Inorganic Chemistry, Vol.49, No.20, 9169-9177, 2010
Highly Fluorescent Platinum(II) Organometallic Complexes of Perylene and Perylene Monoimide, with Pt sigma-Bonded Directly to the Perylene Core
3-Bromoperylene (BrPer) or N-(2,5-di-tert-butylphenyl)-9-bromo-perylene-3,4-dicarboximide (BrPMI) react with [Pt(PEt3)(4)] to yield trans-[PtR(PEt3)(2)Br] (R = Per, la; R = PMI, lb). Neutral and cationic perylenyl complexes containing a Pt(PEt3)X group have been prepared from la,b by substitution of the Br ligand by a variety of other ligands (NCS, ON, NO3, (CNBu)-Bu-t, PyMe). The X-ray structures of trans-[PtR(PEt3)(2)X] (R = Per, X = NCS (2a); R = PMI, X = NO3 (4b); R = Per, X = (CNBu)-Bu-t (5a)) show that the perylenyl fragment remains nearly planar and is arranged almost orthogonal to the coordination plane: The three molecules appear as individual entities in the solid state, with no pi-pi stacking of perylenyl rings. Each platinum complex exhibits fluorescence associated to the perylene or PMI fragments with emission quantum yields, in solution at room temperature, in the range 0.30-0.80 and emission lifetimes similar to 4 ns, but with significantly different emission maxima, by influence of the X ligands on Pt. The similarity of the overall luminescence spectra of these metalated complexes with the perylene or PMI strongly suggests a perylene-dominated intraligand pi-pi(star) emissive state, metal-perturbed by interaction of the platinum fragment mostly via polarization of the Ar-Pt bond.