Three new structures of compounds containing the Re2(O2CR)2X4 unit are reported and two are shown to contain features rarely or not previously observed. Reaction of trimeric ReCl3 and PhCOONa in THF under reflux conditions for 24 h gave dark-green orthorhombic crystals of the THF solvate cis-Re2(O2CPh)2Cl4(THF)2·THF (1). The crystals belong to the space group Pbcm with unit cell dimensions a = 8.867(2), b = 19.851(4), c = 18.022(4) Å, V = 3172(2) Å3, and Dcalc = 2.037 g/cm3 for Z = 4. The structure was refined to R = 0.037 and Rw = 0.046 for 1825 reflections having I>3σ(I). Reaction of [(n-C4H9)4N]2Re2Cl8 and NaF in acetonitrile under reflux conditions for 4 days followed by work-up in acetone gave blue, monoclinic crystals of cis-[(n-C4H9)4N][Re2(O2CCH3)Cl5]· (CH3)2CO (2).The crystals belong to the space group P21/n with unit cell dimensions a = 11.283(4), b = 13.577(5), c = 21.835(10) Å, V = 3345(4) Å3, and Dcalc = 1.923 g/cm3 for Z = 4. The structure was refined to R = 0.056 and Rw = 0.066 for 2443 reflections having I>3σ(I). Compound 3, [ReCl2(dpcp)2][Re2(O2CPh)2Cl6]·CHCl3 contains the first example of an axially coordinated species with a transoid arrangement of the carboxylate ligands. 3 crystallizes in space group P1 with a = 13.372(4), b = 14.067(6), c = 10.899(7) Å, α = 99.694(5)°, β = 103.030(5)°, γ = 84.501(3)°, V = 1966(3) Å3, Z = 1. The structure was refined to R = 0.067 and Rw = 0.082 for 2648 reflections with I>3σ(I). © 1991.