A cluster-ligand is disclosed in the form of [Ru 3 (CN) 3 (CO) 9 ] 3- ([ 1 ] 3- ). Produced by simple reaction of [Ru 3 (CO) 12 ] with cyanide, [ 1 ] 3- serves as a precursor to a series of μ-CN cages. When treated with [Ru 3 (CO) 12 ], it readily forms the prism [Ru 6 (μ-CN) 3 (CO) 18 ] 3- . With 1.5 equiv of [Cu(MeCN) 4 ] + [ 1 ] 3- reacts to give the expanded prism {Cu 3 [Ru 3 (μ-CN) 3 (CO) 9 ] 2 } 3- , which features three two-coordinate Cu(I) centers. Sources of Ni 2+ and Fe 2+ bind two equivalents of [ 1 ] 3- , giving the double cages {M[Ru 3 (μ-CN) 3 (CO) 9 ] 2 } 4- (M = Ni, Fe) wherein the central metal is octahedral. The 1:1 reaction using [Fe(H 2 O) 6 ] 2+ gave the interpenetrated super-tetrahedrane {Fe 4 (μ 4 -O)[Ru 3 (μ-CN) 3 (CO) 9 ] 4 } 4- .