A Comparative Study on Phosphorescent Cycloplatinated Complexes Based on Tridentate (CNN)-N-boolean AND-N-boolean AND-Coordinating Ligands and Phenylethynyl or Phenyl Ligand

作者：Mroz Robert; Vezzu Dileep A K; Wallace Brain; Ravindranathan Deepak; Carroll Jeffrey; Pike Robert D; Huo Shouquan^*

来源：Chinese Journal of Organic Chemistry, 2018, 38(1): 171-182.

DOI：10.6023/cjoc201709010

• platinum complexes
• phosphorescent materials
• crystal structure
• photophysics

Two series of platinum complexes, 1a similar to 6a and 1b-6b, based on tridentate cyclometalating ligands 2-Aryl-6-(1H-pyrazol-1-yl) pyridine [Ar=phenyl (L1), 2,4-difluorophenyl (L2), 3,5-dimethylphenyl (L3), 3-methoxyphenyl (L4), 2-thienyl (L5), 2-benzothienyl (L6)], and phenylethynyl and phenyl ancillary ligand were synthesized and characterized. The X-ray crystal structures of 2b, 3b and 5b were determined, which revealed a twisted orientation of the phenyl ligand with respect to the coordination plane and a weaker Pt-C(phenyl) bond compared with the Pt-C(alkynyl) bond in 1a. Photophysical properties including electronic absorption and emission spectra were studied. Complexes 1a similar to 6a based on the phenylethynyl ligand were strongly emissive, while 1b similar to 3b based on the phenyl ligand were only weakly emissive. However, 4b similar to 6b displayed lower but decent photoluminescent quantum yields than those of 4a similar to 6a, which is explained by the localization of the excited states in the tridentate cyclometalating ligands. The higher quantum efficiencies displayed by the complexes 1a similar to 6a may be attributed to the stronger and more rigid acetylide ligand.

• 出版日期2018-1-25
• 单位East Carolina