Rotational isomerism in 2,2,3,3-tetranitrobutane

Abstract

I.r and Raman spectra of 2,2,3,3-tetranitrobutane (in solid and solution states) are reported and assignment of frequencies is made. Comparison of the Raman and i.r.spectra of solid and solution states shows that the compound exists as a mixture of gauche- and trans-rotamers in the solid, with the gauche predominating. Dipole moments in various 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, 2,2,3,3-tetranitrobutane exists as a rotameric mixture of 34%gauche and 66%trans in carbon tetrachloride solution, and 72%gauche and 28%trans in benzene solution. Solvent effects are also discussed.