Computational investigation on interaction of magnesium ion and cyclen

Abstract

B3LYP/6–311++G(d,p)-optimized structures of cyclen (1,4,7,10– tetraazacyclododecane) complex with magnesium ion (Mg/cyclen complex) and its interaction complexes with water, chloride ion and nitrate ions were obtained. Each of all complexes are composed of six conformations. Relative energies and formation energies for all studied complexes were calculated. The Mg/cyclen complex with high symmetry interacting with two water molecules with chloride ion lead to the MD (molecular dynamics) simulation of which comprises 500 water molecules, one cyclen, one magnesium ion and two chloride ions compared with the same simulation condition without cyclen ligand. Radial distribution functions of atoms of waters with magnesium and chloride ions were computed and analyzed. Two water molecules solvation with Mg²⁺ ion of the Mg/cyclen complex at above and below Mg²⁺ ion along its principal axis. Chloride ion solvated with six water molecules was found and distorted octahedral as the possible solvation structure was expected.