Phosphorescent Pt II Systems Featuring Both 2,2′‐Dipyridylamine and 1,3,5‐Triazapentadiene Ligands

Abstract The treatment of cis ‐[Pt(dpa)(RCN) 2 ][SO 3 CF 3 ] 2 {dpa = 2,2′‐dipyridylamine, R = Me, Et, CH 2 Ph, Ph; [ 2a – d ](OTf) 2 } (OTf = SO 3 CF 3 ) with 2 equiv. of N , N′ ‐diphenylguanidine [NH=C(NHPh) 2 ] in CH 2 Cl 2 solutions at room temp. for 16 h gives [Pt(dpa){NH=C(R)NC(NHPh)=NPh}][SO 3 CF 3 ] {[ 3a , b , d ](OTf)} as the addition products and [Pt(dpa){NH=C(R)NHC(R)=NH}][SO 3 CF 3 ] 2 {[ 4a , b ](OTf) 2 } as the tailoring products. The formulation of complexes [ 3a , b , d ](OTf) and [ 4a , b ](OTf) 2 was supported by satisfactory C, H, and N elemental analyses and agreeable high‐resolution ESI‐MS, IR, and 1 H (including 1 H– 1 H COSY experiments) and 13 C{ 1 H} NMR data. The structures of all of the platinum species were determined by single‐crystal X‐ray diffraction. The resultant complexes are nonemissive in solution, mainly because of the interaction between the empty d   z   2orbital in a square‐planar configuration and solvent molecules. However, in the solid state, complexes [ 3a , b , d ](OTf) exhibit strong phosphorescence with quantum yields (peak wavelength) of 0.23 (490 nm), 0.27 (483 nm), and 0.20 (532 nm), respectively.