A curve-crossing model to rationalize and optimize diarylethene dyads

Area of Science:

• Photochemistry
• Theoretical Chemistry
• Materials Science

Background:

• Developing multi-addressable photochromic multimers is difficult, often leading to reduced photoactivity due to interactions between photochromic units.
• The complexity of coupled photochromes presents significant challenges for theoretical chemistry and computational modeling.

Purpose of the Study:

• To understand the fundamental difficulties in creating efficient multiphotochromic compounds.
• To develop a theoretical model and screening criterion for designing novel multi-addressable photochromic materials.

Main Methods:

• An effective curve-crossing model was developed and utilized.
• Ab initio data was employed in conjunction with the curve-crossing model.
• A novel tilt criterion was defined for screening potential multi-photochrome designs.

Main Results:

• The study elucidates the necessity of specific extra crossing points for multiphotochrome reactivity.
• A new, intuitive tilt criterion was established to aid in the design of multi-addressable photochromic compounds.
• The compatibility of the tilt criterion with existing static Franck-Condon parameters was assessed.

Conclusions:

• The developed curve-crossing model provides insights into the challenges of multiphotochrome design.
• The intuitive tilt criterion offers a practical tool for accelerating the discovery of new photochromic materials.
• This work facilitates the rational design of advanced photochromic systems with enhanced functionality.