Electrodeposition of Ni–Fe alloy from a choline chloride-containing ionic liquid

Journal of Solid State Electrochemistry - The electrochemical deposition of a nickel–iron alloy from a plating solution based on a deep eutectic solvent (a eutectic mixture of ethylene glycol...     

On a Polynomial Fractional Formulation for Independence Number of a Graph

In this paper we characterize the local maxima of a continuous global optimization formulation for finding the independence number of a graph. Classical Karush-Kuhn-Tucker conditions and simple combinatorial arguments are found sufficient to deduce several interesting properties of the local and global maxima. These properties can be utilized in developing new approaches to the maximum independent set problem.     

2,3,4,5,6‐Penta­nitro­aniline 1,2‐dichloro­ethane disolvate: `push–pull' deformation of aromatic rings by intra­molecular charge transfer

The title compound, C₆H₂N₆O₁₀·2C₂H₄Cl₂, forms layered stacks of penta­nitro­aniline mol­ecules, which possess twofold symmetry. The voids between these stacks are occupied by dichloro­ethane mol­ecules, which reside near a 2/m symmetry element and display pseudo‐inversion symmetry. The C atoms in one of the two solvent mol­ecules are threefold disordered. In the penta­nitro­aniline mol­ecule, considerable distortion of the benzenoid ring, coupled with the short C—N(H₂) bond and out‐of‐plane NO₂ twistings, point to significant intra­molecular `push–pull' charge transfer at the amino‐ and nitro‐substituted (ortho and para) positions, as theoretically quantified by natural bond orbital analysis of the π‐electron density.     

General Base Catalysis by Organic Bases of the Reaction of Diphenylphosphinic Hydrazide with Phenyl Isocyanate in Benzene

The kinetics of the reaction of diphenylphosphinic hydrazide with phenyl isocyanate in the presence of organic bases in benzene at 25°C were studied. The catalytic activity of the bases correlates with spectroscopic and thermodynamic Taft (pK _{H B}), Koppel-Palm (B), and Gutmann (DN) parameters. A common general base mechanism of the catalysis of semicarbazide formation by bases belonging to different classes of organic compounds is offered and discussed.     

Two-level structured self-adaptive surfaces with reversibly tunable properties

We report a route to fabricate two-level structured self-adaptive surfaces (SAS) of polymer materials. The first level of structure is built by a rough polymer film that consists of needlelike structures of micrometer size. The second level of structure is formed by the nanoscopic self-assembled domains of a demixed polymer brush irreversibly grafted onto the needles. By exposing the surface to solvents that are selective to one of the components of the brush, we reversibly tune the surface properties. The large-scale surface structure amplifies the response and enables us to control wettability, adhesion, and chemical composition of the surface over a wide range.     

Organic solvents as catalysts of formation of phosphorus-containing thiosemicarbazides

The kinetics of the reaction of O,O-diphenyl phosphorohydrazidothioate with phenyl isothiocyanate at 25°C in benzene in the presence of organic bases is studied. The dependences of the catalytic activity on the nature and structure of organic bases and on various parameters characterizing their basicity are analyzed. The catalytic activity exhibited in the formation of phosphorus-containing thiosemicarbazides by donor solvents added to benzene correlates well with both spectroscopic and thermodynamic parameters of basicity: Taft (pK _HB), Koppel-Palm (B), and Gutmann (DN) parameters. A common mechanism of the base catalysis of the thiosemicarbazide formation by organic bases of different classes is suggested and discussed.     

Effect of reaction medium on the kinetic rules of formation of phosphorus-containing picrylhydrazides

Rate constants of the reaction of diphenylphosphinic acid hydrazide with picryl chloride in the solvents of different nature may be quantitatively connected with their physicochemical characteristics by means of the linear tetraparametric Coppel-Palm equation. The rule obtained permits to carry out quantitative analysis of the solvatational effects of solvents under study. Reaction rate depends mainly on the solvent basicity and polarity. Reaction mechanism is discussed and possible scheme of solvatation is offered.     

Nanosensors based on responsive polymer brushes and gold nanoparticle enhanced transmission surface plasmon resonance spectroscopy

Swelling (and shrinking) of poly(2-vinylpyridine), P2VP, polymer brushes, caused by pH changes, could be readily monitored by transmission surface plasmon resonance, T-SPR, spectroscopy. Gold nanoparticles attached to the P2VP polymer brushes dramatically enhanced the pH-induced shift in the T-SPR absorption spectra. (A 50 nm shift of the absorption maximum of the T-SPR spectrum of the supporting gold nanoislands was observed upon changing the pH from 5.0 to 2.0, corresponding to a swelling of the polymer brushes from 8.1 +/- 0.7 to 24.0 +/- 2.0 nm. Same shift in the opposite direction was observed upon changing the pH from 2.0 to 5.0.)