Ground and excited states of naphthalene–water (naphtha–W6) clusters: a computational study

Abstract

An MP2 and DFT study of the structures of naphthalene–water hexamer clusters has been performed for both the prism and cage forms of the cluster. These have been corrected for zero-point energy and counterpoise effects and show a larger binding energy for the prism structures. These have been analysed in terms of the number and type of hydrogen-bonding interactions present. We have also performed time-dependent DFT computations of the electronic excited states with a variety of functionals. Our results show good agreement between TD-CAM-B3LYP and TD-M06-2X, and predict that the presence of the water cluster red-shifts and lowers the intensity of the primary π → π* transition. This effect is more pronounced in the prism than the cage cluster. We also calculate weaker higher energy features involving charge transfer from the naphthalene to the water cluster.