Properties and structure of two fluorinated 1,10-phenanthrolines

Abstract

Abstract We report the synthesis, X-ray structure, absorbance and emission of 4,7-bis(4-fluorophenyl)-1,10-phenanthroline and 4,7-bis-(4′-trifluoromethyl-biphenyl-4-yl)-1,10-phenanthroline. 4,7-Bis(4-fluorophenyl)-1,10-phenanthroline was synthesized by successive Skraup reactions and features absorbance at 274 nm and emission at 384 nm while 4,7-bis-(4′-trifluoromethyl-biphenyl-4-yl)-1,10-phenanthroline featured absorbance at 283 nm and emission at 400 nm. The structures show molecular stacking of the phenyl groups and phenanthroline structure and longitudinal fluorine atom associations within the crystal lattice. Furthermore, the three fused rings of the 4,7-bis(4-fluorophenyl)-1,10-phenanthroline unit exhibited torsion up to 13.97(9)° throughout the crystal lattice whereas no torsion is observed for 4,7-bis-(4′-trifluoromethyl-biphenyl-4-yl)-1,10-phenanthroline.