Rotational isomerism in 2,3-dinitro-2,3-dimethylbutane

Abstract

I.r. and Raman spectra of 2,3-dinitro-2,3-dimethylbutane (in the solid and solution states) are reported and assignments of frequencies made. Comparison of the Raman and i.r. spectra of the solid shows that the compound exists in the graucae-conformation in the solid state. Dipole moments in different solvents (benzene, carbon tetrachloride, dioxane, and cyclohexane) at different temperatures and molar Kerr constants (in carbon tetrachloride and benzene) are also reported. Analysis of the physical data shows that, at 25°C, 2,3-dinitro-2,3-dimethylbutane exists as a rotameric mixture of 42% gauche and 58% trans in carbon tetrachloride solution, and 79% gauche and 21% trans in benzene solution. Solvent effects are also discussed.