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:
“Is it not manifest that our academic institutions should have a wider scope; that they should not be timid and keep the ruts of the last generation, but that wise men thinking for themselves and heartily seeking the good of mankind, and counting the cost of innovation, should dare to arouse the young to a just and heroic life; that the moral nature should be addressed in the school-room, and children should be treated as the high-born candidates of truth and virtue?”
—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)