A Theoretical Perspective on the Photochemistry of Boron–Nitrogen Lewis Adducts

Boron–Nitrogen
(B–N) Lewis adducts form a versatile
family of compounds with numerous applications in functional molecules.
Despite the growing interest in this family of compounds for optoelectronic
applications, little is currently known about their photophysics and
photochemistry. Even the electronic absorption spectrum of ammonia
borane, the textbook example of a B–N Lewis adduct, is unavailable.
Given the versatility of the light-induced processes exhibited by
these molecules, we propose in this work a detailed theoretical study
of the photochemistry and photophysics of simple B–N Lewis
adducts. We used advanced techniques in computational photochemistry
to identify and characterize the possible photochemical pathways followed
by ammonia borane and extended this knowledge to the substituted B–N
Lewis adducts pyridine-borane and pyridine-boric acid. The photochemistry
observed for this series of molecules allows us to extract qualitative
rules to rationalize the light-induced behavior of more complex B–N-containing
molecules.