Laser spectroscopy of porphycene derivatives: a search for proton tunneling in 2,7,12,17-tetra-tert-butylporphycene

We report on laser induced fluorescence (LIF) excitation and UV/UV fluorescence depletion spectra of 2,7,12,17-tetra-tert-butylporphycene (TTPC) in supersonic expansion. The origin of TTPC consists of two bands, separated by 2.4 cm−1. Independent depletion, as well as the different shapes, widths, influence on ND/NH isotope exchange suggest the peculiar nature of the doublet. The results have been described in terms of two different ground state conformers.