Switching the Photochromic Activity of Acenaphthylene Derivatives through a Tandem Nucleophile‐Promoted Addition Reaction

Abstract

New acenaphthylene-based dithienylethenes have been prepared. Surprisingly they did not show photochromism. However, they readily underwent a tandem addition of a nucleophile and an electrophile, leading to a small library of dearomatized colourless analogues, which, on the contrary, were endowed with photochromic activity. In the absence of the electrophile, the intermediate obtained by C-attack readily aromatizes to give, surprisingly, a final product of direct aromatic nucleophilic substitution, which was not photochromically active.

A Thorough Study on the Photoisomerization of Ferulic Acid Derivatives

“…The photon flux was determined using a chemical actinometer (see S.I.) [33] . The high concentration employed ensures a complete absorption of the incident photon by the sample at 350 nm (A>2) and therefore q (n,p) ≈q (n,p)absorbed .…”