Electronic states of neutral and cationic bis(benzene) titaniumand vanadium sandwich complexes studied by pulsed field ionization electron spectroscopy

Ti- and V - bz 2 ( bz = C 6 H 6 ) sandwich complexes have been prepared in a laser-ablation cluster beam source and studied by pulsed field ionization-zero electron kinetic energy photoelectron spectroscopy and theoretical calculations. The ground electronic states of the neutral Ti- and V - bz 2 complexes are determined to be A 1 g 1 and A 1 g 2 , and their ionization energies are measured to be 5.732 ± 0.001 and 5.784 ± 0.002 eV , respectively. These neutral complexes have η 6 binding and are in an eclipsed D 6 h configuration with flat benzene rings. Ionization of the A 1 g 1 and A 1 g 2 neutral states of Ti- and V - bz 2 yields the B 1 g 2 and B 1 g 3 ion states, respectively, in a D 2 h point group with slightly puckered benzene rings. In addition, the binding and structures of these two complexes are compared with other first-row transition metal bis(benzene) sandwiches.