Chlorobenzylidene-chloroaniline

This general rule would seem to have some exceptions, as in the case of the /V-(p-chlorobenzylidene)-p-chloroaniline (B ACL), in which the crystal imposes on the molecule a conformational symmetry which the isolated molecule does not possess [7J5],... 

Bernstein, J. and Schmidt, G. M. J. (1972). Conformational studies. Part IV. The crystal and molecular structure of the metastable form of N-(j9-Chlorobenzylidene)-p -chloroaniline, a planar anil. / Chem. Soc., Perkin Trans. 2, 951-5. [72, 227]... 

Polymorphism is ubiquitous (see, e.g.. Ref. [9-48]), and most compounds can exist in more than one crystalline form. Bernstein and co-workers [9-37] have extensively studied conformational polymorphism of various organic compounds with a variety of techniques in addition to X-ray crystallography. Among the molecules investigated were A-(p-chlorobenzylidene)-p-chloroaniline [9-3, X = Cl (I)], which exists in at least two forms, and/7-methyl-A-(/7-methylbenzyl-idene)aniline [9-3, X = CHj (II)], which exists in at least three forms. For I, a... 

Subsequently, additional studies of the effect of crystal forces on molecular conformations were reported for various methyl analogues of jV-( -chlorobenzylidene)-p-chloroaniline [33], The ah initio calculations were able to predict the relative stability of the various polymorphs, and by using a number of potential functions the authors were able to demonstrate the ruggedness of the method. Taken together, the two works demonstrate that use of partial atomic energies for the analy-... 

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