Iron monoxide photodissociation

Abstract

The photodissociation of 56FeO was studied by means of the velocity map imaging technique. A molecular beam of iron atoms and iron monoxide molecules was created using an electrical discharge with an iron electrode in a supersonic expansion of molecular oxygen. The ground state iron atom Fe( 5D 4) and FeO concentrations in the molecular beam have been estimated. The dissociation energy of the FeO X 5Δ ground electronic state was found to be D 00(FeO)=4.18±0.01 eV. The effective absorption cross section of FeO at 252.39 nm (vac), leading to the Fe( 5D 4)+O( 3P) dissociation channel, is ∼1.2×10 -18 cm 2. A (1+1) resonantly enhanced multiphoton ionization spectrum of 56FeO in the region 39 550-39 580 cm -1 with rotational structure has been observed, but not assigned. Angular distributions of Fe( 5D 4) and Fe( 5D 3) products for the channel FeO→Fe( 5D 4,3)+O( 3P) have been measured at several points in the 210-260 nm laser light wavelength region. The anisotropy parameter varies strongly with wavelength for both channels.