Influence of ancillary ligands on the photophysical properties of cyclometalated organoplatinum(ii) complexes

Abstract

Three series of cyclometalated organoplatinum(II) complexes [Pt(p-MeC₆H₄)(bhq)(L)], in which bhq is benzo[h]quinolinate and L is PPh₃ (1a), PPh₂Me (1b), or PPhMe₂ (1c); [Pt(p-XC₆H₄)(bhq)(PPh₂Me)], in which X is H (2a), F (2b), ^tBu (2c), OMe (2d), or Me (2e = 1b); and [Pt(bhq)X(PPh₂Me)], in which X is CF₃CO₂ (3a), Cl (3b), or I (3c) were synthesized and fully characterized using multinuclear (¹H and ³¹P) NMR spectroscopy and elemental analysis. Typical complexes [Pt(p-MeC₆H₄)(bhq)(PPhMe₂)], 1c, [Pt(p-MeC₆H₄)(bhq)(PPh₂Me)], 2e, and [Pt(bhq)Cl(PPh₂Me)], 3b, were further characterized by single crystal X-ray crystallography. The photophysical properties of all the complexes were studied and the influence of changing the ancillary ligands and substituents on their luminescence properties were investigated and the assignments were confirmed by TD–DFT calculations.