Tetranuclear [Cu-4(II)(OH)(4)( aib)(4))]( hfac) 4 ( 1; aib) 2-methyl-2-amino-4- iminopentane; hfac) hexafluoroacetylacetonate) forms from the reaction of aqueous ammonia and Cu(hfac)(2) center dot 2H(2)O in acetone. The structure of 1 reveals that four noncoordinating hfac(-) counterions stabilize the distorted cubane complex via multiple H-bonding contacts. Magnetic susceptibility studies reveal that cubane-like 1 is best described as a pair of independent antiferromagnetically coupled dimers with g = 2.10 and J/k(B) = - 298 K (207 cm(-1)) (H = - 2 JS(1) center dot S-2).