The structure of molecular compounds. Part XIII. Crystal structure of the molecular compound of cis-dicyanotetra(methyl isocyanide)iron(II) with four molecular of chloroform

Abstract

A crystal structure analysis of Fe^II(CN)₂(MeNC)₄·4CHCl₃ has been made. In the crystals, which contain at least 60% by volume of chloroform, molecules of the dicyano-complex are arranged so as to form layers within which the terminal atoms of the ligand arms are at normal van der Waals contact distance. As a result of these contacts the nearly linear and rigid arms come into position which leave a set of connected cavities in the layer. Half of the chloroform molecules take up positions so that they fill space in these cavities; one chlorine atom of each molecule projects outwards so that both surfaces of the layer include chlorine atoms of this type. These comlexe layers of composition Fe(CN)₂(MeNC₃)₄·2CHCl₃ alternate with parallel layers consisting entirely of the remaining chloroform, which makes a close contact through its hydrogen atom to the nitrogen of a cyanide group. The chloroform molecules in these layers show much greater thermal motion than those partly trapped in the cavities. Interactions of the component molecules are discussed.