X-ray diffraction study of p-(alkoxybenzylidene)-p Mathamatical Expression toluidines C2H5O-C6H4-CH=N-C 6H4-CH3 and C4H9O-C 6H4-CH=N-C6H4-CH3

The molecular and crystal structures of two p-alkoxybenzylidene)-p′-toluidines C2H5O-C6H4-CH=N-C6H4-CH3 (1) and C4H9O-C6H4-CH=N-C6H4-CH3 (2) are determined by X-ray diffraction. Crystals 1 and 2 contain four and two crystallographically independent molecules, respectively. In 1, the geometry of the independent molecules is almost identical. In 2, the independent molecules differ in the conformation of the alkyl chain, which is disordered in one of them. An analysis of the crystal packing of 2 reveals the alternation of spacious layers formed by loosely packed aliphatic fragments of molecules and layers of closely packed aromatic fragments, which ensures the formation of the mesogenic phase in the course of melting of crystals 2. In crystal 1, loose aliphatic layers are absent.