Synthesis, structure, and electrochemistry of N-(3-thenoyl)fluorosulfonimide and bis(2-thenoic)imide. Preparation of polymers containing the fluorosulfonimide group

N-(3-Thenoyl)fluorosulfonimide, (1), C4H3SC(O)N(H)SO2F, was prepared by the reaction of 3-thenoic acid with fluorosulfuryl isocyanate in acetonitrile solution. The new compound is a moderately strong nitrogen acid having a pKa of 2.4. Single-crystal X-ray structural analysis of (1) shows a pattern of strong intermolecular hydrogen-bonding, resulting in the formation of linear chains. (1) is electroinactive over a range of 2 V but undergoes hydrogen reduction (Ep/2c=−0.28 V). The salt of (1) with TBA+, 2, has been prepared and its crystal structure determined. The new dithienyl compound, bis(2-thienyl)imide, 3, has been prepared and crystallographically characterized. The polymers of 1, 3, and a polymer containing the fluorosulfonimide group formed from a copolymer of 3-methylthiophene/3-thiophene carboxylic acid are also reported.