The charge-transfer reaction of decamethylferrocene, Fe(C/sub 5/Me/sub 5/)/sub 2/, Fc*, and 7,7,8,8-tetracyano-p-quinodimethane, TCNQ, has been characterized. Three major reaction products of varying stoichiometry, conductivity, and magnetism are formed: a 1-D metamagnetic 1:1 salt, (Fc*)/sup +/(TCNQ)/sup -/; a paramagnetic (Fc*)/sup 2/ /sup +/(TCNQ)/sup 22 -/; 1:1; dimeric salt, (Fc*)/sup 2/ /sup +/(TCNQ)/sup 22 -/; and a conducting 1:2 salt of (Fc*) /sup +/(TCNQ)/sup 2 -/ composition. The crystal and molecular structures of the 1:1 paramagnetic dimeric and metamagnetic one-dimensional salts were solved. The ions in the dimeric phase crystallize in the centrosymmetric monoclinic space group P2/sub 1//c with a = 9.708 (1) A, b = 12.211 (2) A, c = 23.585 (4) A, ..beta.. = 95.01 (1)/sup 0/, Z = 4, and R = 0.058 for 3665 independent reflections. The magnetic susceptibility of powder samples of (Fc*)/sup 2/ /sup +/(TCNQ/sub 2/)/sub 2//sup 2 -/ obeys the Curie expression above 1.5 K suggesting very little magnetic coupling between the intradimer S = 1/2 Fe(III)'s which are separated by approx.14 A. The (TCNQ)/sub 2//sup 2 -/ dimer is strongly antiferromagnetically coupled. Ions in the linear chain metamagnetic phase crystallize in the centrosymmetric triclinic space group P1 vector. The unit cell at -106 /supmore » 0/C is a = 8.635 (4) A, b = 9.384 (6) A, c = 10.635 (9) A; ..cap alpha.. = 116.76 (5)/sup 0/, ..beta.. = 112.58 (5)/sup 0/; ..gamma.. = 72.49 (4)/sup 0/, V = 701.8 A/sup 3/, Z = 1, and R/sub w/ = 0.060 for 1156 reflections. The one-dimensional phase exhibits metamagnetic properties with a Neel temperature of 2.55 K. The intrachain Fe/sup III/-Fe/sup III/separation is 10.540 A. The calculated structure and scaled vibrational frequencies are in excellent agreement with the observed values.« less