Introduction of a triphenylamine substituent on pyridyl rings as a springboard for a new appealing brightly luminescent 1,3-di-(2-pyridyl)benzene platinum(II) complex family

The preparation and characterization of three new complexes, namely [Pt(1,3-bis(4-triphenylamine-pyridin-2-yl)-4,6-difluoro-benzene)Cl] ([(PtLCl)-Cl-1]), [Pt(1,3-bis(4-triphenylamine-pyridin-2-yl)-5-triphenylamine-benzene)Cl] ([(PtLCl)-Cl-2]), and [Pt(1,3-bis(4-triphenylamine-pyridin-2-yl)-5-mesityl-benzene)Cl] ([(PtLCl)-Cl-3]), is reported. All of them are highly luminescent in dilute deaerated dichloromethane solution (phi(lum) = 0.88-0.90, in the yellow-green region; the lambda(max,em) in nm for the monomers are: 562, 561 and 549 for [(PtLCl)-Cl-1], [(PtLCl)-Cl-2] and [(PtLCl)-Cl-3], respectively).[(PtLCl)-Cl-1] is the most appealing, being characterized by a very long lifetime (103.9 mu s) and displaying intense NIR emission in concentrated deaerated solution (phi(lum) = 0.66) with essentially no "contamination" by visible light < 600 nm. This complex allows the fabrication of both yellow-green and deep red/NIR OLEDs; OLED emissions are in the yellow-green (CIE = 0.38, 0.56) and deep red/NIR (CIE = 0.65, 0,34) regions, for [(PtLCl)-Cl-1] 8 wt% (with 11% ph/e EQE) and pure [(PtLCl)-Cl-1] (with 4.3% ph/e EQE), respectively.