Pyrene-based red room-temperature phosphorescent guest-materials with high quantum yield and narrow emission peak.

Organic room-temperature phosphorescent (RTP) materials exhibiting red emission are well known for short lifetime, broad emission or low quantum yield. Here, donor and acceptor groups were introduced to the 1- and 6- positions of pyrene to construct high performance pyrene-based red phosphorescent guest materials. All the synthesized pyrene derivatives (Pr-Py, O-Pr-Py, N-Pr-Py and Pr-Py-N) display pure red phosphorescent emission (main peaks located at ∼636, ∼655, ∼660 and ∼ 682 nm, respectively), high phosphorescent quantum yield and narrow emission peak in BP doped system. Especially, Pr-Py-N/BP (Pr-Py-N/BP) has a high phosphorescent quantum yield about 9.00 % (8.72 %) with a remarkable lifetime about 60.15 (66.49) ms and a narrow emission peak FWHM = 50 (60). Experimental and theoretical results demonstrated that acceptor regulation made pyrene-pyrimidine to act as a chromophore different from pyrene. Donor regulation is helpful to BP to approach the donor group of pyrene derivatives, which ensures the main emission peak originating from lowest energy structure and finally get high quantum yield and narrow phosphorescent emission.