The ferromagnet [FeCp2*][TCNE] (T-c = 4.80 K) has two structural phase transitions at 249 and 282 K that has thwarted the determination of its structure by single crystal X-ray diffraction; however, its structure at 100 K is reported [P2(1/c), a = 9.710(1) angstrom, b = 14.214(2) angstrom, c = 18.753(2) angstrom, beta = 113.207(2)degrees angstrom, V = 2378.7(5) angstrom(3), Z = 4, T = 100 K]. Because of the facile loss of solvent, the ferromagnetic solvates, [FeCp*(2)][TCNE] center dot yS {S = MeCN [y = 1, P, a = 9.556(2) angstrom, b = 9.781(2) angstrom, c = 16.152(2) angstrom, alpha = 74.860(2)degrees, beta = 84,333(3)degrees, gamma = 65.030(4)degrees, V = 1321.0(4) angstrom(3), Z = 2, T = 100 K), EtCN [y = 1/2, Pnma, a = 14.750(5) angstrom, b = 10.577(5) A, c = 33.972(10) angstrom, V = 5301(3) angstrom(3), Z = 8, T = 100 K], n-PrCN [y = 1/2, C2/m, a = 35.902(6) angstrom, b = 10.488(2) angstrom, c = 14.302(2) angstrom, beta = 101.396(3)degrees, V = 5279(1) angstrom(3), Z = 8, T = 173 K]} have also been difficult to crystallographically characterize, but have been determined from single crystal X-ray diffraction data. These structures consist of parallel chains of alternating [FeCp2*]center dot+ and [TCNE](center dot-) ions, with an intrachain Fe center dot center dot center dot Fe distance of 10.54 +/-0.09 angstrom. The solvates additionally possess chains of solvent that separate the alternating chains of (FeCp2*](center dot+) and [TCNE](center dot-) ions. The MeCN solvate forms layers of chains that separate two rows of chains, while the EtCN and n-PrCN solvates form chains surrounded by six chains, and have fewer nonmagnetic coupling pathways that result in higher ordering temperature with respect to the MeCN solvate.