Fig. 4

Metal K-edge extended X-ray absorption fine structure (R space plots). a Ni-SAC, b Mn-SAC, c Fe-SAC, d Co-SAC, e Cr-SAC, f Cu-SAC, g Zn-SAC, h Ru-SAC, and i Pt-SAC. In all the M-SACs, the metal atoms existed as isolated M²⁺ centers in a MN₄ coordination environment