Thermodynamics of aqueous mixtures of nonelectrolytes. IV. Excess volumes of water-acetonitrile mixtures from 15 to 35°C

Excess volumes of water-acetonitrile mixtures were obtained from measurements of density over the entire mole fraction range and at 5 degree intervals from 15 to 35°C. Partial molar excess volumes at the five temperatures, excess coefficients of thermal expansion at 25°C and partial molar excess expansibilities at 25°C were derived from the results. The values of the various volumetric properties are compared with data from the literature.Issued as NRCC No. 19500     

Approaches to syn-7-substituted 2-azanorbornanes as potential nicotinic agonists; synthesis of syn- and anti-isoepibatidine

[reaction: see text] Coupling of N-Boc-7-bromo-2-azabicyclo[2.2.1]heptane with aryl and pyridyl boronic acids incorporates aryl and heterocyclic substituents at the 7-position and leads to a preference for syn over anti stereoisomers. Incorporation of a chloropyridyl group followed by N-deprotection gives syn-isoepibatidine. Facial selectivity in attack on 7-keto-2-azanorbornanes depends heavily on the N-protecting group leading to the first syn-7-hydroxy-2-azabicyclo[2.2.1]heptane derivative.     

A new procedure for preparation of carboxylic acid hydrazides

The standard method for preparing carboxylic acid hydrazides is hydrazinolysis of esters in alcoholic solutions. However, when applied to alpha,beta-unsaturated esters, the main product typically is the pyrazolidinone resulting from an undesired Michael-type cyclization. Other alternative methodologies reported for direct preparation of hydrazides from acids are inefficient. We developed an efficient and general process, involving preforming activated esters and/or amides followed by reaction with hydrazine, for the preparation of hydrazides including those of alpha,beta-unsaturated acids. This process gives the desired hydrazides in excellent yield and purity under mild conditions.     

Introduction of peroxide groups onto carbon black surface by radical trapping and radical graft polymerization of vinyl monomers initiated by the surface peroxide groups

The introduction of peroxide groups onto carbon black surface was achieved through the trapping of the peroxide radicals formed by the decomposition of polymeric peroxide, such as poly(tetraethylene glycol peroxyadipate) (ATPPO), and bis-peroxide, such as 1,1′-bis (t-butyldioxy)cyclohexane (Perhexa-C), by the surface: the amount of peroxide groups introduced onto carbon black surface by the treatment with ATPPO and Perhexa-C were determined to be 0.07 mmol/g and 0.12 mmol/g, respectively. The polymerization of vinyl monomers with positive e-value, such as methyl methacrylate and 2-hydroxyethy methacrylate, was successfully initiated by the peroxide groups introduced onto carbon black surface. During the polymerization, the corresponding polymers were effectively grafted onto the surface as a result of the propagation of polymer from the surface radicals formed by decomposition of the peroxide groups. The polymerization of vinyl monomers with negative e-value, such as styrene and vinyl acetate, however, was scarcely initiated by the peroxide groups on carbon black. This may be due to the fact that surface active radicals, which were formed by the hydrogen abstraction from carbon black by fragment radicals, inhibit the polymerization of vinyl monomers with negative e-value. © 1996 John Wiley & Sons, Inc.     

Monocular visual acuity measured with the OccluPad binocular vision test in patients with unilateral functional visual loss

Optical Review - This study used two different testing methods to examine vision in pediatric patients suspected of unilateral functional vision loss. Monocular vision in the affected eye was...     

Studies on the synthesis of apoptolidin A. 1. Synthesis of the C(1)-C(11) fragment

A synthesis of the C(1)-C(11) fragment of apoptolidin A has been accomplished by a convergent route involving the stereoselective glycosidation of 9 and the Suzuki cross-coupling reaction of bromodienoate 7 and the vinylborane generated via chemoselective hydroboration of diyne 6 with diisopinocampheylborane.     

A novel donor–donor polymeric dyad of Poly(3‐hexylthiophene‐block‐oligo(anthracene‐9,10‐diyl): Synthesis,solid‐state packing,and electronic properties

A new polymeric dyad of oligo‐anthracene‐block‐poly(3‐hexylthiophene) (Oligo‐ANT‐b‐P3HT) has been synthesized as a donor–donor dyad building block for organic photovoltaics. The polymer dyad and oligomer of anthracene‐9,10‐diyl (Oligo‐ANT) are prepared by Grignard Metathesis. The higher order of crystallinity and molecular chains ordering at solid phase reveal the intrinsic optical and electrical properties of polymeric dyad resulting in relatively higher light harvesting ability compared to the oligo(anthracene‐9,10‐diyl). The UV‐visible spectrum of (Oligo‐ANT‐b‐P3HT) in solution shows broad absorption with two sets of absorption from both anthracene and thiophene core units, covering a wide range of the visible spectrum. The test devices of the blends of polymeric dyad with fullerene C₆₁ (PCBM) show improved photovoltaic performance with a power conversion efficiency of 3.26% upon subjecting to pre‐fabrication thermal treatments. With optimized morphology of the interpenetrating network and the shorter fluorescence lifetime of the annealed dyad/PCBM blends, the effective charge transfer from the donor dyad to PCBM has evidenced. Thus, these studies will allow further synthetic advances to make potential high crystalline polymeric dyads with significantly improved light harvesting capability. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3032–3045     

Determination of nitrogen in UN,PuN and (U,Pu)N by oxidation in circulating oxygen and gas chromatographic measurement of the combustion gases

A simple and accurate method for the determination of nitrogen in uranium- and plutonium-bearing materials was developed. The loss of nitrogen by oxidation of the sample before analysis was prevented by pulverizing, weighing and packing the sample into a tin capsule in a glove-box with a high-purity argon atmosphere. Nitrogen was determined by oxidizing the nitrides in the tin capsule in circulating oxygen at 850 °C and analysing the combustion gases by gas chromatography with thermal conductivity detection. The relative standard deviation was about 0.7% and the time required to analyse one sample was about 10 min for successive analyses. Skilled techniques for glove-box work are not necessary. The method is applicable not only to the analysis of research samples but also to the quality control of nitride fuel production lines.     

Deposition of Diamond-Like Carbon Film in a Closed-Space CH4 RF Plasma

Deposition of diamond-like carbon (DLC) film and mass spectrometry measurements were carried out in a closed-space CH₄ rf (13.56 MHz) plasma (without both gas injection and vacuum pumping during the process). At pressures less than 0.6 Torr, the thickness of the DLC film deposited increased with increasing elapsed deposition time, and reached a maximum value, but after this the film thickness started to decrease, which was considered to be caused predominantly by ion-induced sputter etching. The maximum film thickness appeared at larger elapsed time for higher deposition pressure. The mass concentrations of hydrocarbon ions indicated anomalous behavior at early deposition times, but those of higher hydrocarbon ions are clearly increased at the point where the film thickness started to decrease. These results suggested that the ratio of precursor CH₃al density to the total hydrocarbon ion density (_CH3/_ion in the CH₄a was an important factor for the carbon film formation, and when this ratio reduced to a certain critical value with increasing elapsed deposition time, the deposited film was then re-etched predominately by the secondary higher hydrocarbon ions. At 1.0 Torr where a polymer-like soft carbon film was deposited, such re-etching of the deposited film was not observed.