Solvation dynamics of formamide and N,N-dimethylformamide in aerosol OT reverse micelles

The solvation dynamics of formamide and N,N-dimethylformamide in Aerosol OT reverse micelles has been investigated in this work. The solvation dynamics of formamide and N,N-dimethylformamide in the reverse micelles is more than 100 times slower than that of the pure solvents. The solvation dynamics of formamide in the reverse micelle solution depends strongly on the molar ratio between formamide and Aerosol OT (w = [polar solvent]/[Aerosol OT]), but that of N,N-dimethylformamide in the reverse micelle solution shows a tiny w dependence. We have estimated the interaction energies of the geometry-optimized clusters of a simple model of the Aerosol OT polar headgroup (CH3SO3-) and formamide or N,N-dimethylformamide by ab initio calculations (the second-order Møller-Plesset perturbation theory) to find their interactions. The interaction energies of the mimic clusters estimated by the ab initio calculations and the features of the slow solvation dynamics and w dependence in formamide and N,N-dimethylformamide reverse micelles are discussed.