The Molar Kerr constants and anisotropic polarisabilities of certain sterically hindered aromatic nitro-compounds

Abstract

The Molar Kerr constants and dipole moments, measured at infinite dilution in benzene, of the polar substances 1,4-dibromo-2-nitrobenzene, 1,3,5-tribromo-2-nitrobenzene, 1,3,5-trichloro-2-nitrobenzene, 1,2,4,5-tetramethyl-3,6-dinitrobenzene, 4-acetyl-1-t-butyl-3,5-dimethyl-2,6-dinitrobenzene, 1-t-butyl-3,5-dimethyl-2,4,6-trinitrobenzene, 1-nitronaphthalene, and 1,8-dinitronaphthalene are recorded. Molar Kerr constants and dielectric polarisations in benzene solution are also reported for the non-polar molecules p-dibromobenzene, 1,3,5-tribromo-benzene, 1,3,5-trichlorobenzene, and naphthalene. The anisotropic polarisabilities of the C–NO₂ group derived from aliphatic and aromatic environments are used in conjunction with the polarisability tensor specifications of certain basic structural units in a discussion of the conformation of the aromatic nitro-compounds mentioned. The results are in general agreement with predicted steric and electromeric effects.