Periodic trends in metal-metal bonding in cubane clusters, (C5H5)(4)M4E4 [M = Cr, Mo, E = O, S]

Trends in structure and bonding in a series of metal cubane clusters are examined using broken-symmetry density functional theory. For the metal-sulfur clusters, (C5H5)4Mo4S4 and (C5H5)4Cr4S4, the twelve cluster valence electrons are delocalised in six metal-metal single bonds, giving an approximate...