ADSORPTION OF ORGANIC-MOLECULES ON LARGE WATER CLUSTERS

The sticking efficiencies for a range of organic molecules (methanal, propan-2-ol, acetone, acetaldehydel formic acid, benzene, trimethylami ne, and ethene) onto large water clusters, containing several hundred water molecules, have been determined using a supersonic molecular bea m expansion to generate the water clusters and the pickup technique to deposit the organic molecule onto the cluster. It is believed that th e organic molecule remains adsorbed onto the surface of the cluster an d is not incorporated into the bulk of the cluster. The relative stick ing coefficients are found to correlate with the magnitudes of the int eraction energy for the organic molecule and water. It is suggested th at the higher sticking efficiencies (e.g., for formic acid and acetald ehyde) may result from the molecules forming more than one hydrogen bo nd to the water cluster.