A New Class of Neutral Boron‐Based Diradicals Spanned by a Two‐Carbon‐Atom Bridge.

A new structural class of boron‐based diradicals is prepared by Lewis base addition to and reduction of singly cyclic (alkyl)(amino)carbene (CAAC) stabilised diborylalkenes. The diradicals feature a perpendicular olefinic bridge preventing delocalization between the B(CAAC) π systems, making the coupling between the spin centres very weak. DFT calculations indicate that the compounds are ground‐state (open‐shell) singlets, with triplet states negligibly higher in energy, thus making the triplet states easily populated thermally. B(CAAC) for more: A new structural class of boron‐based diradicals is prepared by Lewis base addition to and reduction of singly CAAC‐stabilised diborylalkenes. The diradicals feature a perpendicular olefinic bridge preventing delocalization between the B(CAAC) π systems, making the coupling between the spin centres very weak. [ABSTRACT FROM AUTHOR]