1 Supplementary material: 1,4-Dialkyl-1,4-diazabutadienes, their reactions with aluminum and indium halides. H. Rojas-Sáenz, G. V. Suárez-Moreno, I. Ramos-García, A. M. Duarte-Hernández, E. Mijangos, A. Peña-Hueso, R. Contreras and A. Flores-Parra* Department of Chemistry, Cinvestav, AP 14-740, CP 07000, México DF. e-mail: aflores@cinvestav.mx INDEX: S1 Discussion of the X-ray diffraction analyses of (R) 1-chloro-butan-2-amine hydrochloride. S2 Macromolecular helix arrangement in the crystal of compound 2. S3 Theoretical conformational analysis of 1,4-dialkyl-1,4-diazabutadienes 1-4. S4 X-Ray diffraction structure of compound 10. S5 Cell packing representation of compound 14 with [I 3 ] - as anion. S6 Optimized structures of compounds: 5, 17, 18, 20-22. S7 Representation of the electrostatic potentials of the indium compounds 16-18 and of the ligand 3 coordinated to one and two InCl 3 molecules. Electronic Supplementary Material (ESI) for New Journal of Chemistry This journal is © The Royal Society of Chemistry and The Centre National de la Recherche Scientifique 2013