Controlling the Isomerization Rate of an Azo-BF2 Switch Using Aggregation.

A novel visible-light activated azo-BF2 switch possessing a phenanthridinyl π-system has been synthesized, and its switching properties have been characterized as a function of concentration. The switch self-aggregates through π-π interactions, and the degree of aggregation modulates the Z → E thermal isomerization rate. This property allows for the active tuning of the thermal relaxation half-life of the same switch from seconds to days.