Novel isoindigo derivatives bearing long-chain N-alkyl substituents: Synthesis and self-assemble behavior

A mild, catalyst-free and simple synthesis of 1,1′-di(n-alkyl)-isoindigo via the reaction of substituted isatins with tris(diethylamino)phosphine is reported. Their self-assembly in water–DMF (50% v/v) solution was investigated. Unexpectedly, no surface activity was observed for compound 2h. Spectrophotometry and fluorimetry allowed determining critical micelle concentration (0.1 mM and 0.8 mM respectively). Aggregation numbers of 8 and sizes of aggregates were determined.