• Jacob Shamir

      Articles written in Journal of Chemical Sciences

    • Infrared and Raman spectra of 2,4-dimethylaniline

      A R Shukla C M Pathak N G Dongre B P Asthana Jacob Shamir

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      The infrared spectra of 2,4 dimethylaniline have been recorded in the region 3600-100 cm−1. The Raman spectra with polarization measurements have been recorded and investigated for the first time in the region 3500-100 cm−1. New frequency assignments have been proposed assuming the molecule to possess an approximateC2 symmetry. Fifty normal modes of the molecule, out of a possible fifty four modes, have actually been observed and assigned including twenty seven hitherto unreported frequencies. The observed spectral changes give evidence of the presence of an intermolecular hydrogen bonding of an N−H...N type, and suggest a solid-solid phase transition between 223 and 123 K in the molecule.

    • Infrared and Raman spectra of vicinally trisubstituted 2-methyl, 3-chloroaniline and 2-methyl, 6-chloroaniline

      A R Shukla C M Pathak N G Dongre B P Asthana Jacob Shamir

      More Details Abstract Fulltext PDF

      The IR and Raman spectra of 2-methyl, 3-chloroaniline (2-M, 3-CA) and 2-methyl, 6-chloroaniline (2-M, 6-CA) have been recorded at room temperature in the region 3600-100 cm−1. A vibrational analysis has been made using additional frequencies obtained from IR studies at 223 and 123 K and also including the polarization measurement of the Raman lines. A comparative study of these two molecules together with the spectra of 2,3-dimethylaniline (2,3-DMA), investigated earlier, has been presented. The anomalous behaviour of certain normal modes at low temperatures indicates the presence of an intermolecular hydrogen bonding of the N-H…N type in 2-M, 3-CA and 2,3-DMA, whereas, in 2-M, 6-CA, an intramolecular hydrogen bonding of the type N-H…Cl has been detected owing to the presence of the highly electronegative Cl atom at the ortho position.

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