Linear π-conjugated polymers containing 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine unit:: Synthesis and optical properties

Some linear pi-conjugated polymers containing 2,4,6-tris(thiophen-2-yl)1,3,5-triazine unit were synthesized via Sonogashira or Suzuki reaction for the first time and characterized by IR, NMR, and GPC. Because of the introduction of 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine unit into pi-conjugated system, all polymers exhibited good thermal stability with high decomposition temperature. Their optical and electrochemical properties were investigated. Based on the 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine unit linked with different aromatic rings, the polymers showed the tunable fluorescence from blue to blue-green emission with satisfied quantum yield. Cyclic voltammetry measurement indicated that the LUMO and HOMO levels of the polymers could be adjustable through the main-chain structural modification. All polymers had low LUMO level (-2.86 to -3.06 eV) due to the high-electron affinity of triazine unit. (c) 2007 Wiley Periodicals, Inc.