Sulfonamidyls, 4. Ab Initio MO Calculations on Sulfonyl and Carbonyl Substituted Aminyl Radicals

Abstract

<jats:title>Abstract</jats:title><jats:p> The relative magnitude of the nitrogen hyperfine splitting constants of sulfonamidyls and carboxamidyls is rationalized in terms of the results of ab initio MO calculations using the "double zeta" basis set of Roos and Siegbahn.</jats:p>

Photoinduced Rearrangement of AromaticN-Chloroamides to Chloroaromatic Amides in the Solid State: Inverted ΠN–ΣNOccupational Stability of Amidyl Radicals

“…A substantial amount of experimental evidence exists showing that, similar to the related aminyl radicals, the Π N radical state, which has the unshared electron pair in the N sp 2 hybrid orbital and the unpaired electron in the orthogonal N p orbital, is the actual ground state of the acyclic amidyls as well as of the succinimidyl radical (Figure a) . Although the Π N state of the acyclic amidyl radicals is preferred over the Σ N state, as it has been demonstrated in the pioneering work of Lessard and others, steric constraints (e.g., tert -butyl substitution) as well as other geometric factors can decrease the Π–Σ gap significantly, leading to nearly equal probability for population of both available orbitals with the unpaired electron or to mixing of the occupational states. The probability of state quasidegeneracy increases with the aromatic amidyls, where the electron/electron pair couple competes for resonance with the aromatic π-system .…”