Synthesis and Optical Properties of C,N-Swapped Boranils Derived from Potassium Acyltrifluoroborates

Novel C,O-chelated bora-heterocycles were synthesized. Reaction of potassium acyltrifluoroborates with tetrahydroquinolin-8-ol furnished C,N-swapped boranils in a single step. All five obtained borates showed photoluminescence in solid state. One of them showed yellow-to-orange reversible mechano-chromic luminescence. Further derivatization afforded a B-chiral borate with an O,C, O-tridentate ligand that showed significant thermochromism