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

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Abstract
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.