Effect of Meta-Substitution on Solid State Geometry of N-(Aryl)-2,2,2-trichloro-acetamides, 3-XC6H4NH-CO-CCl3 and 3,5-X2C6H3NH-CO-CCl3 (X = Cl, CH3)

Abstract

The crystal structures of N-(meta-substituted phenyl)-2,2,2-trichloro-acetamides such as N- (3-methylphenyl)-2,2,2-trichloro-acetamide, 3-CH3C6H4NH-CO-CCl3 (3MPTCA); N-(3-chlorophenyl)- 2,2,2-trichloro-acetamide, 3-ClC6H4NH-CO-CCl3 (3CPTCA); N-(3,5-dimethylphenyl)- 2,2,2-trichloro-acetamide, 3,5-(CH3)2C6H3NH-CO-CCl3 (35DMPTCA) and N-(3,5-dichlorophenyl)- 2,2,2-trichloro-acetamide, 3,5-Cl2C6H3NH-CO-CCl3 (35DCPTCA) have been determined at room temperature. The crystal system, space group, formula units and lattice constants (Å ) of the new structures are: 3MPTCA: orthorhombic, Pbca, Z = 8, a = 12.3199(11), b = 8.9719(8), c = 20.2058(15); 3CPTCA: orthorhombic, Fdd2, Z =16, a=19.285(4), b=40.765(8), c=5.5920(11); 35DMPTCA: triclinic, P1̄, Z = 2, a = 8.994(4), b = 9.9890(10), c = 14.760(5), α = 79.56(2)°, β = 73.32(3)°, γ = 86.47(2)°; and 35DCPTCA: orthorhombic, Pbca, Z = 8, a = 22.485(5), b=10.738(2), c=10.028(3). The compound 35DMPTCA has two molecules in its asymmetric unit, similar to o-NO2-, m-NO2- and p-CH3-substituted phenyl-trichloro-acetamides, while 3MPTCA, 3CPTCA and 35DCPTCA have one molecule each in their asymmetric units. The analysis of data indicates that the substitution of a strong electron withdrawing group such as a nitro group into PTCA at ortho or meta positions has a significant effect on the crystal parameters.