Theoretical study on microhydration of : On the number of water molecules necessary to stabilize the dianion

Microhydration of SeO 4 2 - · n H 2 O (n = 1–5) clusters are reported at B3LYP/Aug-cc-pvtz level of theory. Lower size hydrated clusters are stabilized by only double-hydrogen-bonding arrangements and the most stable conformer for higher size cluster (n > 3) contains a cyclic water ring. It is observed that at least one water molecule is necessary to stabilize the dianion in the gas phase against spontaneous electron loss. The microscopic theory based expression provides a route to predict the instability of bare SeO 4 2 - and to obtain the VDE for a wide range of cluster sizes including the bulk from the knowledge of the same for a few stable hydrated clusters.