In this study, oligo(3-methylthiothiophene) was synthesized from thiophene derivative according to the method of reductive coupling using palladium catalyst. For the preparation of monomer, 3-methylthiothiophene was first synthesized through the metal-halogen exchange reaction of 3-bromothiophene with n-butyllithium, and the corresponding 2,5-dibromo-3-methylthiothiophene was formed by bromination. Their synthesis and characterization were determined by 1H-NMR and ATR analyses. Thermal stability of the oligothiophene was monitored by thermogravimetric analysis (TGA). Thermal evaporation of the oligo(3-methylthiothiophene) on the substrate was attempted for OTFT applications.

본 연구에서는 OTFT의 유기물 반도체 층으로 쓰일 수 있는 oligo(3-methylthiothiophene)를 전이금속 촉매인 palladium 촉매를 이용한 커플링 중합법을 이용하여 합성하였다. Thiophene 올리고머의 단량체를 합성하기 위해서 metal halogen exchange reaction에 의하여 3-methylthiothiophene를 합성하였고, thiophene 구조의 2, 5번의 위치에 brome기를 도입함으로써 최종적으로 2,5-dibromo-3-methylthiothiophene를 합성하였다. 합성된 단량체와 올리고머는 1H-NMR, ATR 분석을 통하여 그 구조를 확인하였으며, TGA로 열적 안정성을 관찰하였고 진공 증착법(thermal evaporation)을 이용하여 기판상에 증착시켜 OTFT 소재로서의 적용 가능성을 확인하였다.

Keywords: OTFT; thiophene; palladium; coupling