Fig 5.

Thermodynamics of switching in motor rotation. (a) Schematic free-energy diagram showing the equilibrium relation between CCW and CW states before (dashed line) and after (solid line) application of pressure. (b) Thermodynamic parameters. (Top) Free-energy difference at 0.1 MPa; ΔG₀. The standard enthalpy and entropy were −310 kJ mol⁻¹ and −1.1 kJ K⁻¹ mol⁻¹, respectively. (Bottom) Pressure dependence parameter (reaction volume; ΔV). The plots could be fitted by α · (273 + T) + β, where α is equal to 1.1 cm³ mol⁻¹ K⁻¹ and β is equal to −510 cm³ mol⁻¹. (c) Pressure-temperature phase diagram. The value of ΔG is represented by gray curves at intervals of 10 kJ mol⁻¹. The blue, green, and red regions correspond to CW biases of <0.1, 0.1 to 0.9, and >0.9, respectively. The diagram was constructed using α and β, the standard enthalpy and entropy in panel b.