Influence of the nature of substituents in nitrobenzene derivatives on spectral characteristics of the Nitro Group

Reduction potentials of para‐substituted nitrobenzenes—an infrared, nuclear magnetic resonance, and density functional theory study

“…Experimentally measured asymmetric NO 2 stretching frequencies ( ν as ) are listed in Table . These attenuated reflection IR para ‐nitrobenzene data compare well with published IR data obtained in solvents, that is, dilute CCl 4 and CHCl 3 (Supporting Information: Table S3). Comparison of the IR spectra of the para ‐nitrobenzenes in the region 1600–1200 cm −1 (Fig.…”

“…The nitro group in para ‐nitrobenzene has a very pronounced polar character, with a dipole moment of 3.5–4.0 D depending on the nature of the substituent. The nitro group is characterized in an IR spectrum mainly by two high‐intensity and well‐formed stretching vibrations, asymmetric ( ν as ) and symmetric ( ν s ), giving rise to bands in the regions 1500–1570 cm −1 and 1300–1370 cm −1 , respectively .…”

“…This phenomenon impelled us to further investigate physically measurable quantities such as NMR chemical shifts and IR stretching frequencies, both being affected by electron density on the nitro group. Interspersed CV, [5,7,8,[29][30][31] NMR, and IR [32][33][34] data involving nitrobenzenes have been published, but a complete set of data done under uniform experimental conditions was needed for this study.…”