Nuclear magnetic shielding of the Cd-113(II) ion in aqua solution : A combined molecular dynamics/density functional theory study

• We present a combined molecular dynamics simulation and density functional theory investigation of the nuclear magnetic shielding constant of the Cd-113(II) ion solvated in aqueous solution. Molecular dynamics simulations are carried out for the cadmium-water system in order to produce instantaneous geometries for subsequent determination of the nuclear magnetic shielding constant at the density functional theory level. The nuclear magnetic shielding constant is computed using a perturbation theory formalism, which includes nonrelativistic and leading order relativistic contributions to the nuclear magnetic Shielding tensor. Although the NMR shielding constant varies significantly with respect to simulation time, the value averaged over increasing number of snapshots remains almost constant. The paramagnetic nonrelativistic contribution is found to be most sensitive to dynamical changes in the system and is mainly responsible for the thermal and solvent effects in solution. The relativistic correction features very little sensitivity to the chemical environment, and can be disregarded in theoretical calculations when a Cd complex is used as reference compound in Cd-113 NMR experiments, due to the mutual cancelation between individual relativistic corrections.

Ämnesord

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

Nyckelord

quadrupole coupling-constant

initio scf calculations

chemical-shift

tensor

particle mesh ewald

single-crystal

liquid water

cadmium

compounds

solid-state

resonance spectroscopy

acetate dihydrate

Chemistry

Biochemistry

NATURAL SCIENCES

Biochemistry

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