Posts Tagged ‘Valence electron’
Sunday, March 4th, 2018
A bond index (BI) approximately measures the totals of the bond orders at any given atom in a molecule. Here I ponder what the maximum values might be for elements with filled valence shells.
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Tags:Atom, Chemical bond, chemical bonding, chemical properties, Chemistry, metal bond indices, Molecule, Nature, Quantum chemistry, Residential REITs, Resonance, Tennessine, Valence, Valence electron
Posted in Interesting chemistry | No Comments »
Thursday, March 2nd, 2017
The thread thus far. The post about Na2He introduced the electride anionic counter-ion to Na+ as corresponding topologically to a rare feature known as a non-nuclear attractor. This prompted speculation about other systems with such a feature, and the focus shifted to a tetrahedral arrangement of four hydrogen atoms as a dication, sharing a total of two valence electrons. The story now continues here.
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Tags:chemical bonding, Chemistry, Electride, free energy, Ion, Nature, Physical chemistry, Valence electron
Posted in Interesting chemistry | 1 Comment »
Sunday, September 11th, 2016
To quote from Wikipedia: in chemistry, a carbene is a molecule containing a neutral carbon atom with a valence of two and two unshared valence electrons. The most ubiquitous type of carbene of recent times is the one shown below as 1, often referred to as a resonance stabilised or persistent carbene. This type is of interest because of its ability to act as a ligand to an astonishingly wide variety of metals, with many of the resulting complexes being important catalysts. The Wiki page on persistent carbenes shows them throughout in form 1 below, thus reinforcing the belief that they have a valence of two and by implication six (2×2 shared + 2 unshared) electrons in the valence shell of carbon. Here I consider whether this name is really appropriate.
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Tags:Carbenes, chemical bonding, energy barrier, free energy, Functional groups, Ligand, Mesoionic carbene, Organometallic chemistry, Persistent carbene, quantum mechanical solution, Reactive intermediates, Transition metal carbene complex, Valence, Valence electron
Posted in crystal_structure_mining, General | No Comments »
Sunday, September 11th, 2016
To quote from Wikipedia: in chemistry, a carbene is a molecule containing a neutral carbon atom with a valence of two and two unshared valence electrons. The most ubiquitous type of carbene of recent times is the one shown below as 1, often referred to as a resonance stabilised or persistent carbene. This type is of interest because of its ability to act as a ligand to an astonishingly wide variety of metals, with many of the resulting complexes being important catalysts. The Wiki page on persistent carbenes shows them throughout in form 1 below, thus reinforcing the belief that they have a valence of two and by implication six (2×2 shared + 2 unshared) electrons in the valence shell of carbon. Here I consider whether this name is really appropriate.
(more…)
Tags:Carbenes, chemical bonding, energy barrier, free energy, Functional groups, Ligand, Mesoionic carbene, Organometallic chemistry, Persistent carbene, quantum mechanical solution, Reactive intermediates, Transition metal carbene complex, Valence, Valence electron
Posted in crystal_structure_mining, General | No Comments »