Posts Tagged ‘Octet rule’
Sunday, February 21st, 2016
Hypervalency is defined as a molecule that contains one or more main group elements formally bearing more than eight electrons in their valence shell. One example of a molecule so characterised was CLi6[1] where the description "“carbon can expand its octet of electrons to form this relatively stable molecule“ was used. Yet, in this latter case, the octet expansion is in fact an illusion, as indeed are many examples that are cited. The octet shell remains resolutely un-expanded. Here I will explore the tiny molecule CH3F2- where two extra electrons have been added to fluoromethane.
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References
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H. Kudo, "Observation of hypervalent CLi6 by Knudsen-effusion mass spectrometry", Nature, vol. 355, pp. 432-434, 1992. http://dx.doi.org/10.1038/355432a0
Tags:Antibonding molecular orbital, Atomic orbital, Block, chemical bonding, Covalent bond, energy, Hypervalency, Hypervalent molecule, hypervalent systems, Molecular orbital, Molecular orbital diagram, Octet rule, Periodic table, Valence
Posted in Bond slam | 1 Comment »
Saturday, January 16th, 2016
The post on applying VSEPR ("valence shell electron pair repulsion") theory to the geometry of ClF3 has proved perennially popular. So here is a follow-up on another little molecue, F3SN. As the name implies, it is often represented with an S≡N bond. Here I take a look at the conventional analysis.
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Tags:Chemical bond, chemical bonding, Electron, Hypervalency, Lone pair, Molecular geometry, Octet rule, Quantum chemistry, Stereochemistry, Tetrahedral molecular geometry, Theoretical chemistry, Valence, VSEPR theory
Posted in Uncategorised | 110 Comments »