The very reactive Rieke cadmium metal was allowed to react under vacuum with benzoquinone in tetrahydrofuran. This resulted in the formation of several different paramagnetic species whose EPR spectra prove them to have doublet multiplicities. The tetrahedral coordination sphere of each of these species consists of three THF molecules and an anion radical that is either asymmetrically coordinated or symmetrically coordinated to the metal dication. This latter species yields a Cd-111 hyperfine splitting of 6.86 G. The second anion radical lies outside this coordination sphere, and it can be either asymmetrically ion associated with or dissociated from the tetrahedral metal complex. FLU species have the general formula [Cd(C6H4O2.-)(THF)(3)](+),C6H4O2.-) or {[Cd(C6H4O2.-)(THF)(3)](+) + C6H4O2.-}.