Electrosyntheses and Characterization of Poly-N-(9-Fluorenylmethoxycarbonyl)-L-isoleucine (PFI) with Chirality

Abstract

Poly-(N-(9-fluorenylmethoxycarbonyl)-L-isoleucine) (PFI) films with chirality were synthesized electrochemically by direct anodic oxidation of N-(9-fluorenylmethoxy- carbonyl)-L-isoleucine (FI) in a medium strong Lewis acid, boron trifluoride diethyl etherate (BFEE). The oxidation potential of FI in BFEE was only 0.6 V vs. Pt, which was much lower than that determined in acetonitrile + 0.1 mol L⁻¹ tetrabutylammonium tetrafluoroborate (TBATFB) (1.0 V vs. Pt). Results of FT-IR, UV–visible spectra and ¹H NMR spectra indicated that FI was polymerized successfully and the polymerization positions were C2 and C7. Results of electrochemical measurements showed PFI had good redox activity and stability. SEM provided the surface morphology of the PFI film. Result of thermogravimetric analyses (TG) indicated PFI films obtained from BFEE had good thermostability. As-formed PFI films can be dissolved in ethanol, N,N-Dimethylformamide(DMF), etc.

Keywords:

• boron trifluoride diethyl etherate (BFEE)
• chiral
• electrochemical polymerization
• poly-(N-(9-Fluorenylmethoxycarbonyl)-L-isoleucine) (PFI)
• solubility

Acknowledgments

Financial supports from the National Natural Science Foundation of China (Grant 50872042) and the Natural Science Foundation of Shandong province (Grant Y2008B61) are acknowledged.