Comprehensive study on the solvation of mono- and divalent metal cations: Li+, Na+, K+, Be2+, Mg2+ and Ca2+.
Hydration of mono- and divalent metal ions (Li(+), Na(+), K(+), Be(2+), Mg(2+) and Ca(2+)) has been studied using the DFT (B3LYP), second-order Møller-Plesset (MP2) and CCSD(T) perturbation theory as well as the G3 quantum chemical methods. Double-zeta and triple-zeta basis sets containing both (multiple) polarization and diffuse functions were applied. Total and sequential binding energies are evaluated for all metal-water clusters containing 1-6 water molecules. Total binding energies predicted at lower levels of theory are compared with those from the high level G3 calculations, whereas the sequential binding energies are compared with available experimental values. An increase in the quality of the basis set from double-zeta to triple-zeta has a significant effect on the sequential binding energies, irrespective of the geometries used. Within the same group (I or II), the sequential binding energy predictions at the MP2 and B3LYP vary appreciably. We noticed that, for each addition of a water molecule, the change of the M-O distance in metal-water clusters is higher at the B3LYP than at the MP2 level. The charge of the metal ion decreases monotonically as the number of water molecules increase in the complex.
Molecular Modeling Group, Organic Chemical Sciences, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 007, Andhra Pradesh, India.
J Srinivasa
JS
Rao
T C
TC
Dinadayalane
Jerzy
J
Leszczynski
G Narahari
GN
Sastry
D001608:Beryllium / Q000737:chemistry; D002118:Calcium / Q000737:chemistry; D002413:Cations, Divalent / Q000737:chemistry*; D002414:Cations, Monovalent / Q000737:chemistry*; D007700:Kinetics; D008094:Lithium / Q000737:chemistry; D008274:Magnesium / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D011188:Potassium / Q000737:chemistry; D012964:Sodium / Q000737:chemistry; D013816:Thermodynamics
D002413:Cations, Divalent; D002414:Cations, Monovalent; D008670:Metals; D008094:Lithium; D012964:Sodium; D008274:Magnesium; D001608:Beryllium; D011188:Potassium; D002118:Calcium