Fast switching immobilized photochromic dyes

A novel photochromic dye conjugate architecture is described, which allows both covalent tethering to a polymeric host matrix and fast photochromic switching. The new conjugates consist of a photochromic dye covalently bound to two different substituents via a Y-branching linker (hetero Y-branching), one being a polymerizable methacrylate moiety and the other a soft (low T-g) poly(dimethylsiloxane) oligomer. The novel conjugates gave faster photochromic decoloration in the host lens matrix compared with the electronically equivalent nonmatrix-bound and unconjugated parent control dyes. In addition, further acceleration of fade speed kinetics was observed with a longer linker between photochromic dye and methacrylate moiety. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 476-486, 2011