N-Inversion in 2-azabicyclopentane derivatives: model simulations for a laser controlled molecular switch

Abstract

We report model quantum simulations for the nitrogen inversion in 2-azabicyclo[1.1.1]pentane derivates controlled by laser pulses proposing to use this class of molecules as molecular switches. The derivatives trans-5-fluoro-2-methyl-2-azabicyclo[1.1.1]pentane and cis-5-fluoro-2-methyl-2-azabicyclo[1.1.1]pentane are investigated by means of density functional theory and quantum wave packet dynamics. The molecules have two stable, i.e. energetically well-separated, conformers along the N-inversion coordinate. In 1D model simulations the transformation from one conformer to the other is accomplished in the electronic ground state by using two overlapping chirped linearly polarized IR laser pulses for the trans- and cis-isomer or alternatively via an electronic excited state employing a pump-dump sequence of ultrashort UV laser pulses.