A Comparative Study of the Electronic Property of a Series of 2,4,6-Tri(5-Aryl-2-Thienyl)-1,3,5-Triazines Controlled by the Electronic Nature of Aryl Groups

GRAPHICAL ABSTRACT

Abstract

A series of 2,4,6-tri(5-aryl-2-thienyl)-1,3,5-triazines with a star-shaped π-conjugated system as a wide variety of aryl-functionalized 2,4,6-tri(2-thienyl)-1,3,5-triazines were designed and systematically synthesized. The electronic properties of these compounds in the solution state were identified by ultraviolet-visible infrared absorption and emission spectroscopies, and cyclic voltammetric studies. The results of the experimental observations demonstrated that the changing electronic nature of terminal aryl groups helps to efficiently tune the optical and redox properties of the 2,4,6-tri(5-aryl-2-thienyl)-1,3,5-triazines. Interestingly, 5-(p-N,N-dibutylaminophenyl-2-thienyl)-1,3,5-triazine exhibits solvatochromic properties and a proton-sensibility due to its intramolecular charge transfer and basic characters, which can be confirmed visually from changes in the color of the solution and emission.

Keywords:

• 1,3,5-triazine
• thiophene
• intramolecular charge transfer
• solvatochromism
• proton-sensing