Cyclometalated Platinum(II) Complexes with 10-(Aryl)phenoxarsine Ligands: Synthesis, Structure, and Photophysical Properties

A series of C^N-cyclometalated platinum(II) complexes [Pt(ppy)X(L)] (ppy = 2-phenylpyridinate, X = Cl and I) with 10-(aryl)phenoxarsines, namely 10-(p-tolyl)phenoxarsine (L1), 10-(p-fluorophenyl)phenoxarsine (L2), 10-(m-fluorophenyl)phenoxarsine (L3), and 10-(phenyl)phenoxarsine (L4), was synthesized. The structure of the complexes was determined by in-dept NMR spectroscopy, mass spectrometry, and X-ray analysis. The UV/vis absorption and emission properties were studied and rationalized by DFT and time-dependent DFT calculations. In the solid state, under UV irradiation, platinum complexes with chloro ligands exhibit an intense green emission, which was attributed to a 3IL/3(X,M)LCT triplet state.