Structure and Paramagnetism of Strong Charge-Transfer Complexes: 5.10-Dihydro-2.3.5.7.8.10-hexamethylphenazine-tetracyanoethylene (M6P) (TCNE)

The potent new donor 5.10-dihydro-2.3.5.7.8.10-hexamethylphenazine was synthesized and reacted with tetracyanoethylene to form a paramagnetic ionic charge transfer salt. The title compound (C18H22N2) (C6N4), (M6P) (TCNE), M r = 394.51, crystallizes in the monoclinic space group P21/n with a = 7.679(3) Å, b = 8.458(2) Å, c = 15.841(6) Å, β = 92.88(3)0, V = 1027.55 Å3, d c = 1.288 Mg m−3, and Z = 2. The planar M6P+ and TCNE− radical ions form mixed, regular stacks along b with a distance between M6P+ and TCNE− of 3.4(1) Å. Final refinement yielded R-indices of R = 0.092 and R w = 0.058. Epr and static susceptibility data are interpreted in terms of novel disorder involving specific TCNE-allyl exchanges.