Deep red PhOLED from dimeric salophen Platinum(II) complexes

The condensation of 3,3'-diaminobenzidine with different substituted salicylaldehyde afforded three dimeric salophen ligands H4L1-H4L3. Subsequently, their corresponding dimeric salophen platinum(II) complexes Pt2L1-Pt2L3 were prepared through the metallation of ligands with K2PtCl4. The ligands and complexes were characterized by H-1 NMR, infrared spectroscopy, mass spectrometry and elemental analysis and their thermal stabilities, photophysical properties, and electrochemical behavior were further investigated in detail. Using Pt2L1 as phosphorescent emitting materials, deep red light-emitting devices were fabricated with moderate efficiency. The maximum current efficiency, power efficiency, and brightness for the 3.0 wt % Pt2L1 doped OLED are 1.39 cd A-1, 0.74 lm.W-1 and 1774 cd m(-2), respectively. Given the synthetic simplicity and ease of structural variation, the preliminary results here indicate that these dimeric salophen complexes are good candidates for phosphorescent OLED.