Syntheses, Structures, and Luminescent Properties of Dipyridylamine-Functionalized Anthracene and Its Complexes

A novel multidentate ligand with 2,2′-dipyridylamine
functionalities,
1,8-bis­[4-(2,2′-dipyridylamino)­phenylacetylenyl]­anthracene
(1), has been synthesized through a double Sonogashira
coupling reaction and characterized by NMR spectroscopic, elemental,
and X-ray diffraction analyses. Compound 1 can bind to
either one metal center as a tetradentate ligand or two metal centers
as a double-bidentate ligand. In the double-bidentate mode, the distance
between the two metal centers may vary significantly. Compound 1 displays bright blue luminescence in the solid state and
in solution with a quantum efficiency of 64% relative to 9,10-diphenylanthracene.
While the dirhodium complex of 1 shows no luminescence,
the two zinc complexes of 1 display blue luminescence
with quantum efficiencies slightly lower than that of 1. Organic light-emitting devices (OLEDs) using 1 as
the emitter show a maximum current efficiency of 7 cd/A.