Clusters cubanoid

Figure 2 Simplified MO energy pattern for cubanoid (P3-X)4M4L4 clusters, emphasizing the key MOs B, N, A. The numerals give the number of MOs of each type, and the symmetry symbols are for point-group Tj...

The (I) - (II) conversion involves replacement of some ligand-bridged connections with terminal ligands, resulting in isolation of a molecular fragment of the non-molecular precursor. Many examples are found in the formation of cubanoid clusters (equation 8 M = Cu, Ag X = Cl, Br, I) ... 

The [Pb404Pb4] + cluster embedded in Br ions occurs in the compounds TlPbg04Br9 and Pb904Brio. It can be regarded as a tetracapped tetrahedron (Pbin er)4(Pbouter)4 with O atoms within the caps, or as cubanoid Pb404 with Pb atoms extended beyond O on the body diagonals. 

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