CHARACTERIZATION OF THE (D2O)(2) HYDROGEN-BOND-ACCEPTOR ANTISYMMETRICSTRETCH BY IR CAVITY RINGDOWN LASER-ABSORPTION SPECTROSCOPY

The IR-CRLAS technique has been used to measure the mid-infrared O-D s tretching spectrum of the fully deuterated gas-phase water dimer for t he first time. The instrumentally limited resolution of 1 GHz resolves the acceptor tunneling splittings and the rotational line manifolds. The analysis of these splittings exploits the local nature of the exci tation and yields a description of the acceptor tunneling motion that supports previous experimental and theoretical results.