Depto. Química Orgánica

PHYSICAL AND BOND PROPERTIES OF CARBONYL COMPOUNDS

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15/07/2017
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Physical and bond properties of carbonyl compounds
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Like a double C=C bond, the carbonyl group C=O is formed from two molecular orbitals, one sigma and another pi.

The oxygen cannot bond to another atom and bears a couple of electron lone pairs in sp2 orbitals.
Oxygen's higher electronegativity induces a strong polarization of the C=O bond that marks its reactivity.
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Image Structural features of acetaldehyde
The experimentally measured bond angles and distances are compatible with a sp2 hybridization of the two atoms forming the C=O bond.
The charge-saparated resonance form explains the electron defficiency that carbon abides in a double C=O bond. This is an important difference with the C=C counterpart.
Oxygen's higher electronegativity induces a strong polarization of the C=O bond that marks its reactivity and, very IMPORTANT, that of its adjacent position (alpha).
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