P(i-BuNCH2CH2)3N: an efficient ligand for the direct alpha-arylation of nitriles with aryl bromides

A new catalyst system for the synthesis of alpha-aryl-substituted nitriles is reported. The bicyclic triaminophosphine P(i-BuNCH(2)CH(2))(3)N (1b) serves as an efficient and versatile ligand for the palladium-catalyzed direct alpha-arylation of nitriles with aryl bromides. Using ligand 1b, ethyl cyanoacetate and primary as well as secondary nitriles are efficiently coupled with a wide variety of aryl bromides possessing electron-rich, electron-poor, electron-neutral, and sterically hindered groups.     

Analysis of Five Pharmacologically Active Compounds from Rhodiola for Natural Product Drug Discovery with Capillary Electrophoresis

A rapid capillary electrophoresis method for the separation of five natural pharmacologically active compounds from extracted Rhodiola, namely salidroside, tyrosol, rhodionin, gallic acid and ethyl gallate has been developed. The separation of five natural pharmacologically active compounds was carried out in a fused-silica capillary with 14 mM boric acid, 30 mM SDS and 2.5% acetonitrile, adjusted to pH 10.7 with NaOH. Applied potential was 21kV. The temperature of the capillary was maintained at 25 °C by the instrument thermostating system, with the correlation coefficients of 0.9805–0.9989 for migration time, and relative standards of < 3.52% for peak areas. The established method is rapid and reproducible for the separation of five natural pharmacologically compounds from extracts of Rhodiola with satisfactory results.     

Synthesis and magnetic properties of the one-dimensional linear chain structure cyano-bridged complex [Cu(teta)(H2O)2][Cu(teta) Fe(CN)6]ClO4·2H2O (teta=5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacylotetradecane)

Reaction of either K₃[Fe(CN)₆] or K₄[Fe(CN)₆] with a macrocyclic Cu^II complex, [Cu(teta)](ClO₄)₂ (teta = 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacylotetradecane), in aqueous solution gave the same product as shown by spectroscopic and physicochemical characterisation. The crystal structure of the complex shows that it is a one-dimensional linear chain type heterobinuclear Fe^III–Cu^II polymer. The unit is composed of a [Cu(teta)(H₂O)₂]²⁺ cationic complex, a Fe^III–Cu^II alternate linear chain unit, a ClO ₄ ^– ion and four water molecules. The Cu atom is coordinated in a distorted octahedral arrangement by four nitrogen atoms from one teta ligand and two nitrogen atoms of the bridging cyanide groups. The Cu—N bond distances involving the cyanide bridges, 2.522(7) and 2.608(7)Å, respectively, indicate weak antiferromagnetic interactions between the Fe^III and Cu^II atoms.     

Tuning Ground States of Bis(triarylamine) Dications: From a Closed‐Shell Singlet to a Diradicaloid with an Excited Triplet State

Three bis(triarylamine) dications were isolated by using weakly coordinating anions. Their electronic structures in the ground state were investigated by various experiments in conjunction with theoretical calculations. The ground‐state electronic structures of these species were tunable by substituent effects, with two of them as closed‐shell singlets and one of them as an open‐shell singlet in the solid state. The excited state of the latter is thermally accessible, indicated by EPR and SQUID measurements. The work provides a new and stable diradicaloid structure motif with an excited triplet sate.     

Palladium‐Catalyzed Direct Cross‐Coupling of Carboranyllithium with (Hetero)Aryl Halides

A palladium‐catalyzed direct C‐arylation reaction of readily available cage carboranyllithium reagents with aryl halides has been developed for the first time. This method is applicable to a wide range of aryl halide substrates including aryl iodides, aryl bromides, and heteroaromatic halides.     

A simple and efficient algorithm for fused lasso signal approximator with convex loss function

We consider the augmented Lagrangian method (ALM) as a solver for the fused lasso signal approximator (FLSA) problem. The ALM is a dual method in which squares of the constraint functions are added as penalties to the Lagrangian. In order to apply this method to FLSA, two types of auxiliary variables are introduced to transform the original unconstrained minimization problem into a linearly constrained minimization problem. Each updating in this iterative algorithm consists of just a simple one-dimensional convex programming problem, with closed form solution in many cases. While the existing literature mostly focused on the quadratic loss function, our algorithm can be easily implemented for general convex loss. We also provide some convergence analysis of the algorithm. Finally, the method is illustrated with some simulation datasets.     

Deposition of a Continuous and Conformal Copper Seed Layer by a Large-Area Electron Cyclotron Resonance Plasma Source with Embedded Lisitano Antenna

To deposit copper seed layer on ultra large scale integration devices, a large-area (Ø 378 mm) electron cyclotron resonance plasma has been generated by using permanent magnets-embedded Lisitano antenna. The plasma source operates in the pressure range of 0.2–1.5 mTorr with microwave power range of 500–2,000 W. By using a Langmuir probe, the electron density and temperature have been measured near the DC sputter target position. Measurements indicate argon plasmas having electron densities of ~5 × 10¹⁰/cm and electron temperatures of 5 eV with 750 W microwave power at gas pressures of 0.5 mTorr. Using this plasma source and a DC sputter, we obtained excellent conformal copper seed layer with high aspect ratios of 12:1. This is in contrast with conventional methods using magnetron sputter, which has aspect ratios of 2–3:1. Also, improvements are observed in the smoothness (root mean square roughness of 1.345 nm), uniformity (2.5 % at 300 mm wafer), and sidewall symmetricity (more than 95 %) of the copper seed layer.     

Perylene Bisimide In-chain Polyethylene with Unique Self-assembly Nanostructure through Acyclic Diene Metathesis (ADMET) Polymerization

A novel perylene tetracarboxylic acid bisimide(PTCBI) in-chain polyethylene(PE) was first prepared via acyclic diene metathesis(ADMET) polymerization of PTCBI-functionalized α,ω-diene monomer. The polymers could spontaneously self-assemble into hollow cylindrical structures in which the π-π interaction between adjacent PTCBI moieties was enhanced and the electron mobility was possibly promoted. The hydrogenation of as-obtained polymer was readily accomplished, affording the desired precision PTCBI in-chain PE with a saturated backbone, which showed high glass transition temperature(Tg = 63 °C), relatively wide range of light absorption(λ = 200-575 nm), and higher LUMO level(-3.62 e V). It can therefore serve as a superior model for facile construction of functional polyolefin and soluble PTCBI polymer with ordered architecture.     

A class of finite groups with complete character degree graphs

In this paper, we construct a new class of finite groups whose common divisor graphs are complete graphs, while there is no prime dividing all the nontrivial degrees.