Synthesis and Charge/Discharge Properties of Polyacetylenes Carrying 2,2,6,6-Tetramethyl-1-piperidinoxy Radicals

The 2,2,6,6‐tetramethyl‐1‐piperidinoxy (TEMPO)‐containing acetylenic monomers HCCC6H3‐p,m‐(CONH‐4‐TEMPO)2 (1), HCCC6H3‐p,m‐(COO‐4‐TEMPO)2 (2), (S,S,S,S)‐HCCC6H3‐p,m‐[CO‐NHCH{COO‐(4‐TEMPO)}CH2COO‐(4‐TEMPO)]2 (3), (S,S)‐HCCC6H4CO‐NHCH{COO‐(4‐TEMPO)}CH2COO‐(4‐TEMPO) (4), HCCC6H4‐p‐OCO‐4‐TEMPO (5), HCCCH2C(CH3)(CH2OCO‐4‐TEMPO)2 (6), HCCCH2NHCO‐4‐TEMPO (7), and HCCCH2OCO‐4‐TEMPO (8) were polymerized to afford novel polymers containing the TEMPO radical at high densities. Monomers 1, 3–6, and 8 provided polymers with average molecular weights of 10 000–136 500 in 62–99 % yield in the presence of a rhodium catalyst, whereas monomers 2 and 7 gave insoluble polymers in 100 % yield. The formed polymers were thermally stable up to approximately 274 °C according to thermogravimetric analysis (TGA). All the TEMPO‐containing polymers demonstrated reversible charge/discharge processes, whose discharge capacities were 21.3–108 A h kg−1. In particular, the capacity of poly(1)‐, poly(4)‐, and poly(5)‐based cells reached 108, 96.3, and 89.3 A h kg−1, respectively, which practically coincided with their theoretical values. Radical behavior! 2,2,6,6‐Tetramethyl‐1‐piperidinoxy (TEMPO)‐containing acetylenic monomers polymerize to afford novel polymers containing the TEMPO radical at high densities. All the TEMPO‐containing polymers demonstrate reversible charge/discharge processes (see scheme), with discharge capacities of 21.3–108 A h kg−1.