Pt^II Complexes with 6‐(5‐Trifluoromethyl‐Pyrazol‐3‐yl)‐2,2′‐Bipyridine Terdentate Chelating Ligands: Synthesis, Characterization, and Luminescent Properties

Abstract

A series of Pt(II) complexes Pt(fpbpy)Cl (1), Pt(fpbpy)(OAc) (2), Pt(fpbpy)(NHCOMe) (3), Pt(fpbpy)(NHCOEt) (4), and [Pt(fpbpy)(NCMe)](BF(4)) (5) with deprotonated 6-(5-trifluoromethyl-pyrazol-3-yl)-2,2'-bipyridine terdentate ligand are prepared, among which 1 is converted to complexes 2-5 by a simple ligand substitution. Alternatively, acetamide complex 3 is prepared by hydrolysis of acetonitrile complex 5, while the back conversion from 3 to 1 is regulated by the addition of HCl solution, showing the reaction sequence 1-->5-->3-->1. Multilayer OLED devices are successfully fabricated by using triphenyl-(4-(9-phenyl-9H-fluoren-9-yl)phenyl) silane (TPSi-F) as host material and with doping concentrations of 1 varying from 7 to 100 %. The electroluminescence showed a substantial red-shifting versus the normal photoluminescence detected in solution. Moreover, at a doping concentration of 28 %, the device showed a saturated red luminescence with a maximum external quantum yield of 8.5 % at 20 mA cm(-2) and a peak luminescence of 47,543 cd m(-2) at 18.5 V.

Metal Complexes with Azolate‐Functionalized Multidentate Ligands: Tactical Designs and Optoelectronic Applications

“…The pz CF3 bpyH chelate is also capable of reacting with K 2 PtCl 4 to afford [Pt(pz CF3 bpy)Cl] ( 9 ) (cf. Scheme ) in mixture of acetonitrile and water . The electron‐withdrawing CF 3 substituent of pz CF3 bpy chelate effectively reduced the donor strength of the adjacent nitrogen atom.…”

“…[23] The electron-withdrawing CF 3 substituento fp z CF3 bpy chelate effectively reduced the donor strength of the adjacent nitrogen atom. Scheme 3) in mixture of acetonitrile and water.…”

“…Scheme 3) in mixture of acetonitrile and water. [23] The electron-withdrawing CF 3 substituento fp z CF3 bpy chelate effectively reduced the donor strength of the adjacent nitrogen atom. This result is in sharp contrastt ot he related bidentate ligands, 2-pyridylpyrazole, which are known to form the protonated Pt II complex [Pt(fppyH)Cl 2 ]i nt he presence of HCl (aq) (fppyH = 3-trifluoromethyl-5-pyrid-2-yl-1H-pyrazole).…”

Emissive Iridium(III) Complexes with Phosphorous‐Containing Ancillary

“…As for the emission, both 57 and 58 with terminal chloride exhibit inferior quantum yields (Φ=0.02 and 0.04), a result of the chloride π‐donation that stabilize the upper lying MC dd states and providing an accessible channel for nonradiative deactivation . In contrast, complex 59 with cyclometalate ancillary showed emission with onset at 457 nm, which is more blue‐shifted compared to that of FIrpic at 470 nm, and an increased PL Q.Y.…”

Synthesis and characterization of mono- and dinuclear copper(I) complexes with 3-(2-pyrimidinyl)-1,2,4-triazine

“…There has been much interest in the synthesis of metal complexes featuring multiple nitrogen heterocyclic ligands [1][2][3][4][5][6][7][8], particularly in terms of multicentered metal-based systems exhibiting electronic interactions [9,10]. Bidentate binding of bridging units is desirable owing to the enhanced complex stability of chelating ligands as well as enhanced inter-metal electronic interactions.…”