Synthesis and photophysics of platinum(II) complexes bearing 2-(7-(4-R-phenylethynyl)-9,9-dihexadecyl-fluoren-2-yl)-1,10-phenanthroline ligand

A series of platinum(II) complexes bearing 2-(7-(4-R-phenylethynyl)-9,9-dihexadecyl-fluoren-2-yl)-1,10-phenanthroline ligand were synthesized and characterized. Their photophysical properties were systematically investigated by UV–Vis absorption, emission, and transient absorption spectroscopy. All complexes exhibit 1π,π∗ absorption bands below 410 nm and charge transfer transitions at 415–550 nm in CH2Cl2. They all emit at ca. 624 nm with vibronic structures. Both UV–Vis absorption and emission spectra show negative solvatochromic effect. All complexes exhibit broad and moderately strong triplet transient absorption from the near-UV to the near-IR spectral region. Reverse saturable absorption of these complexes in CH2Cl2 for ns laser pulses at 532 nm was demonstrated.