Molecular assemblies of diazafluorenone Schiff-base amphiphiles. III.13C NMR investigations of reversed micelles in deuteriochloroform

Abstract

13C NMR investigations of a nonionic amphiphile of diazafluorenone Schiff base with an alkyl chain length of C14 (DAFSB-C14) in deuteriochloroform (CDCl3) indicate the formation of small reversed micellar aggregates. From the observed13C chemical shifts as functions of amphiphile concentration, the critical micelle concentration (cmc), aggregation numbers (n), and equilibrium constants for micelle formation (K) have been obtained. The values of chemical shifts have shown that DAFSB-C14 is aggregated using the head group. The π-π interactions between the rigid head groups, which constitute the main attractive force for aggregation, lead to the formation of relatively small aggregates. A plausible aggregation model is discussed.