Supramolecular gels from alkylated benzimidazolone derivatives

In this work, seven alkylated benzimidazolone (BZI) derivatives were synthesized with different size and shaped hydrocarbon tail-groups connected to the primary H-bonding BZI head-group via either an amide or urea secondary H-bonding linker group. The gelation behavior of these compounds was screened in up to 53 organic liquids with different properties and examined using Hansen solubility parameters (HSPs) in order to identify successful gelators and structural attributes responsible for gelation. Successful gelators possessed an amide linker and a branched hydrocarbon tail-group. The size, shape (degree of branching) and hydrophobicity of the tail-group significantly influenced the gelator ability, rheological properties and network morphology. Spectroscopic, powder x-ray diffraction, and molecular modelling studies were also carried out to provide insight into the self-assembly driving forces and supramolecular structure of gels with low polarity liquids. Finally, cytotoxicity studies suggested that the alkylamido BZI gelators biocompatible and could be used for biomedical applications and may even have some therapeutic properties of their own.