Electronic Spectra of Cryogenically Cooled Na -Pyrene and K -Pyrene Complexes

Abstract

The Na+-pyrene and K+-pyrene complexes are investigated using two-color resonance enhanced photodissociation action spectroscopy in a cryogenic ion trap and through complementary density functional theory calculations. Both complexes are predicted to have π-bound structures in which the metal cation lies above the plane of the pyrene molecule, with calculated binding energies of 10570 and 8150 cm–1, respectively. Electronic spectra of Na+-pyrene and K+-pyrene over the 26,000–33,000 cm–1range exhibit S1(B2u) ← S0(Ag) and S2(B1u) ← S0(Ag) band systems associated with excitation of the pyrene chromophore. The S1(B2u) ← S0(Ag) band systems of Na+-pyrene and K+-pyrene are dominated by progression..