Destabilizing energy

The rectangular structure is calculated to be strongly destabilized (antiaromatic) with respect to a polyene model. With 6-3IG calculations, for example, cyclobutadiene is found to have a negative resonance energy of—54.7 kcal/mol, relative to 1,3-butadiene. In addition, 30.7 kcal of strain is found, giving a total destabilization of 85.4 kcal/mol. G2 and MP4/G-31(d,p) calculations arrive at an antiaromatic destabilization energy of about 42kcal/mol. ... 

If the doubly occupied MO s, i and 0j, are degenerate the four electron destabilization energy is given by the equation ... 

Accordingly, the four electron destabilization energy will vary in the following order cis > trans > gauche. 

We expect that the stabilizing and destabilizing energies in the A + (B + C) union will dominate these same energies in the (B + C) union since the overlap integrals in the former case will be larger than those in the latter. 

The enthalpies of formation for nitrated anilines are listed in Table 5 and their destabilization energies are given in Table 6. Also included are the related compounds with additional amino groups, diaminotrinitrobenzene (DATB, 56) and triaminotrinitrobenzene (TATB, 57). Their destabilization energies are calculated from equations 59 and 60 ... 

The enthalpies of formation for nitrated toluenes are listed in Table 7 and then-calculated destabilization energies are given in Table 8. One polynitrotoluene, 2,4,6-trinitrotoluene, is the well-known explosive TNT (61). 

The estimation of aromatic stabilization (antiaromatic destabilization) energy based on thermodynamic characteristics of different reactions may yield for the same compound quite dissimilar values. As has already been pointed out, these discrepancies stem from the fact that the cyclic electron... 

The thermodynamic quantities listed in Table IX together with destabilization energies Ea of the unexcited excimer configuration computed as (Fig. 2)... 

Bromine is larger than chlorine, yet the two atoms have identical axial destabilization energies. Explain. 

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