Umpolung of reactivity of allylsilane,allylgermane, and allylstannane via their reaction with thallium (III) salt: a new allylation reaction for aromatic compound

A new direct allylation of the aromatic compound has been developed. A combination of allylsilane, allylgermane, or allylstannane and thallium (III) trifluoroacetate gave rise to an allyl cationic species which was allowed to react with an aromatic compound, a nucleophile, to give allylation product(s) in good yields.     

Reaction of allylsilane with α-nitro olefin and its development to synthesis of cyclopentenone

Michael addition of allylsilane to α-nitro olefin in the presence of AlCl₃ proceeded smoothly at low temperature to give unsaturated nitronic acid, which was converted into the γδ-enone using aqueous Ti (III). Transformation with the latter provided a convenient new synthesis of cyclopentenone.     

Notes on the Asymptotic Linearity Theorems

The present article provides three lemmas that initiate the generalization of the theory of additive correlation involving the Asymptotic Linearity Theorems, which were constructed for a study of the correlation between structure and properties in molecules having many identical moieties. The new tools provided here also help to pave the way to linking the above theory with a theoretical framework developed for the asymptotic analysis of certain chemical kinetic network systems.On leave from: Institute for Fundamental Chemistry, 34-4 Takano-Nishihiraki-cho, Sakyo-ku, Kyoto 606, Japan.     

Unexpected reduction of the spin-exchange cross-section for fast 3He+ ions incident on Rb atoms

The spin-exchange cross-section, , was measured for a 6.33 keV/amu He ion incident on a polarized Rb atom. The result is cm², which is unexpectedly an order of magnitude smaller than the theoretical value cm² evaluated by the semiclassical impact parameter method assuming formation of a single molecular state. Received 11 September 1999 and Received in final form 28 December 1999     

Magic Mountain and Devil's Staircase swapping problems

Two open questions concerning additivity problems in theoretical chemistry have been posed in this article. Each question involves swapping of the square root function (in the formula for the zero-point energy of a linear oscillator) with a highly irregular function. Global contextualization of molecular problems and function swapping are indispensable strategies in tackling additivity problems in theoretical chemistry.     

Correlation between electronic states and optical properties in indirect GaAsP/GaP quantum wells with insertion of an ultrathin AlP layer

The optical properties of indirect semiconductor quantum wells (QWs), were studied in relation to their electronic states controlled by an ultrathin AlP layer. The insertion of 1 ML of AlP at the center of a 60 Å GaAsP/GaP QW drastically increased the photoluminescence (PL) intensity and the efficiency of the no-phonon (NP) transition. The NP intensity relative to its TO phonon replica was found to greatly depend on the structural parameters and decreased by decreasing the width of the AlP layer or by increasing the arsenic composition of the GaAsP QW. The comparison with numerical calculation clarified that the efficiency of the NP transition is improved when the X_z electrons rather than X_xy electrons are involved in the radiative recombination. This can be qualitatively understood that the X_z electrons are more strongly localized to the AlP layer, leading to the efficient relaxation of the selection rule. The Arrhenius behavior of the PL intensity was also studied and the quenching of the PL intensity was interpreted as being due to the thermally activated escape of carriers from the well region into the GaP barrier.     

Proof of the Fukui conjecture via resolution of singularities and related methods. IV

The present article is a direct continuation of the previous part III of this series of articles, which have been devoted to cultivating a new interdisciplinary region between chemistry and mathematics. In the present part IV, we develop two sets of fundamental theoretical tools, using methods from the field of resolution of singularities and analytic curves. These two sets of tools are essential in structurally elucidating the assertion of the Fukui conjecture (concerning the additivity problems) and the crux of the functional asymptotic linearity theorem (functional ALT) that proves the conjecture in a broad context. This conjecture is a vital guideline for a future development of the repeat theory (RST)—the central unifying theory in the First and the Second Generation Fukui Project.     

Coherent Array of White-Light Continuum Generated by Microlens Array

We generated a white-light continuum array by directing femtosecond laser pulses into a liquid with a microlens array. Experimental evidence demonstrates that the spatial coherence is high within a single light source in the array. We also confirmed that all the light sources in the white-light continuum array are mutually coherent. We found that the simple self-phase modulation model cannot explain this high coherence between the white continuum sources.     

Photoinduced magnetization in a two-dimensional cobalt octacyanotungstate

A new type of cyano-bridged Co-W bimetallic assembly, CsI[{CoII(3-cyanopyridine)2}{WV(CN)8}].H2O was synthesized. This compound exhibited a temperature-induced phase transition and a photoinduced magnetization. Irradiating with light induced a spontaneous magnetization with a magnetic phase transition temperature at 30 K. This photoinduced magnetization is due to the phase transition from CoIII(LS; S = 0)-WIV(S = 0) to CoII(HS; S = 3/2)-WV(S = 1/2) phases by the irradiation.     

Polyhedral shapes of functional group distributions in biomolecules and related similarity measures

The distribution of the essential functional groups within biomolecules is described by a series of polyhedral models. As a function of a threshold of the electronic density of the biomolecule, the combinatorial types of these polyhedra are threshold-dependent within each series, resulting in a characteristic sequence of combinatorial types for each biomolecule. A comparison of combinatorial types is the basis for the introduction of new measures of shape similarity and shape complementarity between biomolecules. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 66 : 99–105, 1998