Abstract: Clusters and their fragments contain up to 12 acetone molecules, produced by supersonic expansion jet, are observed in the time of flight mass spectrum under 355 nm laser irradiation. The calculations using density functional theory give structures and the energies of the ground state acetone clusters for n =2-5. The results show that a near perpendicular structure is steady for 2 acetone cluster, while a circle structure is more steady for the clusters contain 3 to 5 acetone molecules.

Key words: Acetone, Cluster, Multiphoton ionization/dissociation, Density functional theory method