Construction of metallo-complexes with 2,2′:6′,2″-terpyridine substituted triphenylamine in different modified positions and their photophysical properties

The stable coordinated metallo-complexes based on 2,2′:6′,2″-terpyridine (tpy) and its derivatives have been widely researched for various wide-ranging applications in photoelectronics, catalysis, sensor, photoluminescence, and so on. However, the most reported studies ignored the comprehensive comparison between structures modified by different positions and photoluminescence. Herein, we design a series of metallo-complexes which were assembled with tpy substituted triphenylamine (TPA) at different positions and metal ions and explored their photophysical properties. In the solution state, MLE2 based on the 5,5″-positions modification showed the highest PLQYs and PL intensity. With the increase of solvent polarity, MLB2 exhibit the largest redshift. In the solid state, from MLA2 to MLE2, the emission colours are gradually red-shifted from yellow to red. The findings in this work may pave a new way to design functional metallo-complexes, not just for PL properties.