Synthesis of 1,1′-bicobaltocene salts of tetracyano-p-quinodimethanide and the structure of 1,1′-bicobaltocene[CoIIICoIII] tris(tetracyano-p-quinodimethanide)

Article abstract of DOI:10.1021/ic00131a038

The reaction of 1,1′-bicobaltocene[Co^IIICo^III](PF₆) ₂ or the analogous mixed-valence compound [Co^IIICo^II] with excess [(C₂H₅)₃NH][TCNQ]₂ and TCNQ yields the complex salt 1,1′-bicobaltocene[Co^IIICo^III][TCNQ]₃. The complex salt crystallizes in the triclinic system: space group P1 with unit cell dimensions a = 7.475 (4) ?, b = 10.113 (5) ?, c = 14.306 (3) ?, α = 92.51 (3)°, β = 98.84 (3)°, and γ = 92.64 (4)°. The conventional and weighted R factors for 1979 reflections for which 7 was greater than 3σ(I) are R = 0.047 and R_w = 0.044. The TCNQ units stack to form an alternating chain with two short, adjacent interplanar spacings of 3.15 ?, followed by a longer interplanar spacing of 3.45 ?. The interplanar spacing of the fulvalene moieties in the cation is 3.270 ?, and the cobalt-carbon bond distances range from 2.012 (5) to 2.041 (5) ?. The complex salt is diamagnetic, and the electrical conductivity of a pressed pellet sample is 0.03 Ω^-1 cm^-1.