni(CHN)(CHOP)]·10HO are two centrosymmetric [Ni(CHN)(HO)] dications, a centrosymmetric [Ni(CHN)(CHOP)] tetra-anion and five crystallographically unique water mol-ecules of crystallization. All of the nickel ions are coordinated by the four secondary N atoms of the macrocyclic cyclam ligands, which adopt the most energetically stable -III conformation, and the mutually O atoms of either water mol-ecules in the cations or the phospho-nate groups in the anion in a tetra-gonally distorted NiNO octa-hedral coordination geometry. Strong O-H⋯O hydrogen bonds between the protonated and the non-protonated phospho-nate O atoms of neighboring anions result in the formation of layers oriented parallel to the plane, which are linked into a three-dimensional network by virtue of numerous N-H⋯O and O-H⋯O hydrogen bonds arising from the -NH groups of the macrocycles, phospho-nate O atoms and coordinated and non-coordinated water mol-ecules.

Bis[3-(anthracen-9-yl)pentane-2,4-dionato-κ ,'](,-di-methyl-formamide-κ)[tris-(pyrazol-1-yl-κ )hydroborato]europium(III).

The title compound, [Eu(CHBN)(CHO)(CHNO)] or [TpEu(Anthracac)(DMF)], was synthesized by reaction of a tris-(pyrazol-yl)borate (Tp) Eu complex with 3-(anthracen-9-yl)pentane-2,4-dione (HAnthracac) in the presence of tri-ethyl-amine. In the title compound, Eu is located in an octa-vertex square-pyramidal coordination environment. In the two Anthracac ligands, the anthracene and nearly planar acetyl-acetonate fragments are almost orthogonal.

Crystal structure of a Tb-Cu glycine-hydroxamate 15-metallacrown-5 sulfate complex.

The core of the title complex, bis-[hexa-aqua-hemi-aqua-penta-kis-(μ-glycine-hydroxamato)sulfato-penta-copper(II)terbium(III)] sulfate hexa-hydrate, [TbCu(SO)(GlyHA)(HO)](SO)·6HO (), which belongs to the 15-metalla-crown-5 family, consists of five glycine-hydroxamate dianions (GlyHA; CHNO) and five copper(II) ions linked together forming a metallamacrocyclic moiety. The terbium(III) ion is connected to the centre of the metallamacrocycle through five hydroxamate oxygen atoms. The coordination environment of the Tb ion is completed to an octa-coordination level by oxygen atoms of a bidentate sulfate and an apically coordinated water mol-ecule, while the copper(II) atoms are square-planar, penta- or hexa-coordinate due to the apical coordination of water mol-ecules.

Crystal structures of Zn(cyclam)I (second monoclinic polymorph) and Zn(cyclam)I(I).

The asymmetric unit of the first title compound iodido-(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ , , , )zinc(II) iodide, [ZnI(CHN)]I, , consists of the zinc-cyclam macrocyclic cation with one iodide anion coordinated to the metal ion [Zn-I = 2.6619 (5) Å] and the second present as a counter-ion. The asymmetric unit of the second title compound iodido-(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ , , , )zinc(II) triiodide, [ZnI(CHN)]I, , consists of half of the centrosymmetric macrocyclic cation, in which the Zn ion coordinated to an iodide anion [Zn-I = 2.

Crystal structure of -di-aqua-(1,4,8,11-tetra-aza-undeca-ne)nickel(II) bis-(pyridine-2,6-di-carboxyl-ato)nickel(II).

The asymmetric unit of the title compound, -di-aqua-(1,4,8,11-tetra-aza-undecane-κ , , , )nickel(II) bis-(pyridine-2,6-di-carboxyl-ato-κ ,, )nickel(II) {[Ni()(HO)][Ni(pdc)] where = 1,4,8,11-tetra-aza-undecane (CHN) and pdc = the dianion of pyridine-2,6-di-carb-oxy-lic acid (CHNO )} consists of an [Ni()(HO)] complex cation and a [Ni(pdc)] anion. The metal ion in the cation is coordinated by the four N atoms of the tetra-amine ligand and the mutually O atoms of the water mol-ecules in a tetra-gonally elongated octa-hedral geometry with the average equatorial Ni-N bond length slightly shorter than the average axial Ni-O bond [2.087 (4) 2.

Crystal structure of [{[Ni(CHN)][Ni(CN)]}·2HO] , a one-dimensional coordination polymer formed from the [Ni(cyclam)] cation and the [Ni(CN)] anion.

The asymmetric unit of the title compound, -poly[[[(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ , , , )nickel(II)]-μ-cyanido-κ :-[bis-(cyanido-κ)nickel(II)]-μ-cyanido-κ :] dihydrate], {[Ni(CN)(CHN)]·2HO] or [{[Ni(CHN)][Ni(CN)]}·2HO] , consists of a pair of crystallographically non-equivalent macrocyclic cations and anions. The nickel(II) ions (all with site symmetry ) are coordinated by the four secondary N atoms of the macrocyclic ligands, which adopt the most energetically stable -III conformation, and the mutually N atoms of the tetra-cyano-nickelate anion in a slightly tetra-gonally distorted NiN octa-hedral coordination geometry. The [Ni(CN))] anion exhibits a bridging function, resulting in the formation of parallel polymeric chains running along the [10] direction.

Reductive Recyclization of sp-Enriched Functionalized Isoxazolines into α-Hydroxy Lactams.

An efficient synthesis (up to a 200 g scale) of 3-hydroxypyrrolidin-2-ones bearing alkyl substituents or functional groups at the C-5 position is described. The reaction sequence started from 1,3-dipolar cycloaddition of generated nitrile oxides with (meth-)acrylates into 3-substituted isoxazoline-5-carboxylates. The catalytic hydrogenolysis of the isoxazoline N-O bond was optimal upon using H (1 atm) at rt, with the following order of the catalyst activity: Pd-C > Pd(OH)-C > Pt-C.

Cadmium-Inspired Self-Polymerization of {LnCd} Units: Structure, Magnetic and Photoluminescent Properties of Novel Trimethylacetate 1D-Polymers (Ln = Sm, Eu, Tb, Dy, Ho, Er, Yb).

A series of heterometallic carboxylate 1D polymers of the general formula [LnCd(piv)(HO)]·nMeCN (Ln = Sm (), Eu (), Tb (), Dy (), Ho (), Er (), Yb (); piv = anion of trimethylacetic acid) was synthesized and structurally characterized. The use of Cd instead of Zn under similar synthetic conditions resulted in the formation of 1D polymers, in contrast to molecular trinuclear complexes with LnZn cores. All complexes - are isostructural.

Third Generation Buchwald Precatalysts with XPhos and RuPhos: Multigram Scale Synthesis, Solvent-Dependent Isomerization of XPhos Pd G3 and Quality Control by H- and P-NMR Spectroscopy.

The third generation Buchwald precatalysts Pd(ABP)(Phos)(OMs) (also known as Phos Pd G3)) with XPhos and RuPhos were prepared in multigram scale by a modified procedure (ABP = fragment of C-deprotonated 2-aminobiphenyl, XPhos = 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl, RuPhos = 2-dicyclohexylphosphino-2',6'-diisopropoxybiphenyl, OMs = CHSO). The H- and P-NMR spectra of the title complexes and some impurities, measured by various 1D and 2D techniques, were analyzed in detail. The solvent-dependent isomerization of Pd(ABP)(XPhos)(OMs) was studied by NMR, and the X-ray structures of two isomers were determined.

Rapid synthetic approaches to libraries of diversified 1,2-dihydrochromeno[2,3-c]pyrrole-3,9-diones and 3-(2-hydroxyphenyl)-4,5-dihydropyrrolo[3,4-c]pyrazol-6(1H)-ones.

An efficient and practical synthetic procedure for libraries of diversified 1,2-dihydrochromeno[2,3-c]pyrrole-3,9-diones using a multicomponent process is presented. A convenient synthetic procedure for obtaining functionalized 3-(2-hydroxyphenyl)-4,5-dihydropyrrolo[3,4-c]pyrazol-6(1H)-ones via ring-opening strategy has also been developed. This protocol was found to be compatible with a wide range of substituents and paves the way for the practical synthesis of title compounds with a broad range of substituents under mild condition.

Cu-Catalyzed Pyridine Synthesis via Oxidative Annulation of Cyclic Ketones with Propargylamine.

A Cu-catalyzed, easily scalable one-pot synthesis of fused pyridines by the reaction of cyclic ketones with propargylamine is described. The protocol was optimized based on the results of more than 30 experiments. The highest product yields were achieved in -PrOH as a solvent in the presence of 5.