Highly Efficient Reversible Z-E Photoisomerization of a Bridged Azobenzene with Visible Light through Resolved S_1(nπ*) Absorption Bands

摘要

Photochromic molecules, which can be reversibly switched between two isomeric forms with different colors, structures, or functional properties by light at distinctive wavelengths, attract ubiquitous attention for applications as optical memory and logic devices, or as molecular motors, machines, or manipulators.1'2 Azobenzene (AB) and its derivatives enjoy particular interest because of the large-amplitude structural changes between their elongated (E) and more compact (Z) forms, the reversibility of their transformations, and the high photostabilities which guarantee large numbers of switching cycles.