Stefano Zacchini, Roberto Della Pergola, Piero Zanello, Carlo Manassero, Luigi Garlaschelli, Donatella Strumolo, Francesco Kaswalder, Serena Fedi, Mario Manassero, Annalisa Sironi, DELLA PERGOLA, R, Sironi, A, Garlaschelli, L, Strumolo, D, Manassero, C, Manassero, M, Fedi, S, Zanello, P, Kaswalder, F, and Zacchini, S
The reactions between [Fe 6 C(CO) 16 ] 2− and CuCl, in refluxing THF, yield [Fe 5 C(CO) 14 (CuCl)] 2− ( 1 ), [Fe 4 C(CO) 12 (CuCl) 2 ] 2− ( 2 ), or [{Fe 4 Cu 2 C(CO) 12 (μ-Cl)} 2 ] 2− ( 3 ), depending on the Fe 6 /CuCl ratio. The chloro ligands of these clusters can be displaced either spontaneously, or by metal-assisted substitution, to give the bromo derivative [Fe 5 C(CO) 14 (CuBr)] 2− ( 4 ) or the solvento complexes [Fe 5 C(CO) 14 (CuTHF)] − ( 5 ) and [Fe 4 C(CO) 12 (CuNCMe) 2 ] ( 6 ). The latter can be also obtained directly, by metal substitution from [Fe 6 C(CO) 16 ] 2− and [Cu(NCMe) 4 ]BF 4 , or by polyhedral expansion from [Fe 4 C(CO) 12 ] 2− . All the clusters are octahedral, with the copper atoms in a pseudo-linear geometry, where one of the coordination positions is occupied by the interstitial carbide. The two copper atoms in the Fe 4 Cu 2 clusters are always in cis geometry and, in the dimer [{Fe 4 Cu 2 C(CO) 12 (μ-Cl)} 2 ] 2− , they are joined through chlorides. The role of the different metal centres in determining the redox activity of the heteronuclear Fe–Cu clusters 1 , 2 , 3 , has been studied by electrochemical methods. In the bridged dimer 3 , the two Fe 4 Cu 2 C cluster units resulted electronically not communicating.