A density functional theory study applied for carbon isotope effects in the non-aqueous [Cu(CO)]+/CO system

DFT calculations were performed on the carbon isotopomers of CO and CO-complexes [Cu(NH2CH2CH2OH)3(CO)]+, [Cu(CH3OH)3(CO)]+ and results compared with (Duʹs) experimental results on the carbon isotope exchange equilibria between CO and CO–copper-complex. The gas-phase model was used even for calculating the isotope effects involving the solutes of solutions. Contributions of the extramolecular motion of the solute molecular to the RPFR are responsible for the steep slope of the lnα-vs. −1/T plot of Duʹs data, where α is the isotope separation factor which is identical to K in the present exchange system. The calculated result agrees well with (Duʹs) experiment data.