Fig. 3: Characterization of the crystalline solids of EuTTA and its radical-containing derivatives.

a Powder X-ray diffraction patterns of EuTTA, EuTTA-230, and EuTTA-350. b Solid-state EPR spectra of EuTTA and EuTTA-350 at 300 K. c The XPS spectra of Eu 3d of EuTTA and EuTTA-350. d Plots of \({{\chi }}_{{{{{{\boldsymbol{M}}}}}}}{{{{{\boldsymbol{T}}}}}}\) versus T for EuTTA, EuTTA-230, and EuTTA-350 at 1000 Oe field. e Spin densities distribution of the triplet biradical bis(dithiole) with an isosurface value of 0.02 au. and calculated SNOs of independent spins (red area stands for negative value and green area for positive value).