9 research outputs found
Electron density stratification in two-dimensional structures tuned by electric field
A new kinetic instability which results in formation of charge density waves
is proposed. The instability is of a purely classical nature. A spatial period
of arising space-charge and field configuration is inversely proportional to
electric field and can be tuned by applied voltage. The instability has no
interpretation in the framework of traditional hydrodynamic approach, since it
arises from modulation of an electron distribution function both in coordinate
and energy spaces. The phenomenon can be observed in thin 2D nanostructures at
relatively low electron density.Comment: 4 pages, 2 figure
From Cationic to Anionic Helicenes: New Reactivity through Umpolung
Using a two-step reduction/metalation procedure, highly stable chiral carbenium ions are transformed into reactive carbanion intermediates. Interesting polar ketone and thioamide products are the results of this umpolung that occurs with complete retention of configuration of the helical backbone