Bond energies in the interpretation of descriptive chemistry

Abstract

Bond energy calculations are ordinarily covered in an introductory chemistry course, but then very little use is made of them. Thus, most textbooks give a table of single bond energies and illustrate its use for a few simple carbon compounds. Then bond energies may be used in a calculation of the resonance energy in some molecule such as benzene, but they are almost never mentioned in connection with the chemistry of any elements except carbon. Very few of the tabulations even attempt to list an N-0 or S O bond energy.This situation is easily understandable since the standard treatment of bond energies gives useful results only for stable molecules with nealieible ~i bond reso-CH,, and NH together with the fact that an even number is easier to use here than an odd one.

Solid State Properties of Some Valve Metal Oxides

“…If the spin correlation stabilization energies, which are usually small, are ignored (20), the heats of atomization (Table II) per equivalent would be identical to the average bond energies (not bond dissociation energies for particular bonds). An attempt has also been made here to calculate the MO (metal-oxide) bond energies for these oxides, by taking into account spin correlation stabilization energies (20).…”

Influence of Bond Energies of Oxides on the Kinetics of Anodic Oxide Growth on Valve Metals

“…The bond energies (Table I) for the various valve metal oxides ha~ie been calculated by the procedure of Howald (3). The procedure essentially involves obtaining heats of atomization per equivalent for various oxides by taking into account spin correlation stabilization energies.…”

“…The quantity thus obtained is an average bond energy value. In our computations, presence of any coordinate bonds has been ignored since unambiguous estimates of their contribution are not always readily accessible, as discussed by Howald (3).…”

Position orbital calculations of energy levels for p-block atoms

“…The experimental evidence for the particular stability of high spin half-filled subshells is clear and convincing. Gray (1) has shown how to find term symbols for the allowed states in an elementary fashion, and spin correlation stabilization energies can be easily calculated using the formula, SCSE = D(n)(n -1), where n is the number of electrons with parallel spins (2,3). This equation actually gives the energy difference between the average of all states for the configuration and the average of all states of maximum multiplicity, but in most cases, this is close to the energy difference between the ground state and the overall average.…”

“…For calculations of bond energies, I have recommended a constant value of D = 8 kcal mole-1 = 0.034 MJ mole-1 for the 2p subshell (2). For calculations of energy levels for atoms and ions with partly filled 2p subshells it is clearly better to recognize explicitly that the spin correlation stabilization energy increases with increasing atomic number, Z, and increasing charge, Q.…”