SPECTROSCOPIC INVESTIGATIONS OF THE UNUSUAL GIANT CLUSTER ANION [MO57FE6(NO)6O174(OH)3(H2O)24]15- CONTAINING 276 NON-HYDROGEN ATOMS

Müller A, PLASS W. SPECTROSCOPIC INVESTIGATIONS OF THE UNUSUAL GIANT CLUSTER ANION [MO57FE6(NO)6O174(OH)3(H2O)24]15- CONTAINING 276 NON-HYDROGEN ATOMS. JOURNAL OF MOLECULAR STRUCTURE. 1994;321(3):215-223.The X-ray single crystal structure determination of the compound Na3(NH4)12[Mo57Fe6(NO)6O174(OH)3 (H2O)24].76H2O, containing a doughnut-shaped giant cluster anion, shows that additional physical methods have to be applied in order to establish its structure. In fact, this situation is generally found for compounds with large molecular cluster assemblies. The detailed spectroscopic studies presented here promote the formulation [{Fe(H2O)2}6{Mo(mu-H2O)2(mu-OH)Mo}3{Mo15(MoNO)23+O58(H2O)2}3]15-for the cluster anion, which is composed of three transferable {Mo17} ligands bridged by cationic centres. They also provide evidence for the remarkable electronic properties expected for such a giant cluster anion with several interacting open shell metal centres