Abstract A series of unsymmetrical difluoro-boron (BF 2) complexes with pyridine and imidazoline were synthesized by reaction of new chelating ligands (arylmethyl- imidazolidinylidene)-pyridin-2-yl-amine with boron trifluoride diethyl etherate. All the ligands and BF 2 complexes were structurally characterized by IR, HRMS, 1 H, 13 C, 11 B, and 19 F NMR, indicating the bidentate complexation of imidazoline nitrogen and the pyridine ...