Knowledge Bank

There has been a great deal of investigation into better understanding hydrophobic interactions in liquid phase systems. However, progress in understanding the most fundamental solute-solvent interactions has been impeded by the lack of accurate potential energy surfaces for these systems. In this talk, we present the far infrared spectrum of $CH4-H2O$, as well as a proposed energy level scheme for this dimer. The experimental apparatus is a tunable far infrared laser spectrometer combined with a planar supersonic jet expansion. Over 200 lines have been observed, of which 110 lines have been assigned to nine different vibration-rotation bands at $-19cm-1,$ all of which, we propose are associated with the $\sigma (101)-\Pi (110)$ transition in the water $subunit1$. Exact vibrational assignments have yet to be determined. In addition, preliminary results indicate that the $CH4-H2O$ is considerably more strongly bound than $Ar-H2O$ (D.E. $\Sigma (101)---137cm-12$)