Photo-thermal Transformation of Organoboranes
Suning Wang, Yingli Rao, Jiasheng Lu, Soo-Byung Ko, Sean
McDonald, Dengtao Yang, Soren Mellerup
Department of Chemistry
Queen’s University
Kingston, ON, K7L 3N7, Canada
Email: wangs@chem.queensu.ca
Organoboranes have recently emerged as an important class of photo-responsive materials with
versatile applications in optoelectronic,[1] sensory [2] and photochromic devices [3]. New and
unusual photo/thermal chemical and structural transformation that can be exploited for the
construction of new organoborane-based functional materials have gained much recent research
attention. [4] One of our key research interests is to examine and discover new reactivity and
structural transformation of organoboranes imparted by external stimuli such as light and heat. One
class of organoboranes that was found to be particularly interesting in terms of photoreactivity is
four-coordinate boron compounds with an N,C-chelate backbone and a B,N-cyclopentadienyl core.
This class of compounds transform to azabora-bisnorcaradienes upon irradiation by light with a
distinct color change. [3] In most instances, this transformation is fully reversible by heat.
Interestingly, however, depending on the nature of the N,C-chelate backbone, instead of thermal
reversal, some of the azabora-bisnorcaradienes can follow alternative reaction pathways upon
heating or irradiation by light, leading to further structural transformation.[5] The tenacity of this
class of organoboranes to remain intact by continuously transforming themselves upon heating or
irradiation is quite remarkable. In a related new class of organoborane compounds that contain a
B,N-cyclohexadienyl core and an N,C-chelate backbone, it was observed that instead of
photoisomerization, photoelimination occurs upon irradiation by light, leading to highly emissive
azaborine compounds [6]. This presentation will focus on our recent findings on the unusual photothermal isomerization and photoelimination phenomena of organoboranes.
Photo-thermal Isomerization
Photo-thermal Elimination
Bibliography
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