Energetics of HF Elimination and N-F Bond Cleavage in Some Difluoramines and Gem-Nitro/Difluoramines.
Abstract
We have shown, through density functional calculations (Becke exchange/Lee, Yang and Parr correlation functionals, 6-31G** basis set) that the elimination of HF from H3C-NF2 is thermodynamically favored, Delta G(298.15 K) = -29 kcal/mole, but has a relatively high activation barrier, Delta G(double dagger)(298.15 K) = 38 kcal/mole. The N-F dissociation energy, Delta E sub(N-F), is found to be 69 kcal/mole. Introduction of a nitro group, giving H2C(NO2)NF2, produces only small changes in these values: Delta G(298.15 K) = -28 kcal/mole; Delta G(double dagger)(298.l5 K) = 36 kcal/mole; Delta E sub(N-F) = 66 kcal/mole. Replacement of all alpha hydrogens by methyl groups increases the N-F dissociation energies slightly (<2 kcal/mole). These substituent effects are interpreted in terms of geminal interactions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 05, 1996
- Accession Number
- ADA310958
Entities
People
- M. Edward Grice
- Pat Lane
- Peter Politzer
Organizations
- University of New Orleans