Synthesis and Electronic Spectroscopy of Luminescent Cyclometalated Platinum−Anthracenyl Complexes

Dicyclometalated complexes syn- and anti-[Pt2(L)2(PAnP-H2)](OTf)2 (Pt2) are synthesized from reactions of 9,10-bis(diphenylphosphino)anthracene (PAnP) and Pt(L)(OTf)2 (L = diphosphines, OTf = CF3SO3). Because of metal perturbation on the electronic structure of the anthracenyl ring, the 1B2u− ← 1Ag transition, which is forbidden in anthracene, is observed in the electronic spectra of Pt2. The complexes display fluorescence arising from the ligand-centered S1 excited state. No significant heavy atom effect is observed in the Pt2 complexes. To understand the effect of the number of Pt ions on the extent of perturbation, a mononuclear analogue, [Pt(dppe)(PAn-H)]ClO4 (PAn = 9-diphenylphosphinoanthracene), is prepared and its spectroscopy studied.