Modulating the Lewis Acidity of Boron Using a Photoswitch


  • This work was supported by the Natural Sciences and Engineering Research Council of Canada, the Canada Research Chair Program, Simon Fraser University and the University of Zürich. K.K.B. would like to acknowledge the Swiss National Science Foundation for support of this work, and Donald Truhlar for enabling the use of the M06-2X functional recently developed but not yet in the public domain.


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Light turns the Lewis acid on: The Lewis acidity of a boron atom integrated into a cyclic dithienylethene photoswitch is modulated by light: 1 a has low Lewis acidity since the p orbital of the boron center is partially occupied by delocalized π electrons, whereas the rearrangement of the π electrons in 1 b reduces the electron density at the boron center and turns the Lewis acid “on”.