Palladium-catalyzed transformation of cyclobutanone O-benzoyloximes to nitriles via C-C bond cleavage

Palladium-catalyzed transformation of cyclobutanone O-benzoyloximes to a variety of nitriles is described. The reaction may proceed via two important steps, that is, (i) oxidative addition of the N-O bond of oximes to Pd(0) to give a cyclobutylideneaminopalladium(II) species and (ii) beta-carbon elimination of this species to afford a reactive alkylpalladium species. The kind of products is very dependent on the nature of substituents on the cyclobutane ring. The direction of the C-C bond cleavage is controlled by the kind of ligand employed. The sequential reaction composed of the C-C bond cleavage and the subsequent intra- and intermolecular C-C bond formations via the corresponding alkylpalladium species is also demonstrated. For example, an oxime having an alkynyl moiety at a suitable position reacts with a variety of alkenes to afford nitriles bearing dienylcyclopentane moiety in moderate to good yields.     

Total-reflection X-ray fluorescence analysis for semiconductor process characterization

Semiconductor process characterization techniques based on total-reflection X-ray fluorescence (TXRF) analysis are reviewed and discussed. One of the most critical factors in obtaining reliable determinations by TXRF is the reliability of the standard samples that are used. Conventional physisorption standard samples such as spin coat wafers have two potential drawbacks: reproducibility of depth profile and stability. A method of chemisorption called ‘immersion in alkaline hydrogen peroxide solution (IAP)’ was proposed that provides answers to these two problems. IAP standard samples were used to experimentally examine three methods of TXRF application: Straight-TXRF, VPD-TXRF, and Sweeping-TXRF. In the application of Straight-TXRF, the linearity of Cu at a level of 10⁹ atoms cm⁻² is examined. In the application of VPD-TXRF, test results of VPD-TXRF for both transition metals and light elements are shown. Finally, a new measurement protocol called Sweeping-TXRF is proposed to conduct whole-surface analysis without chemical preconcentration.     

Muon spin resonance by strong pulsed r.f. field with pulsed muons

Muon spin resonance experiments have been performed for the ⁺ in H₂O and for some other cases, and the first observation has been made of the time-differential pattern of muon spin resonance, namely, spin precession around the r.f. field vector under various resonance conditions. In the present experiment, a high-power pulsed r.f. field was effectively applied to the pulsed muon beam in our laboratory of the KEK-Booster Meson Facility (BOOM). Potential uses of muon spin resonance, particularly for research in the border regions of solid state and nuclear physics, are discussed in comparison with the conventional spin rotation method.     

Zero- and low-field μ+ spin relaxation behavior in MnSi

Conclusion As is demonstrated in the present work, the zero-field technique is a powerful method in studying diffusion/trapping of the ⁺, especially for the case of slow hopping. In the case of MnSi, the hopping time _c has been determined to be longer than 20 sec, with the width of the nuclear random fields / = 3.80 ± 0.4 Oe. The role of the ⁺ in low-field relaxation studies is unique, since it provides information inaccessible to NMR techniques.Work supported by Japan Society for the Promotion of Science, the Toray Science Foundation, the Grant-in-Aid of the Japanese Ministry of Education, Culture and Science, and the Atomic Energy Control Board and National Research Council of Canada.     

Quadruple-layered perovskite (CuCl)Ca2NaNb4O13

We will present the synthesis, structure and magnetic properties of a new quadruple-layered perovskite (CuCl)Ca₂NaNb₄O₁₃. Through a topotactic ion-exchange reaction with CuCl₂, the precursor RbCa₂NaNb₄O₁₃ presumably having an incoherent octahederal tliting changes into (CuCl)Ca₂NaNb₄O₁₃ with a 2a_p×2a_p×2c_p superstructure (tetragonal; a=7.73232(5) Å, c=39.2156(4) Å). The well-defined superstructure for the ion-exchanged product should be stabilized by the inserted CuCl₄O₂ octahedral layers that firmly connect with neighboring perovskite layers. Magnetic studies show the absence of long-range magnetic ordering down to 2 K despite strong in-plane interactions. Aleksandrov′s group theory and Rietveld refinement of synchrotron X-ray diffraction data suggest the structure to be of I4/mmm space group with in-phase tilting along the a and b axes, a two-tilt system (++0).     

Generalized positive continuous additive functionals of multidimensional Brownian motion and their associated Revuz measures

We extend the notion of positive continuous additive functionals of multidimensional Brownian motions to generalized Wiener functionals in the setting of Malliavin calculus. We call such a functional a generalized PCAF. The associated Revuz measure and a characteristic of a generalized PCAF are also extended adequately. By making use of these tools a local time representation of generalized PCAFs is discussed. It is known that a Radon measure corresponds to a generalized Wiener functional through the occupation time formula. We also study a condition for this functional to be a generalized PCAF and the relation between the associated Revuz measure of the generalized PCAF corresponding to Radon measure and this Radon measure. Finally we discuss a criterion to determine the exact Meyer–Watanabe’s Sobolev space to which this corresponding functional belongs.