2-Dicyanomethylene-1,3-Indanedione: A New Electron Acceptor

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Science  21 Jul 1967:
Vol. 157, Issue 3786, pp. 314-316
DOI: 10.1126/science.157.3786.314


The electron affinity of 2-dicyanomethylene-1,3-indanedione (I) (1.33 ev), as computed from charge-transfer spectral analysis and from polarographic measurements of half-wave reduction potential, shows that the incorporation of the 2-dicyanomethylene moiety in 1,2,3-indanetrione (II) enhances its π-acid character. The electron spin resonance spectrum of the anion radical of I, generated electrolytically in solution, shows hyperfine structure that is due to two nitrogen atoms and four equivalent hydrogen atoms.