title: Anomalous slowing down of the vibrational relaxation of liquid water upon nanoscale confinement.
abstract: We study the vibrational dynamics of nanodroplets of liquid water with femtosecond two-color midinfrared pump-probe spectroscopy. For the smallest nanodroplet, containing 10-15 water molecules, the lifetime T1 of the O-H stretch vibrations is equal to 0.85+/-0.1 ps, which is more than 3 times as long as in bulk liquid water. We find that the truncation of the hydrogen-bond network of water leads to a dramatic change of the relaxation mechanism.
authors.affiliation: FOM Institute for Atomic and Molecular Physics [AMOLF], Kruislaan 407 Amsterdam, The Netherlands.
authors.forename: Adriaan M
authors.initials: AM
authors.lastname: Dokter
authors.forename: Sander
authors.initials: S
authors.lastname: Woutersen
authors.forename: Huib J
authors.initials: HJ
authors.lastname: Bakker