Carbon monoxide resonance energy

The resonance energy of carbon monoxide relative to the structure C=0 (which itself corresponds to resonance between + C 0 , C O , and C 0 ) can be found by comparing its heat of formation from atoms, 257 kcal/mole, with the ketone value of the doublebond energy, 174 kcal/mole.7 The very large difference, 83 kcal/mole,... 

Pauling, L. (1960). Resonant energy of carbon monoxide. In The Nature of the Chemical Bond and the Structure of Molecules and Crystals. An Introduction to Modem Structural Chemistry, 3rd edition, pp. 194-5. Cornell University Press, Ithaca. 

For the diatomic molecules that were studied—nitrogen, oxygen, nitric oxide, and carbon monoxide—the concept of a Coulomb explosion appears to be relevant. The yield of atomic ions is high, 93% to 97%, and the ion kinetic energies of around 7 eV for +1 ions and about twice this value for -1-2 ions are consistent with the Coulomb repulsion model. For the polyatomic molecules the situation is different. The yield of atomic ions drops to 85% for carbon dioxide and to 74% for carbo i tetrafluoride. For excitation of a core to bound state resonance in nitrous oxide, involving the terminal nitrogen atom, the yield of atomie ions is only 63% (Murakami et al. 1986). These molecules do not simply explode following excitation of a core electron. 

The large resonance energy of 58 kcal/mole stabilizes the molecule despite the lack of saturation of two carbon valences. For the physical properties of carbon monoxide, see the excellent review given by A. Smee-ton Leah [804]. 

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