In this work, we study the binary complexes of water with formaldehyde, ace
taldehyde and acetone using density functional theory. The highest level of
theory we used was the B3LYP/6-311++G(3df,3pd). At this level of theory, t
he computed binding energies were 2.6 kcal mole(-1) for water-formaldehyde,
3.5 kcal mole(-1) for water-acetaldehyde and 3.9 kcal mole(-1) for water-a
cetone. We also compute vibrational and rotational frequencies and compare
the former to matrix isolation experiments when possible. Equilibrium const
ants for the formation of these complexes are calculated from the data, as
well as rate constants for the dissociation of the complex. Some speculatio
n can be made using this data as to the effect these complexes may have on
atmospheric chemistry. (C) 2000 Elsevier Science Ltd. All rights reserved.