High-resolution isotope selective laser spectroscopy of Ag2 molecules

Silver dimers formed in a seeded supersonic argon beam are examined with two laser spectroscopic methods. Excitation fluorescence spectra of the A-X system excited with a narrow band cw dye laser yield accurate constants of the X 1Σg+ and the A 1Σu+ state. From isotope selective resonant two-photon ionization spectra of the B-X and the E-X system excited by a pulsed dye laser and monitored with a time-of-flight mass spectrometer, improved vibrational constants and rotational constants of the B 1Πu and the E 1Πu state are derived. Rotational constants of the C and the D state could be determined from the spectral separations between bandhead and band origin in partly rotationally resolved bands. Autoionizing Rydberg states of Ag2 are stepwise excited with two pulsed dye lasers in two resonant steps. From the convergence limits of different Rydberg series converging towards different vibrational levels v+ in the X 2Σg+ ground state of Ag2+ the rotational constants of the ion ground state and the adiabatic ionization potential IP(Ag2+)=61 747±4 cm−1 could be accurately determined.