INFRARED STUDY OF SUBSTITUTED NITROBENZENES IN CARBON-TETRACHLORIDE AND CHLOROFORM SOLUTIONS

Both the νNO2 modes are affected by solute/solvent interaction for nitrobenzenes in CHCI3 and/or CCI4 1% or less solutions. The νsym.NO2 mode decreases in frequency in the order of physical phase: vapor, CCI4 solution, and CHCI3 solution. The νsym.NO2 mode generally increases in frequency in going from CCI4 solution to CHCI3 solution. However, in the few cases when the νsym.NO2 mode decreases in frequency, this frequency decrease is a factor of approximately 0.5 or less than the frequency decrease for νsym.NO2. In cases where a C=O or a SO2 group is also joined to the 4-nitrophenyl group, the SO2 or C=O group is also affected by solute/solvent interaction. Physical factors such as intermolecular hydrogen bonding, dipolar effects, chemical effects, and steric factors of both solute and solvent appear to be involved in determining the degree of solute/solvent interaction.