Rydberg state mediated multiphoton ionization of (η7-C7H7)(η5-C5H5)Cr: DFT-supported experimental insights into the molecular and electronic structures of excited sandwich complexes

Abstract

The resonance-enhanced multiphoton ionization (REMPI) of a mixed sandwich complex has been achieved for the first time when exciting (η⁷-C₇H₇)(η⁵-C₅H₅)Cr via the Rydberg 4p_z state. The REMPI spectrum is indicative of unexpectedly small changes of the sandwich geometry on excitation. Time-dependent DFT calculations reveal fine effects of the ligand nature on the molecular and electronic structure variations accompanying electronic excitation. Different trends are predicted for the sandwich geometry transformations in the mixed sandwich complex and its symmetric isomer, (η⁶-C₆H₆)₂Cr, both on Rydberg excitation and ionization.