Influences of n (2-5) water molecules on the proton transfer in hydrated glycine complexes

N (here n is from 2 to 5) water molecules hydrated glycine complexes have been studied by MP2/6-31++G**//B3LYP/6-31++G** method and influences of number increasing of water molecules on the proton transfer have been investigated. Proton transfers either by direct mode or by water-bridged mode, and in the water-bridged mode the number of water molecules in bridge can be from 1 to n. Number increasing of water molecules helps the zwitterionic glycine forms to be more stable, and helps the proton to transfer by lowering the transferring energy barrier.

Highlights► Proton can transfer via a water-bridge chained by 1-5 water molecules. ► Number increasing of water molecules is thermodynamically in favor of zwitterionic forms' relative stability. ► Number increasing of water molecules is kinetically in favor of proton transfer for neutral form to be zwitterionic form.