Effectively red-emitting platinum(II) complexes with sterically bulky phenyltriazoles ligands

Novel luminescent dinuclear and mononuclear cycloplatinated(II) complexes (1-3 and 4-6) with OPPh3- and PPh3-functionalized 2-phenyl-triazole ligands (L1-L3 and L4-L6) are synthesized and structural characterized. The coordination of the individual Pt(II) centers in dinuclear and mononuclear complexes are [Pt(N-N)(C<^>N)] and [Pt(P<^>N)(C<^>N)], where N-N, C<^>N and P<^>N mean a bridging coordination, a five-membered ring and a sixmembered ring, respectively. Bulky 2-phenyltriazole ligands L1-L6 can reduce intermolecular pi-pi and Pt-Pt interactions and increase rigidity of complexes, therefore these complexes show superior monomeric emissions with the quantum yields of 14.5 %-25.7 % in dichloromethane at 298K. The luminescence mainly originates from mixed 3LC/3MLCT states.