Table 1.

Calculated free energies for loss of an axial Met ligand [constrained at different Cu–S(Met) distances] from an oxidized copper site at room temperature

Model, Å*	ΔE†	ΔH‡	ΔS	TΔS	ΔG
2.4§	10.4 (6.8)	9.1 (5.4)	39 (42)	11.7 (12.5)	−2.6 (7.1)
2.8¶	8.9 (5.2)	7.7	35	10.4	−2.7
4.0¶	6.2 (1.9)	5.5	20	6.0	−0.2

*Oxidized Cu site model: [Cu(Im)₂(SCH₃)(S(CH₃)₂)]⁺.

^†Total electronic energy change for loss of Met ligand.

^‡ΔE with zero-point and thermal corrections included: H = E_electronic + E_ZPE + E_vib + E_rot + E_trans + RT. ZPE = zero point energy. The results of PCM calculations are shown in the parentheses. ΔE, ΔH, TΔS, and ΔG are in kcal/mol, and ΔS is in cal/mol·K.

^§The d_{Cu–S(thioether)} distance is obtained from full geometry optimization.

^¶The d_{Cu–S(thioether)} distance is constrained as indicated.