Single crystal X-ray structure analysis for two thiazolylazo indole dyes

摘要

To determine the tautomeric form of the hetarylazo indole dye 3-(5-methylthiazol-2-yldiazenyl)-2-phenyl-1H-indole(1),l-methyl-3-(thiazol-2-yldiazenyl)-2-phenyl-1H-indole(2)was synthesized as a model compound and both molecules were characterized by single crystal X-ray diffraction.(1)crystallized in the monoclinic system,space group C2/c,a= 31.064(2),b= 7.4051(5),c= 27.7138(18)A,beta= 97.617(1)°,V= 6318.9(7)A~3,Z= 8,while dye 2 crystallized in the monoclinic system,space group P2_1/ n,a= 11.4660(11),b= 9.8223(9),c= 14.2049(14)A,beta= 97.418(2)°,V= 1586.4(3)A~3,Z= 4.The asymmetric unit of 1 contains two crystallographically independent molecules,in which geometries and conformations differ slightly,while there is only one molecule in the asymmetric unit for 2.The inter-molecular N-H…N hydrogen bonds in(1)link the molecules,via parallel,infinite sheets,along the a axis and stabilize the crystal structure;in 2,there is no classical intermolecular hydrogen bond.