Multiply charged energetic metal ion emissions from dinuclear metal complex exposed to intense femtosecond laser fields

Abstract

Coulomb explosion of nonmetal ions emerged from a variety of molecules has been studied and utilized for the determination of molecular structure and reaction dynamics. In contrast, Coulomb explosion of metal ions, particularly the large Coulombic interactions are expected, has not yet been explored. In this study, the angular distributions of Mnx+ (x = 1–5), Cy+ (y = 1–4), and Oz+ (z = 1–3) emerged from dimanganese decacarbonyl, in which two metal atoms are sandwiched by axial ligands, exposed to intense femtosecond laser fields (1 × 1014–3 × 1015 W cm−2) are investigated. Manganese ions are produced at relatively low laser intensity compared with other transition metal ions with the same charge number but emerged from mononuclear complexes such as metallocenes and metal hexacarbonyls. The kinetic energies of Mn4+ and Mn5+ are described by the simple Coulomb repulsion model of manganese dimer ion. Fairly high kinetic energy of oxygen and carbon ions compared with those emerged from metal hexacarbonyls strongly suggests that atomic ions originating in ligands are repelled by manganese ions at the moment of Coulomb explosion. The use of dinuclear metal complex is advantageous in the production of multiply charged metal ions accompanying high kinetic energy since two manganese ions are in close confinement due to the repulsions with axial ligand (atomic) ions.