move: The title compounds 1, which are unique heterocyclic systemscontaining a PB bond, have been synthesized by the reduction of 1‐diarylboryl‐8‐dichlorophosphinonaphthalene derivatives (see scheme). Bothexperimental and theoretical results for 1 revealed an effective interaction between the phosphorus atom, boron atom, and naphthyl moiety. Furthermore, 1 exhibits orange fluorescence in solution