Photoisomerization of Arylazopyrazole Photoswitches: Stereospecific Excited-State Relaxation.

ABSTRACT: Electronic structure calculations and nonadiabatic dynamics simulations (more than 2000 trajectories) are used to explore the Z-E photoisomerization mechanism and excited-state decay dynamics of two arylazopyrazole photoswitches. Two chiral S₁ /S₀ conical intersections with associated enantiomeric S₁ relaxation paths that are barrierless and efficient (timescale of ca. 50 fs) were found. For the parent arylazopyrazole (Z8) both paths contribute evenly to the S₁ excited-state decay, whereas for the dimethyl derivative (Z11) each of the two chiral cis minima decays almost exclusively through one specific enantiomeric S₁ relaxation path. To our knowledge, the Z11 arylazopyrazole is thus the first example for nearly stereospecific unidirec

SUBMITTER: Wang YT 

PROVIDER: S-EPMC5113807 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature