The Bond N-Cl . (Ill): A C1 NQR and X-Ray Diffraction Study of N-Chloro-N-(2,6-Dichlorophenyl)-Acetamides *

The crystal structures at room temperature of the N-chloro-N-(2,6-dichlorophenyl)-chloroacetamides 2 ,6 -Cl 2 C 6 H 3 NClCOCCl 3 (1) and 2 ,6 -C l 2 C 6 H 3 NClCOCH 2 Cl (2) have been determined. (1): or thorhombic , Pbca. Z = 8, a = 2051.7(8) pm, b= 1134.8(4) pm, c = 1089.0(4) pm. (2): orthorhombic, Pbca, Z = S, a = 2078.7 (4) pm, b= 1487.9(4) pm, c = 694.0 (2) pm. The " C I N Q R spectrum of (1) was studied in the range 7 7 < T / K < 3 7 0 . At 77 K, a sextet spectrum is observed (v in MHz): vj = v(Cl ( N ) = 56.327; v2 = 40.636, v3 = 40.317, v4 = 40.294; v? = 36.532, v6 = 36.182. The lines v2 , v3 , and v4 are assigned to the CC13 group because of their position in the frequency scale. Also, due to librational motions, this triplet part of the spectrum fades out at 320 K. There is no problem in assigning in both compounds, on the basis of the known C1 N Q R frequency scale, the line Vj to the CI a tom attached to the nitrogen a tom and the lines v5 and v6 to the ring chlorines (Cl and Cl ). The crystal structures and N Q R spectra of (1) and (2) are discussed together with literature data for 2 , 6 C l 2 C 6 H 3 N H C O R , C 6 H 5 N C 1 C 0 R (where R = CC13 , C C l H 2 f a n d other substituted acetamides.