Upon photoexcitation, a CO molecule dissociates from FeTCPP and organized anisotropic movements occur within the instrument response function (<200 fs). The organized anisotropic movements include coherent oscillation (I osc ) and the formation of a transient structure (I tr ). In I osc , the Fe and Zr atoms oscillate with a period of 5.55 ps. The Fe atom oscillates in a doming–undoming manner along the direction perpendicular to the plane formed by TCPP, while the Zr atoms oscillate along the d axis connecting two different occupation sites of a Zr atom due to positional disorder. In I tr , the doming of the porphyrin (blue arrow) and the disordering of the Zr atoms (magenta arrows) in the Zr 6 node are enhanced. I osc and I tr decay with time constants of 2.68 and 47.1 ps, respectively. The structure of the ground state (faint lines) is superimposed on the schematic images of I osc and I tr for comparison. In addition to the organized anisotropic movements, the vibrationally hot structure (I hot ) with isotropic structural movement is formed with time constants of 1.143 and 11.32 ps. In I hot , Zr, Fe and the CO ligand all exhibit broader electron distributions (orange shading) than in the ground state due to vibrational excitation. Zr, Fe and the CO ligand are shown in green, orange and grey, respectively. The TCPP ligand connecting the Zr and Fe sites is represented by a wavy line. The two disordered positions of a Zr atom in the ground state and each structural species are represented in cyan. h represents the photon energy, where h is Planck’s constant and is the frequency of the photon.
