Vibrationally Resolved Absorption and Luminescence Spectra of Mass-Selected Free-Base and Zinc Phthalocyanine Radical Cations Isolated in Solid Ne.

We report the first vibrationally well-resolved absorption and laser-induced fluorescence spectra of the radical cations of free-base phthalocyanine (H2Pc+) and zinc phthalocyanine (ZnPc+) isolated in 5 K neon matrices and compare them to the spectral properties of the corresponding neutrals. The samples were generated by low-energy deposition of the mass-selected ions. The spectra are also discussed in terms of time-dependent density functional theory calculations and compared with recently reported scanning tunneling microscopy-induced single-molecule luminescence of the same species adsorbed on NaCl-covered Au(111) or Ag(111) single crystal supports.