Modeling Biological Copper Clusters: Synthesis of a Tricopper Complex, and Its Chloride- and Sulfide-Bridged Congeners

作者：Di Francesco Gianna N; Gaillard Aleth; Ghiviriga Ion; Abboud Khalil A; Murray Leslie J^*

来源：Inorganic Chemistry, 2014, 53(9): 4647-4654.

DOI：10.1021/ic500333p

The synthesis and characterization of a family of tricopper clusters housed within a tris(beta-diketimine) cyclophane ligand (H3L) that bear structural similarities to biological copper clusters are reported. In all complexes, each Cu atom is held within the N-2-chelate of a single beta-diketiminate arm. Reaction of L3- with CuCl affords an anionic complex containing a mu(3)-chloride donor in the central cavity, whereas there is no evidence for bromide incorporation in the product of the reaction of L3- with CuBr (Cu3L). Cu3L reacts with elemental sulfur to generate the corresponding air-stable mixed-valent (mu(3)-sulfido)tricopper complex, Cu-3(mu(3)-S)L, which represents the first example of a sulfide-bridged copper cluster in which each metal center is both coordinatively unsaturated and held within a N-rich environment. The calculated LUMO is predominantly Cu-S pi* in character and delocalized over all three metal centers, which is consistent with the isotropic ten-line absorption (g similar to 2.095, A similar to 33 G) observed at room temperature in EPR spectra of the one-electron chemically reduced complex, [Cu-3(mu 3-S)L](-).

• 出版日期2014-5-5