Ruthenium complexes with triazenide ligands bearing an N-heterocyclic moiety, and their catalytic properties in the reduction of nitroarenes.

A series of ruthenium complexes of formulae [RuCl(triazenide)(-cymene)] have been synthesized using as ligand a triazenide monofunctionalized with an N-heterocyclic moiety. Nuclear magnetic resonance, high resolution mass spectrometry and X-ray diffraction were used to characterize the triazenide ligands and their complexes. In addition, these ruthenium complexes catalyzed the reduction of nitrobenzene to aniline in the presence of sodium borohydride and ethanol as solvent at room temperature.

The effect of water molecules on paraquat salts: from physicochemical properties to environmental impact in the Brazilian Cerrado.

The green revolution model that is followed in the Brazilian Cerrado is dependent on mechanization, chemical fertilization for soil dressing and correction, and the use of herbicides. Paraquat is a methyl viologen herbicide marketed as bipyridylium dichloride salts and used (in low doses) to combat weeds in their post-emergence stage. It is a non-selective pesticide that causes the peroxidation of the lipids that make up the cell membrane, and when it comes into contact with foliage, it results in the death of the plant.

Bromine Substitution Effect on Structure, Reactivity, and Linear and Third-Order Nonlinear Optical Properties of 2,3-Dimethoxybenzaldehyde.

The structural and electronic properties of 2,3-dimethoxybenzaldehyde (2,3-DMB), 5-bromo-2,3-dimethoxybenzaldehyde (5-BRB), and 6-bromo-2,3-dimethoxybenzaldehyde (6-BRB) were extensively discussed with emphasis on linear and nonlinear optical responses. The intermolecular interactions were comparatively studied by Hirshfeld surfaces, quantum theory of atoms in molecules (QTAIM), and natural bond orbitals (NBOs), indicating that bromine substitution decreases the H···H and C···H contacts and increases H···Br and Br···Br closed-shell interactions on crystalline arrangements. The frontier molecular orbitals and molecular electrostatic potential map, carried out at the CAM-B3LYP/6-311++G(d,p) level of theory, showed that the kinetic stability occurs in the increasing order 6-BRB < 5-BRB < 2.

Chiral C -symmetric bis-thioureas as enzyme mimics in enantioselective Michael addition.

We report herein the synthesis and application of enantiopure C -symmetric primary amine-1,3-bis-thiourea organocatalysts in enantioselective conjugate 1,4-Michael addition of carbonyl containing nucleophiles, to nitroalkenes and N-phenylmaleimide, leading to final products in good enantioselectivities (up to 99%) and yields (up to 99%). We propose supramolecular noncovalent interactions within the organocatalyst's cleft between the substrate and the catalyst, via hydrogen bonding. Supramolecular interaction thus lowers the transition state energy mimicking an enzyme.

Mononuclear and Tetranuclear Copper(II) Complexes Bearing Amino Acid Schiff Base Ligands: Structural Characterization and Catalytic Applications.

Two new glycine-Schiff base copper(II) complexes were synthesized. Single crystal X-ray diffraction (SCXRD) allowed us to establish the structure of both complexes in the solid state. The glycine-Schiff base copper(II) complex derived from 2'-hydroxy-5'-nitroacetophenone showed a mononuclear hydrated structure, in which the Schiff base acted as a tridentate ligand, and the glycine-Schiff base copper(II) complex derived from 2'-hydroxy-5'-methylacetophenone showed a less common tetranuclear anhydrous metallocyclic structure, in which the Schiff base acted as a tetradentate ligand.

Midterm results and complications rates in vancouver type B2 and B3 periprosthetic femoral fractures treated with modular fluted tapered stems.

Unlabelled: Evaluate the mid-term success rate of these stems in periprosthetic femur fractures and to analyze the complications observed with the use of these stems.

Methods: Thirty five patients that underwent hip revision surgery secondary to Vancouver type B2 and B3 periprosthetic femur fracture were evaluated. In all cases, modular fluted tapered stems were used.

-[2-(3,4-Di-meth-oxy-phen-yl)-2-(phenyl-sulfan-yl)eth-yl]-2-(2-fluoro-phen-yl)acetamide.

The title compound, CHFNOS, is an inter-mediate in the synthesis of fluorine containing iso-quinoline alkaloids, which crystallizes in the triclinic space group with one mol-ecule in the asymmetric unit. The structure presents a racemic mixture of enanti-omers. The C-S-C-C torsion angle between the benzene ring system and the sulfonyl benzene ring is -178.

Novel Linezolid analogues with antiparasitic activity against Hymenolepis nana.

The stereoselective synthesis and anti- Hymenolepis nana activity of six Linezolid-type compounds, obtained by chemical modification of l-Alanine, are reported in this work. The synthetic strategy was to prepare diasteromeric N,N-dibenzylamino oxazolidinones 1 and 2, and coupling with 4-(4-bromophenyl)morpholine (3) to obtain N,N-dibenzylamino Linezolid analogues 4 and 5. A hydrogenolysis reaction over 4 and 5 resulted in amino-free Linezolid analogues 6 and 7, which were acetylated to reach diasteromeric Linezolid analogues 8 and 9.

Light up My Life: An Active Learning Lab to Elucidate Conductive Properties of Electrolytes.

Understanding molecular structure and its influence on chemical reactivity is a fundamental component in Chemistry curriculum. For example, acidic protons ionize, or ionic solids dissociate to form charge, inducing electrolyte properties depending on molecular structure. An active learning lab is designed to demonstrate connection between electrolyte behavior and structure of various molecules.

C -symmetric sulfonamides as homogeneous and heterogeneous organocatalysts that mimic enzymes in enantioselective Michael additions.

Herein, we report the synthesis of C -symmetric sulfonamides as homogeneous and heterogeneous organocatalysts and their application in the enantioselective conjugate 1,4-Michael addition of carbonylic nucleophiles to β-nitrostyrene. Organocatalysts hydrogen bond to β-nitrostyrene and enamine in the transition state, mimicking an enzyme leading to final products in high yields (up to 98%) and good enantioselectivities (up to 96%). In addition, these results were supported by density functional calculations.

Crystal structure of ethyl 2,4-di-chloro-quinoline-3-carboxyl-ate.

In the crystal structure of the title compound, C12H9Cl2NO2, the mean planes through the quinoline and carboxyl-ate groups have r.m.s.

Experimental FT-IR, Laser-Raman and DFT spectroscopic analysis of 2,3,4,5,6-Pentafluoro-trans-cinnamic acid.

In this study, the experimental and theoretical vibrational frequencies of a newly synthesized 2,3,4,5,6-Pentafluoro-trans-cinnamic acid have been investigated. The experimental FT-IR (4000-400 cm(-1)) and Laser-Raman spectra (4000-100 cm(-1)) of the molecule in solid phase have been recorded. The theoretical vibrational frequencies and optimized geometric parameters (bond lengths and bond angles) have been calculated by using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr) and DFT/M06-2X (the highly parameterized, empirical exchange correlation function) quantum chemical methods with 6-311++G(d,p) basis set by Gaussian 09W software, for the first time.

4-Hy-droxy-6-methyl-pyridin-2(1H)-one.

In the crystal structure of the title compound, C6H7NO2, N-H⋯O and O-H⋯O hydrogen bonds link the mol-ecules, forming a zigzag array along [001] and a layer structure parallel to the ab plane.

2,3,4,5,6-Penta-fluoro-trans-cinnamic acid.

The title compound, C9H3F5O2, crystallizes as O-H⋯O hydrogen-bonded carb-oxy-lic acid dimers that, together with C-H⋯F inter-actions and O⋯F [2.8065 (13) and 2.9628 (13) Å] and F⋯F [2.

(2-tert-Butyl-5-hy-droxy-methyl-1,3-dioxan-5-yl)methanol.

In the title compound, C(10)H(20)O(4), the dioxane ring adopts a chair conformation. The tert-butyl group occupies an equatorial position, and is staggered with respect to the O atoms of the dioxane ring. In the crystal, mol-ecules are connected by O-H⋯O hydrogen-bonds into zigzag chains of R(4) (4)(8) and R(2) (2)(12) ring motifs that run parallel to the a axis.

2,4,5-Tris(pyridin-4-yl)-4,5-dihydro-1,3-oxazole.

In the title compound, C(18)H(14)N(4)O, the mol-ecules are disordered about a crystallographic twofold axis, leading to 50:50 disorder of the O- and N-atom sites within the oxazole ring. As a consequence, symmetry-related oxazole C-N and C-O bonds are averaged. The oxazole ring makes a dihedral angle of 6.

1,3,5-Tris(pyridin-3-yl)-2,4-diaza-penta-1,4-diene.

In the solid state, the structure of the title compound, C(18)H(15)N(5), is stabilized by weak C-H⋯N interactions. Mol-ecules are arranged in layers parallel to the bc plane forming an inter-esting supra-molecular structure.

1-Benzyl-4-(naphthalen-1-yl)-1H-1,2,3-triazole.

In the title compound, C(19)H(15)N(3), the benzyl group is almost perpendicular to the triazole ring [dihedral angle = 80.64 (8)°], while the napthyl group makes an angle of 30.27 (12)° with the plane of the triazole ring.

Asymmetric transfer hydrogenation of prochiral ketones in aqueous media with chiral water-soluble and heterogenized bifunctional catalysts of the RhCp*-type ligand.

Asymmetric transfer hydrogenation (ATH) of prochiral aromatic ketones was carried out with a water-soluble complex of Rh(III)Cp* and mononitrobenzenesulfonamide bidentate ligand (1R,2R)-N-(2-aminocyclohexyl)-4-nitrobenzenesulfonamide 1 derived from chiral cyclohexane-1,2-diamine. Aqueous sodium formate was used as the hydride source. The reaction afforded the chiral alcohols in good enantioselectivities (79-93%) and yields (>99%).

Benzene-1,3,5-triyl tris-(methane-sulfonate).

In the mol-ecule of the title compound, C(9)H(12)O(9)S(3), the two methanesulfonate groups re located one above and one below the ring plane. The C-O-S angle range is 119.3 (2)-121.

N-(2-Hydroxy-ethyl)-2-[3-(p-tol-yl)triazen-1-yl]benzamide.

In the solid state, the structure of the title compound, C(16)H(18)N(4)O(2), is stabilized by inter-molecular N-H⋯O and O-H⋯O hydrogen bonds. These hydrogen bonds arrange the mol-ecules into a double-layer supra-molecular structure. The mol-ecular conformation is is consolidated by an intra-molecular N-H⋯N hydrogen bond.

Through-space interactions between parallel-offset arenes at the van der Waals distance: 1,8-diarylbiphenylene syntheses, structure and QM computations.

A model for studying polar-pi interactions between arenes spaced at van der Waals distances is developed on the basis of peri-diarylbiphenylenes. A set of 1,8-diarylbiphenylenes is synthesized comprising two Hammett series, one with reference to mesityl ring interactions and the other with reference to pentafluorophenyl ring interactions. X-Ray crystal structures of several derivatives are determined.

Synthesis of analogs of amathamide A and their preliminary antimicrobial activity.

Syntheses of three non-brominated analogs of amathamide A (1), a natural alkaloid isolated from the Tasmanian marine bryozoan Amathia wilsoni, are described. Antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomona aeruginosa, and Candida albicans was tested. Test results for amathamide A (1) showed a weak activity against C.