Synthesis and luminescence of a charge-neutral, cyclometalated iridium(III) complex containing N--C--N- and C--N--C-coordinating terdentate ligands.

摘要: The first examples of iridium(III) complexes containing a terdentate, N∧C∧N-coordinated 1,3-di(2-pyridyl)benzene derivative, cyclometalated at C2 the benzene ring, are reported. This mode binding becomes significant only if competitive cyclometalation C4/C6 is blocked, and ligand 1,3-di(2-pyridyl)-4,6-dimethylbenzene (dpyxH) has been prepared to achieve this condition. charge-neutral complex [Ir(dpyx)(dppy)], 2, (dppyH2 = 2,6-diphenylpyridine) isolated, dpyx dppy bound metal through one two carbon atoms, respectively. A terpyridyl analogue, [Ir(dpyx)(ttpy)](PF6)2, 3, (ttpy 4‘-tolylterpyridine) also its X-ray crystal structure determined, confirming N∧C∧N dpyx. Complex 2 emits strongly in degassed solution 295 K (λmax 585 nm, φ 0.21, τ 3900 ns, CH3CN). In solution, excited state can undergo photodissociation, cleavage Ir−C(dppy) bonds.