Formamide in Reverse Micelles: Restricted Environment Effects on Molecular Motion

Novel Aerosol OT (AOT) reverse micelles solubilizing formamide rather than water have been created and studied. In contrast to water sequestered in the interior of AOT reverse micelles, the vibrational spectra indicate that the intramicellar formamide retains a large degree of hydrogen bonding character and its structure appears significantly less perturbed by the restricted environment than water. However, solvation dynamics measurements show that the intramicellar formamide is nearly completely immobilized, a dramatic departure from bulk solvation dynamics. These results show that structural aspects derived from the characteristic vibrational motion does not necessarily provide insight into other dynamical solvent behavior.