Unsymmetrically Functionalized 5,5″-diaryl-and 5,6,5″-triaryl-2,2′:6′,2″-terpyridines: An Efficient Synthetic Route and Photophysical Properties

Abstract

An efficient approach for the synthesis of 5,5″-or 5,6,5″-aryl substituted 2,2′:6′,2″-terpyridines, bearing an anneleted cyclopentene unit in one of the side-chain pyridine rings for the improved solubility in organic solvents, via their 1,2,4-triazine analogues has been developed. By using this approach, various aromatic substituents were introduced in the 2,2′:6′,2″-terpyridine core. Depending on the nature of the aromatic substituents, the obtained terpyridines exhibited an intense emission in a range of ca. 344-394 nm in acetonitrile solutions. For the most representative compounds, pronounced bathochromic shifts in both absorption and emission spectra were observed compared with previously reported substituted terpyridines. © 2017 Published by NRC Research Press.