Table 3.

Thermodynamic parameters for the switching between the closed and semi-open isomers of complexes 7b–f and 8b–f, respectively, at 298 K.^a,^b

Complexes	Solvent Ratio (CD2Cl2:THF-d8)	Keq (M−1)	ΔG° (kcal/mol)	ΔH° (kcal/mol)	TΔS° (kcal/mol)
7b,8b	20:80	3×103	−4.7	8.1	13
	10:90	1.6×104	−5.7	7.2	13
7c,8c	20:80	1×103	−4.1	8.0	12
	10:90	1.2×104	−5.6	6.7	12
7d,8d	20:80	2×103	−4.5	7.5	12
	10:90	3×103	−4.7	6.2	11
7e,8e	20:80	2.7×106	−8.8	7.2	16
	10:90	4.7×104	−6.4	5.9	12
7f,8f	20:80	2.8×106	−8.8	6.4	15
	10:90	1.7×104	−5.8	5.9	12

^aEnthalpy and entropy values were obtained by neglecting the solvent heat capacity –ΔCp°.¹⁴

^bThermodynamic parameters were extrapolated from van’t Hoff plots (see Supporting Information).