46. Yu Wang, Kanglei Liu, Pangkuan Chen, Xiaodong Yin, Tai Peng,* Javed Iqbal and Nan Wang *, A multi-responsive system based on intramolecular B<-O=P Lewis acid–base pairs, J. Mater. Chem. C, 2022, 10, 10981



A series of amino-triarylborane based flexible Lewis pairs with P(O)R2 (R = phenyl, methylphenyl) and
BR2 (R = 2,4,6-trimethylphenyl (Mes), 2,6-dimethyl-4-methoxyphenyl (Mes(OMe)) were synthesized and
fully characterized. These compounds display distinct responses toward multiple external stimuli
including solvent, temperature and pressure. A detailed study shows that the ability of reversible
switching between the open and closed structures based on the intramolecular B ’ O bond plays a key
role in their solution state fluorescence response to external stimuli, which can be further tuned by adjusting
the electronic/steric properties of the substituents on the BR2/P(O)R2 unit. All these compounds exhibit
remarkable mechanochromism. Furthermore, upon grinding, pressure-induced blue-shifted and red-shifted
emissions were observed for B2/B3 and B1/B4, respectively. This solid state emission change is fully
reversible for B2–B4 upon exposure to vapours of several common solvents.