Target Residues from the Interaction of Copper with 40MeV/u 40Ar Ions

Cross Sections and average forward recoil range FW were measured for target residues from the interaction of Cu with 40MeV/u ⁴⁰Ar ions using off-line y-ray spectroscopy.The mass yield distribution was obtained with assumption of charge distribution.The linear momentum transfer was calculated from FW values.A comparison with similar results of ¹²C+Cu and ²⁰Ne+Cu reactions indicates that the fractional linear momentum transfer,corresponding to central collisions,decreases with increasing projectile mass at the same energy per nucleon. However,the excitation energy of the composite system created from the collisions of Cu with ⁴⁰Ar ions reached the value of 5.3MeV /u and was higher than those from the collisions with ¹²C and ²⁰Ne ions.     

Demonstration of isospecific free radical polymerization of acrylate controlled by conformation and chirality of monomer

Radical polymerization of lactic acid‐based chiral and achiral methylene dioxolanones, a model for conformationally s‐cis locked acrylate, was carried out with AIBN to demonstrate an isospecific free radical polymerization controlled by chirality and conformation of monomer. Polymerization of the dioxolanones proceeded smoothly without ring opening to give a polymer with moderate molecular weight and 100% of maximum isotacticity. ESR spectrum indicated a twisted conformation of the growing poly(methylene dioxolanone) radical in contrast to an acyclic analogous radical, suggesting a restriction of the free rotation around main chain C_α? C_β bond of the growing radical center. Chirality as well as the polarity and bulkiness of monomer affected the polymer tacticity, and chiral alkyl substituent would afford a high isotactic polymer, in which higher the enantiomeric excess of the monomer was, higher the isotacticity of the polymer was. While, achiral or polar substituents including dibenzyl and trichloromethyl groups would afford an atactic polymer. In addition, glass transition temperature (T_g) of the resulting polymers was significantly high, ranging from 172.2 to 229.8 °C, and even for an isotactic polymer T_g was as high as 206.8 °C. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2007–2016     

Synthesis of hyperbranched polyacetals via an + b2‐type polyaddition (n = 3, 8, 18, and 21): Candidate resists for extreme ultraviolet lithography

Polyaddition (A_n + B₂) reactions of 1,1,1‐tris(4‐hydoxyphenyl) ethane (THPE; A₃‐type monomer), calix[4]resorcinarene (CRA[4]; A₈‐type monomer), α‐cyclodextrin (α‐CD; A₁₈‐type monomer), and β‐cyclodextrin (β‐CD; A₂₁‐type monomer) with 1,4‐bis(4‐vinyloxy)cyclohexane (BVOC; B₂‐type monomer) afforded corresponding soluble hyperbranched polyacetals. The physical properties, including solubility, thermal stability, and film‐forming ability, the ultraviolet‐induced degradation reactivity, and the solubility‐switch in an extreme ultraviolet (EUV) exposure tool indicated that poly(THPE‐co‐BVOC) and poly(CRA[4]‐co‐BVOC) are candidate next‐generation photo‐resists. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2343–2350     

Chiral phenylazomethine cage

Enantiopure phenylazomethine cages ((S)- and (R)-PAC) were selectively obtained by one-pot dehydration of chiral (S)- and (R)-syn-tris(norborneno)benzene with p-phenylenediamine in moderate yields (56% and 50%), respectively. The structure and chirality of PACs in solution and solid state were confirmed by NMR, CD, X-ray diffraction and DFT calculations.     

Effects of water content on magnesium deposition from a Grignard reagent-based tetrahydrofuran electrolyte

It is well known that water causes decomposition of Grignard reagents. When these reagents are used, water or moisture should be eliminated. However, it is possible that a very small amount of water, for example, trapped in the walls of the glassware used, can enter the system even in a well-controlled Ar glove box. Therefore, in this work, the effect of very low concentrations of water on Mg deposition from a Grignard reagent-based electrolyte was studied. It was shown that a minute amount of water, although insufficient to cause destruction of the Grignard reagent, affects the overpotential for Mg deposition, resulting in Mg deposits of different morphology. For reproducible and reversible Mg deposition and dissolution, it is desirable that the water content of the electrolyte is kept as low as possible and the electrolyte is left to stand for at least several hours after preparation.     

149Sm and 57Fe nuclear resonant inelastic scattering of filled skutterudites SmFe4X12 (X: pnictogen)

¹⁴⁹Sm and ⁵⁷Fe nuclear resonant inelastic scattering (NRIS) measurements were carried out on SmFe₄P₁₂, SmFe₄As₁₂ and SmFe₄Sb₁₂. A clear dip structure of the ⁵⁷Fe NRIS spectrum was found in SmFe₄P₁₂, which was not clearly observed for SmFe₄As₁₂ and SmFe₄Sb₁₂. On the other hand, the line width of the phonon excitation in the ¹⁴⁹Sm NRIS spectrum increases with increasing the ionic radius of the pnictogen. These findings imply that the hybridization between the Sm and Fe phonon modes is correlated to changes in the ionic radius of the pnictogen.     

Synthesis of cyanofuroxans from 4-nitrofuroxans via CC bond forming reactions

A substitution reaction of 4-nitrofuroxans to prepare 4-cyanofuroxans is described. This substitution reaction was complicated by the reverse reaction and a judicious choice of cyanide source was important to enable this direct synthesis process. The optimized reaction conditions showed an excellent applicability for the synthesis of a range of 4-cyanofuroxans. 3-Cyanofuroxans, known to be thiol-mediated nitric oxide donors, could also be obtained by the thermal or photochemical isomerization of 4-cyanofuroxans. The developed cyanation of furoxans is a rare example of CC bond-forming reaction on a furoxan ring.