Solvent effects on the nitrogen screening of some nitroalkanes

High precision 14 N screening measurements are presented for some nitroalkanes. The screening increases as the dielectric constant of the solvent decreases in all cases considered. The β effect on the nitrogen screening is found to be largely independent of solvent, and is thus an intrinsic property of the nitroalkanes. Good agreement is obtained between the observed solvent effects on nitrogen screening and those calculated by the SOS procedure using INDO/S parameters. It is concluded that the measured nitrogen screening changes monitor the electronic changes which occur in the nitroalkanes as the medium is changed.