The crystal and molecular structure of N-(6-chlorophthalan-1-ylidene)-1-(methylazo)cyclohexylamine

Abstract

The crystal and molecular structure of N-(6-chlorophthalan-1-ylidene)-1-(methylazo)cyclohexylamine, C₁₅H₁₈-CIN₃O, has been determined by a three-dimensional single-crystal X-ray diffraction study. This compound crystallizes in space group P2₁/c with lattice parameters a= 7·990 ± 0·006, b= 10·812 ± 0·011, c= 16·987 ± 0·018 Å, and β= 91·15 ± 0·03°(Z= 4). The intensity data were collected on a Picker automatic diffractometer (Cu-K_α radiation) and the structure was solved by iterative application of Sayre's equation. All hydrogen atoms were located by difference synthesis. Least-squares refinement of atomic positions, hydrogen isotropic thermal parameters, and anisotropic thermal parameters for all other atoms converged at a final R= 5·7% for 1340 reflections above background.

The condensed ring system is found to be planar, while the cyclohexane ring takes a chair conformation with the azo-group equatorial and the condensed ring axial. The methyl and cyclohexyl substituents of the azo-group are trans. The molecule contains a localized CN double bond of length 1·243 Å, and three C–N single bonds with distances 1·461, 1·472, and 1·494 Å. The oxygen atom forms bonds of 1·445 Å to the saturated carbon atom and 1·386 Å to the unsaturated carbon. The length of the azo NN bond is 1·230 Å. The carbon–chlorine bond distance, 1·720 Å, is normal. Carbon–carbon bonds in the benzene ring vary from 1·355 to 1·424 Å while the bond angles range from 118·8 to 122·4°; these variations may indicate some minor distortion.