Triplet Emitters of Clamshell Binuclear Pd(II) Complexes

Three clamshell binuclear Pd(II) complexes have been synthesized using the primary cyclometallating ligands of phenylpyridine (ppy) and its derivatives with the ancillary clamping ligand of 3,5‐di‐tert‐butyl‐1H‐pyrazole (dbp). All three complexes are fully characterized by nuclear magnetic resonance, high‐resolution mass spectrometry, cyclic voltammetry, and single‐crystal X‐ray diffraction, and the crystal structures exhibited the Pd–Pd distances between 2.813 to 2.882 Å. It is a pioneering report of a group of binuclear Pd(II) complexes showing intensive triplet emission between 635 to 764 nm with the nature of metal‐metal‐to‐ligand charge transfer at room temperature.