Spectroscopy and fragmentation of undercoordinated bromoiridates

We report gas-phase electronic photodissociation spectra of the undercoordinated bromoiridate complexes IrBr(4)(-) and IrBr(5)(-) at photon energies from 1 to 5.6 eV. Both ions have open-shell ground states with low-symmetry structures. The fragmentation is characterized by thresholds for the loss of one Br atom for IrBr(4)(-) and one or two Br atoms for IrBr(5)(-). The experimental spectra consist of ligand-to-metal charge transfer transitions and reveal a large density of electronic states that can be recovered by time-dependent density functional theory.