Subject Number : S-17-NM-0034
Support Type : 機器利用
Proposal Title (English) : Design, Synthesis and Photophysical Properties of Novel π-Conjugated Bow Shaped Oligothiophene Unit
Username (English) : Naeem Karattuchali
Affiliation (English) : NIIST Trivandrum, Academy of Scientific and Innovative Research, INDIA.

1. Summary
Thiophene-based oligomers and polymers have been widely explored owing to their synthetic easiness, charge transporting properties and stability in their redox states. They represent a promising scaffold for π-electron materials for wide varieties of electronic devices such as organic light-emitting diodes, organic field-effect transistors, and photovoltaics. A number of linear oligothiophenes, cyclic oligothiophenes and macrocycles have recently attracted considerable attention due to their fascinating π-conjugation in the circular topology. In this work, we designed and synthesized novel bow shaped oligothiophene, which have eight rigid thiophene units and flexible nonyl chain via Palladium and Nickel mediated coupling reactions.

2. Experimental
1. NMR
2.Glove box
NMR tecnique was used for the characterisation of the precorsors and target compounds.
Glove box was used for the air and water sensitive synthetic procedures.

3. Results and Discussion
The air and water sensitive reactions are successfully conducted by using Glove box. The precursor with two quaterthiophen units were synthesized by Negishi coupling involving the usage of highly hygroscopic ZnCl2. We handled this reagent in the glove box with inert gas atmosphere. The target bow shaped oligothiophene was synthesized by Yamamoto coupling with highly air-sensitive bis(1,5-cyclooctadiene)nickel(0) complex. The molecular structures of all precursors and target compound were characterized by 1H NMR spectrometry and Mass spectrometry. The molecular structure and its packing structure of the target compound were finely confirmed by the single crystal X-ray diffraction. The photophysical properties of target compound, including absorption, emission spectra and fluorescence lifetime, suggests the bow shape structure can induce distinct electronic characters with conventional linear oligothiophene derivatives.

Fig. 1 Molecular structure of bow shape oligothiophene

4. Others
I acknowledge NIMS MMS Platform for allowing me to use the facility and Drs. Hattori and Li for technical assistants.

5. Publication/Presentation
N/A

6. Patent
N/A