Electron Counting in Octahedral Clusters
The species Mo6Cl142- feature Mo(II) (d4) centers. Six Mo(II) centers gives rise to a total of 24 valence electrons, or 2e/Mo-Mo vector. More electron-deficient derivatives such as Ta6Cl184- have fewer d-electrons. For example, the naked cluster Ta6+14, the core of Ta6Cl184- would have 5(6) - 14 = 16 valence electrons. Fewer d-electrons result in weakened M-M bonding and the extended Ta---Ta distances accommodate doubly bridging halides.
Read more about this topic: Octahedral Cluster
Famous quotes containing the words counting and/or clusters:
“What we commonly call man, the eating, drinking, planting, counting man, does not, as we know him, represent himself, but misrepresents himself. Him we do not respect, but the soul, whose organ he is, would he let it appear through his action, would make our knees bend.”
—Ralph Waldo Emerson (1803–1882)
“What wondrous life in this I lead!
Ripe apples drop about my head;
The luscious clusters of the vine
Upon my mouth do crush their wine;
The nectarine and curious peach
Into my hands themselves do reach;
Stumbling on melons, as I pass,
Ensnared with flowers, I fall on grass.”
—Andrew Marvell (1621–1678)