Structural sensitivity of peptoid-based low molecular mass organogelator

A new class of peptoid-based low molecular mass organogelators was prepared by the aza-Michael addition reaction. The gelation was observed only for tert-butyl group substituted peptoid in chlorinated solvents including chloroform, 1,2-dichloroethane, and 1,2-dichlorobenzene. Interestingly, the peptoids with methyl, ethyl, n-propyl, n-butyl, and isobutyl groups did not exhibit gelation, indicating unique structural sensitivity of organogelation. The compound reported here is one of the simplest low molecular mass organogelators prepared so far. The physical properties, spectral data, and ab initio calculation suggest that nanofibrous morphology developed through the intermolecular hydrogen bonding of peptoid molecules plays a crucial role in organogelation. This study provides insights in designing various peptoid-based small molecule organogelators, and suggests that a minute structural difference should affect the formation of organogels significantly.