Reactions of Co(PMe3)(3)Cl or CoCl2 with 3,5-(CF3)(2)-PzNa in hexane give Co(PMe3)(3)(3,5-(CF3)(2)-Pz) (1) and Co(PMe3)(3)(3,5-(CF3)(2)-Pz)(2) (2) respectively (3,5-(CF3)(2)-PzNa = sodium bis-trifluoromethylpyrazolate). Reaction of (3,5-(CF3)(2)-PzH) with Co(PMe3)(4) produces the unusual complex [cis-Co(PMe3)(4)H-2][Co(PMe3)(3,5-( CF3)(2)-Pz)(3)] (3) which formally contains a Co(III)Co(II) complex ion pair. Reaction of 3,5-(CF3)(2)-PzLi with an oxygenated suspension of CoCl2 and 3 equivalents of PMe3 gives (3,5-(CF3)(2)-Pz)(2)Co(mu-3,5-(CF3)(2)Pz)(mu-OPMe3)Li(OPMe3)(2) (4), while 2 reacts with LiOH to give (PMe3)Co(mu-3,5-(CF3)(2)-Pz)(2)(mu(3)-OH)Li (5). Both 2 and 3 react with O-2 in toluene solution to give Co(OPMe3)(2)(3,5-(CF3)(2)-Pz)(2) (6). All compounds have been characterized spectroscopically and by single crystal X-ray diffraction studies.