High specific enthalpies from the photochemically induced isomerization: BOH↔HBO

The photochemical interconversion of BOH to the considerably more stable HBO isomer is evaluated. The BOH and HBO isomers, while differing considerably in energy, possess a significant barrier to interconversion on the ground 1A′ potential energy surface. However, by accessing the low-lying double minimum a 3A′ state, we define an interconversion pathway that facilitates the interconversion process, allowing a substantial energy release. Here, we calculate the potential surfaces for the X 1A′ and a 3A′ states of HBO–BOH and present limited evaluations for the b 3A″ and A 1A′ states. We outline means to distinguish the BOH and HBO isomers, following the progress of the isomerization process using optical, infrared, and mass spectrometric techniques. The energetics of this geometric isomerization process and the potential utilization of BOH as a storable high energy material are discussed.