NQR Spectra of Substituted N-(phenyl)-2-chloroacetamides

Fifteen methyl-, nitro-, or mixed substituted N-(phenyl)-2-chloroacetamides were investigated by C1 NQR. The temperature dependence of the frequencies of the 3-methylphenyl and 2,6-dimethylphenyl derivatives were studied for the range 77 K<T<300 K. Only one co C-Cl frequency was observed for the compound with the two exceptions. For N-(2-nitro,4-chlorophenyl)-2-chloroacetamide the observed values of 35.623 and 35.350 MHz were assigned to ft) C-C 1 and ring C-Cl, whereas the corresponding values are 36.254 and 34.815 MHz for N-(2-methyl, 3-chlorophenyl)-2-chloroacetamide. The experimental frequencies of all compounds have been compared with values estimated from NQR substituent parameters and the frequency of N-(phenyl)-2-chloroacetamide. The agreement is remarkably good with a maximum deviation of 1.64 MHz. Furthermore y(Cl) of all compounds has been correlated with X k, and with the Hammett constants.