THE CALCULATION OF BOND-DISSOCIATION ENERGIES OF TRANSITION-METAL COMPLEXES USING ISOSTRUCTURAL REACTIONS

The metal-ligand bond dissociation energies (CO)(n)M-L are theoretically predicted at the HF, MP2 and CCSD(T) levels of theory using effective core potentials for the metals for M = Cr, Mo, W, Ni, Pd, Pt and for L = CO, NO+, CN-, NC-, CS, SiO, N-2. The bond energies at the HF level are too low and the MP2 values are too high, while the CCSD(T) results are in good agreement with experimental data. The bond energies at MP2 show the same trend as the CCSD(T) values and may therefore be used for the prediction of relative bond dissociation energies. The absolute values for the bond energies calculated at MP2 are significantly improved when they are corrected using the energies of isostructural reactions M(CO)(n) + L--> M(CO)(n-1)L + CO.