Hyperspherical slow variable discretization method for weakly bound triatomic molecules

We develop a method for calculating the bound state energies and the wave functions of weakly bound triatomic molecular systems. The method is based on the use of hyperspherical coordinates, combined with the slow variable discretization approach. The finite-element methods-discrete variable representation scheme provides an efficient means to solve the coupled-channel hyper-radial equations. Our method is applied to searching for bound states of the (20)Ne(2)H and (4)He(20)NeH triatomic molecules, using the best empirical pairwise interaction potentials. We consider not only zero total nuclear orbital momentum, J = 0, states but also J > 0 states. The (20)Ne(2)H system has been found to possess one bound state each for the J(Π)=0(+),1(-), and 2(+) symmetries, while there exist only one bound state for the (4)He(20)NeH system in the 0(+) symmetry. We shall calculate the bound state energies and analyze the molecular structures of these species in detail.     

Synthesis of para- or ortho-substituted triarylbilindiones and tetraarylbiladienones by coupled oxidation of tetraarylporphyrins

Coupled oxidation of [tetraarylporphyrinato]iron(III) chloride carrying substituents in the ortho or para positions was performed by allowing the iron porphyrin to react with dioxygen, ascorbic acid, and pyridine to give biladienone as the major product and bilindione as a minor one. Efforts to find reaction conditions and workup procedures to obtain bilindione improved the yields of triarylbilindiones ranging between 2% and 19%. Electron-withdrawing substituents in the para position on the aryl groups increased the selectivity of bilindione relative to biladienone: the isolated yields of bilindione and biladienone were 2% and 85% (OMe), 6% and 44% (COOMe), and 7% and 28% (CN), respectively. Electronic effects of substituents affected both isolation procedures and the spectroscopic properties of bilindiones. Tri(4-methoxyphenyl)bilindione showed a red-shifted electronic absorption compared to unsubstituted and 4-methoxycarbonyl substituted analogues. This was ascribed to the destabilization of the HOMO-1 level by the methoxy groups.     

Use of dimethyl carbonate as a solvent greatly enhances the biaryl coupling of aryl iodides and organoboron reagents without adding any transition metal catalysts

The coupling reaction of aryl iodides with arylboronic acids to give biaryl compounds can be efficiently performed without adding a transition metal catalyst. The key to success is the use of dimethyl carbonate as a solvent. This finding provides a new strategy for constructing a biaryl linkage.     

The "off-on" fluorescence detection of alkaline earth metal ions by using 1-naphthylacetanilide derivatives: new cation sensors based on oligo-ethylene oxides connecting 1-naphthylacetanilide at its terminals.

New fluorescent ionophores containing the 1-naphthylacetanilide moiety based on oligo-ethylene oxide (1(4) and 1(5)) have been synthesized, and their photochemical behaviors have been studied. In the absence of a metal ion, the 1-naphthylacetanilide moiety showed a weak fluorescence emission (fluorescence "off state"). However, complexation with Ca(2+) induced a large enhancement effect on the fluorescence intensity of 1(4) and 1(5) from the naphthalene ring (fluorescence "on" state). This behavior can be explained in terms of a similar twisted intramolecular charge-transfer relaxation mechanism. Such "off-on" fluorescence responses of 1(4) and 1(5) provide the digital detection of alkaline earth metal ions.     

Cyclization reactions of homopropargyl azide derivatives catalyzed by PtCl4 in ethanol solution: synthesis of functionalized pyrrole derivatives

[Structure: see text] PtCl4-catalyzed cyclization reactions of homopropargyl azide derivatives to pyrrole rings were investigated. Using ethanol as solvent with 2,6-di-tert-butyl-4-methylpyridine as the base was found to be the best set of conditions for effecting this ring-closing reaction. These reaction conditions can be applied to the preparation of functionalized pyrrole derivatives, with no effect on the functional groups.     

Exciton recurrence motion in aggregate systems in the presence of quantized optical fields

The exciton dynamics of model aggregate systems, dimer, trimer, and pentamer, composed of two-state monomers is computationally investigated in the presence of three types of quantized optical fields, i.e., coherent, amplitude-squeezed, and phase-squeezed fields, in comparison with the case of classical laser fields. The constituent monomers are assumed to interact with each other by the dipole-dipole interaction, and the two-exciton model, which takes into account both the one- and two-exciton generations, is employed. As shown in previous studies, near-degenerate exciton states in the presence of a (near) resonant classical laser field create quantum superposition states and thus cause the spatial exciton recurrence motion after cutting the applied field. In contrast, continuously applied quantized optical fields turn out to induce similar exciton recurrence motions in the quiescent region between the collapse and revival behaviors of Rabi oscillation. The spatial features of exciton recurrence motions are shown to depend on the architecture of aggregates. It is also found that the coherent and amplitude-squeezed fields tend to induce longer-term exciton recurrence behavior than the phase-squeezed field. These features have a possibility for opening up a novel creation and control scheme of exciton recurrence motions in aggregate systems under the quantized optical fields.     

Compositeness Criteria of Particles in Quantum Field Theory and S-Matrix Theory

A review is given of recent developments in compositeness arguments of particles in the framework of Lagrangian field theory and S-matrix theory.     

BRDF color mapping using line scan camera

Optical Review - An optical imaging system for color mapping of the bidirectional reflectance distribution function (BRDF) using a line scan camera is proposed here that can detect slight BRDF...