Rotational isomerism in 2,3-dimethyl-2,3-dinitropentane

Abstract

IR and Raman spectra of 2,3-dimethyl-2,3-dinitropentane (in the solid and solution states) are reported and assignment of frequencies made. Comparison of the Raman and IR spectra in both the solid and solution states shows that the compound exists in two polar gauche conformations in the solid state and as a rotameric mixture of the gauche and non-polar trans conformers in solution. Analysis of dipole moment data shows that in carbon tetrachloride at 25°C, the rotameric mixture contains approximately 67% trans and 33% of the combined polar gauche rotamers. In benzene and dioxane, the combined gauche population substantially exceeds that of the trans. © 1989.