Reported herein is a photochemical cascade process that combines the excited-state and ground-state reactivity of chiral organocatalytic intermediates. This strategy directly converts racemic cyclopropanols and α,β-unsaturated aldehydes into stereochemically dense cyclopentanols with exquisite stereoselectivity. Mechanistic investigations have enabled elucidating the origin of the stereoconverg...

We demonstrate a photochemical reaction between graphene and benzoyl peroxide. This reaction introduces spatially localized defects into the graphene basal plane. The reactivity of the single-layer graphene is approximately 14 times higher than that of the double-layer graphene. Our result suggests that photoexcited graphene transfers a hot electron to benzoyl peroxide and induces its decomposi...

Quadratic electro-optic effects (QEOEs) and electro-absorption (EA) process in a GaN/AlGaN spherical quantum dot are theoretically investigated. It is found that the magnitude and resonant position of third-order nonlinear optical susceptibility depend on the nanostructure size and aluminum mole fraction. With increase of the well width and barrier potential, quadratic electro-optic effect and ...

In this work, the robust position control scheme is proposed for the electro-mechanical system using the disturbance observer and backstepping control method. To the external unknown load of the electro-mechanical system, the nonlinear disturbance observer is given to estimate the external unknown load. Combining the output of the developed nonlinear disturbance observer with backstepping techn...

Electro-oxidation reactions using a nickel anode were carried out on the calcium-spent liquor effluent obtained from Sappi Saiccor (formerly South African Industrial Cellulose Corporation) dissolving pulp mill as well as on ligninand lignan-type compounds previously identified in the effluent. Voltammograms were obtained for each solution in order to identify the oxidation potentials of the com...

This work is concerned with the diffraction and scattering of plane electro-acoustic waves by an interfacial crack between two dissimilar piezoelectric half-spaces. An exact solution is obtained for the full scattering field around the tip of the interfacial crack that is loaded with both acoustic SH and electric incident waves. First, it has been found that the interfacial crack is not complet...

Institute of Chemistry, Pedagogical University, Ch^ciriska 5, 25-020 Kielce, Poland Z. Naturforsch. 44b, 1589-1592 (1989); received March 29/July 21, 1989 Photochemical Reactions, Primary Aromatic Amines, Chloromethanes Major products of photochemical reactions of aniline in tetrachloromethane, chloroform and dichloromethane have been isolated and identified. The mechanisms of partial reactions...

Flavonoids and their photochemical transformations play an important role in biological processes in nature. Synthetic photochemistry allows access to molecules that cannot be obtained via more conventional methods. This review covers all published synthetic photochemical transformations of the different classes of flavonoids. It is first comprehensive review on the photochemistry of flavonoids.