Chiral Interlocked Corrole Dimers Directly Linked at Inner Carbon Atoms of Confused Pyrrole Rings

A facile synthetic strategy towards conformationally stable chiral chromophores based on dimeric porphyrinoids has been established. A peculiar class of face-to-face intramolecularly interlocked corrole dimers were formed by the oxidative C−C coupling linked at the inner carbon sites upon simple treatment of copper(II) ions. Their intrinsic electronic structures were modulated by the peripheral corrole ring annulations, which lead to distinct optical properties and redox profiles. The stereogenic carbon centers implemented in the confused corrole skeleton provided a rationale for designing novel chiral materials.     

Convergence in [2+2+2] synthesis of β-phenylnaphthalene motif in polyaromatic natural products

Two optional routes to β-phenylnaphthalene structure are developed by introducing α- and β-styryl groups onto different positions in the benzocyclobutene ring followed by ring enlargement.     

Status of heavy element research using a gas-filled recoil separator at RIKEN

A gas-filled type of recoil separator for heavy element research was installed at an experimental hall of RIKEN Linear Accelerator facility to realize getting higher intensity of primary beam and long beam time. Performance of the separator was studied using target recoils and various nuclear reactions. The results show the high performance of the separator for heave element research. As an application of the GARIS, production and identification of an isotope of the 110th element ²⁷¹[110] have been performed using the ²⁰⁸Pb(⁶⁴Ni,1n)²⁷¹[110] reaction. Three decay chains coincide well both in decay times and energies with the ones reported by the group of SHIP experiment at GSI, Germany. Our results provide a confirmation of the synthesis of an isotope ²⁷¹[110] of element 110.     

Structural characterization of polypyrrole in the solid state by high resolution 15N NMR spectroscopy [II]

The solid-state ¹⁵N CP/MAS NMR spectra and ¹⁵N spin-lattice relaxation times (T₁) of doped and dedoped ¹⁵N-labeled polypyrroles prepared by electrochemical polymerization, have been measured by means of high-resolution solid-state ¹⁵N NMR. The ¹⁵N signal of polypyrrole consists of four peaks decomposed by line shape analysis. The four peaks obtained have been assigned to the various structures of polypyrrole. Further, the half-width of the ¹⁵N NMR spectra of polypyrroles is discussed as related to the electrical conductivity. © 1995 John Wiley & Sons, Inc.     

Curved Ferroelectric Liquid Crystal Matrix Displays Driven by Field-Sequential-Color and Active-Matrix Techniques

This paper describes a curved field-sequential-color matrix display using fast-response ferroelectric liquid crystal. Black matrix and transparent electrode patterns were formed on a thin plastic substrate by a transfer method from a glass substrate. While a composite film of liquid crystal and micro-polymers of walls and fibers was formed between the flexible substrates by printing, laminating and curing processes of a solution of monomers and liquid crystal, the mechanical stability was enhanced by use of multi-functional monomers to form large display panels. The image pixels of the matrix panel were driven by an active matrix scheme using an external switch transistor array at a frequency of 180 Hz for intermittent three-primary-color backlight illumination. The flexible A4-paper-sized color display with 24 × 16 pixels and 60 Hz field frequency was demonstrated by illuminating it with sequential three-primary-color lights from light-emitting diodes of the backlight. Our display system is useful in various information displays because of its freedom of setting and location.     

A precision measurement of the hyperfine structure of87Sr+

The ground state hyperfine splitting of⁸⁷Sr⁺ was measured with a precision of 1×10^–8. The experiments were performed with an RF ion trap connected to an ISOL (isotope separator on-line), where all the possible transitions between Zeeman sublevels were observed by a laser-microwave double resonance method. The magnetic dipole hyperfine constant was determined to beA=–1 000 473.673 (11) kHz.     

Development and features of hydro-membrane gas chromatography.

Hydro-membrane gas chromatography (HMGC) is achieved by the annular condensation of water in a capillary column at less than 70 degrees C. The annular membrane of water is formed as a result of the wettability of the stationary phase, which is induced at a water contact angle ranging from 75 degrees to 79 degrees, as derived from a solubility parameter (delta) range of 15.7 +/- 0.3 MPa(1/2) of the coated resin. The range of the liquid to gas volume ratio (beta) required to support the annular membrane should be kept between 0.00005 and 0.0003. In the case of a 0.25-mm i.d. column, the ratio can be set by the combination of a 0.1 to 0.2 microl min(-1) water supply rate and helium gas flow rate. Separation by HMGC develops not only a gas-solid partition but also a focusing effect on the water membrane. One feature of HMGC is that it gives a non-adsorption chromatogram based on the blocking effect of pre-adsorbed water; furthermore, despite the presence of a relatively large quantity of water, the electron impact ionization efficiency is kept the same as in the usual GC/MS condition. The detection limit with the injection of 1 microl of aquatic solution was estimated to be less than 0.1 ppb of low-molecular-weight fatty acids with s/n = 5 on a mass chromatogram at m/z 45. The HMGC/EI-MS system can be applied to the trace analysis of C1 to C3 volatile acids, volatile inorganic acids, and halogenated organic acids in water.     

A convergent approach to the formal total synthesis of hemibrevetoxin B

A convergent synthesis of the key synthetic intermediate of hemibrevetoxin B was achieved via the intramolecular allylation of an α-chloroacetoxy ether and subsequent ring-closing metathesis.     

A compact optical heterodyne interferometer by optical integration and its application

A compact high-resolution optical heterodyne interferometer combining a two-frequency light module and a minute optical system is described. The light module, which generates two independent frequencies of light, is fabricated by proton exchange method on LiNbO₃ substrate. We report an experiment evaluating measurement accuracy using a micro-displacement measurement system which incorporates this interferometer. Results of the experiment with a standard thickness sample show high thermal stability with maximum measurement error of 1.8 nm at a temperature from 19°C to 33°C. The system was used to measure the hysteresis of a piezoelectric element for displacements of several nm, thereby making it possible to analyze the system quantitatively in practice.