Computation of the conventional strain energy in oxaziridine

Conventional strain energy in the oxadiazetidines

“…Note that for all levels of theory and both basis sets, the isodesmic results differ greatly from the homodesmotic and the hyperhomodesmotic results. This failure of the isodesmic model to predict reliable strain energies is consistent with the results reported in each of our prior studies [37,38]. Also note that the strain energy would increase in every case if the ZPE correction were not included.…”

“…The highly correlated computations predict its conventional strain energy to be somewhere between 27.3 and 30.5 kcal/mol. This makes it more strained than cyclobutane, with a conventional strain energy between 26.0 and 27.3 kcal/mol [38] and slightly more strained than cyclopropane, at 27.5 to 28.6 kcal/mol of conventional strain energy [38]. The mostly highly strained system ex- One explanation for why cis-1,2,3-oxadiazetidine may be more strained than trans-1,2,3-oxadiazetidine is that in the former system there are two different instances where bonds from the ring to a hydrogen eclipse each other; in the latter there is only one.…”

“…Although that study showed that 1,2-oxazetidine is slightly more strained than is 1,3-oxazetidine and that both isomers are more strained than cyclobutane, some aspects of the computational methods need to be improved: harmonic frequencies and the resulting zero-point energy corrections were determined differently for the two isomers, larger basis sets were restricted to single-point calculations, none of the computations included d functions on the hydrogens, and density functional theory was not considered. Our second effort, published in 2002, was a more thorough study on the conventional strain energy in the threemembered system oxaziridine [38]. The current study builds upon these two previous studies by computing the conventional strain energy for cis-1,2,3-oxadiazetidine ( Fig.…”

Theoretical Insight into the Structure, Energetic Property and Thermal Stability of C6N6H12 Cages

“…The assessment of ring strain energy in ring compounds has been a topic of major interest to the organic chemist for decades [49][50][51][52][53][54][55][56][57][58]. Studies have proved that computational results of SE at the B3LYP/6-31G+(d,p) via homodesmotic process are reasonable [22,23,37,38,59] ) [61].…”

Three‐Membered Heterocycles. Structure and Reactivity

“…The conventional strain energy (CSE) for the parent compound has been calculated at 27.6 kcal mol À1 , lying between those of cyclopropane and cyclobutane [762]. Each bond in the ring is unique, with lengths ranging from 1.40 A (CÀO) to 1.50 A (NÀO).…”