The crystal structures of p-ido-N-(p-cyanobenzylidene)aniline and p-cyano-N-(p-iodobenzylidene)aniline

The crystal structures of the isomers NC - C6H4 - CH = N - C6H4 - I (CN/I) and I-C6H4-CH=N-C6H4-CN (I/CN) have been determined. CN/I is triclinic, spa ce group P (1) over bar with a = 7.504(3), b = 11.936(4), c = 7.304(2) Angs trom, alpha = 93.09(2), beta = 110.49(2), gamma = 99.04(2)degrees, V = 601. 1(3) Angstrom(3), Z = 2, and D-x = 1.835(1) g cm(-3). I/CN is triclinic, sp ace group P (1) over bar with a = 8.634(3), b = 10.560(4), c = 7.180(2) Ang strom, alpha = 94.73(2), beta = 111.13(2), gamma = 91.48(2)degrees, V = 606 .8(2) Angstrom(3), Z = 2, and D-x = 1.818(1)g cm(-3). In both compounds the re are chains of molecules held together by CN ... I interactions, with N . .. I distances of 3.15 and 3.26 Angstrom, respectively. The chains form sim ilar two-dimensional sheets, which, however, stack differently in the two c ompounds.