Amine adducts of (4-ClC6H4)3B3O3, Lewis acidity of triarylboroxines, and an XRD study on the related tetraphenylboroxinate(1-) salt, [C6H11NMe3][Ph4B3O3]

Tri(4-chlorophenyl)boroxine.morpholine (1a) is one of several N-donor adducts of tri(4-chlorophenyl)boroxine to be prepared. Ligand dissociation/recombination occurs for 1a in CDCl3 solution with ΔG‡ (VT 1H NMR) of ca. 52 kJ mol-1.119