Anionic Bismuth-Oxido Carboxylate Clusters with Transition Metal Countercations.

Six new anionic bismuth-oxido clusters containing trifluoroacetate ligands were prepared. These include two new Bi6 O8 clusters: [M(NCMe)2 (H2 O)4 ]3 [Bi6 (μ3 -O)4 (μ3 -OH)4 (CF3 CO2 )12 ] with an octahedral Bi6 O4 (OH)4 core (M = Ni, 1a; Co, 1b) and four Bi4 O2 clusters, {[Co(NCMe)6 ][Bi4 (μ3 -O)2 (CF3 CO2 )10 ]}n (2a), {[Co{HC(MeCO)2 (MeCNH)}2 ][Bi4 (μ3 -O)2 (CF3 CO2 )10 ]·2[CF3 CO2 ]·2[CF3 CO2 H]·2[H2 O]}n (2b), {[Cu(NCMe)4 ]2 [Bi4 (μ3 -O)2 (CF3 CO2 )10 ]·2[CF3 CO2 H]}n (2c), and {[Me4 N]2 [Bi4 (μ3 -O)2 (CF3 CO2 )10 ]·2[CF3 CO2 H]}n (2d). These are among the first bismuth-oxido anionic clusters synthesized, and the first to have transition metal countercations. The Bi6 O8 anion in 1a and 1b is a high-symmetry octahedron. Additionally, two of the new Bi4 O2 clusters are arranged in 1D polymeric structures via bridging carboxylate ligands. The cation in compound 2c had not been previously characterized and was also observed in the synthesis of [Co{HC(MeCO)2 (MeCNH)}2 ][Bi(NO3 )6 ] (3). The new compounds were characterized using single crystal X-ray crystallography and elemental analysis.