Fig. 6. The dependence of the CW X-band EPR spectra (left) and double-integrated EPR intensity (A) (right) on the temperature of 1·K2 (a and b) and 2·K2 (c and d) in THF. Bleaney–Bowers fits to the variable-temperature EPR data gave S–T energy gaps of 4.3 and 4.7 kJ mol⁻¹ for 1·K2 and 2·K2, respectively.