Reaction of 4,5-difluoroacridine (8) with two equivalents of potassium diphenylphosphide (Ph 2 PK) yielded the title compound 3. Contrarily, diphenylphosphine (Ph 2 PH) reacted with 8 under addition, and 4,5-difluoro-9-diphenyl-9,10-dihydroacridine (12) was obtained. Compound 8 was prepared from 2-amino-3-fluorobenzoic acid (13) in a four step synthesis. As it is shown by the preparation of the metal complexes 4,5-bis(diphenylphosphino)-acridine-palladium dichloride (16) and 4,5-bis(diphenylphosphino)acridine-molybdenum tricarbonyl (17), compound 3 is capable of acting as a tridentate PNP ligand which coordinates transition metals in an approximately “T-shaped” planar coordination geometry. Single crystal X-ray structure analyses are reported for 3 and 17.