Ultrafast vibrational dynamics of interfacial water

Abstract

We report investigations on the ultrafast vibrational dynamics of water molecules at model biological interfaces and the neat water/air interface, using a newly developed surfacespecific 4th-order femtosecond infrared pump-probe spectroscopic technique. The vibrational relaxation rates and mechanisms depend strongly on the nature of the interface. Whereas water at the neat water/air interface exchanges vibrational energy rapidly with the bulk, the water molecules at model biological interfaces are energetically decoupled from the bulk.