Knowledge Bank

Recent tunable far-infrared laser spectroscopic studies of water clusters have been carried out as a continuation of our approach to investigating intermolecular forces and internal tunneling dynamics of chemically and biologically important systems. Following the first report of FIR VRT transitions of $(D2O)2$ and $(D2O)3$ by Pugliano $etal.,1.2$ we have measured new intermolecular rovibrational bands for $(H2O)2.(D2O)2$. and $(D2O)3$. Preliminary analysis shows that the first observed band for $(H2O)2$ arises from $Ka=0\leftarrow 1$ transitions around $103cm-1$, the three newly observed VRT $Ka=0\leftarrow 0$ subbands for $(D2O)2$ around $103cm-1$ correspond to a second intermolecular vibrational mode. A second vibrational mode of $(D2O)3$ has also been observed at $96cm-1$.