title: Evidence for Dominant Role of Tunneling in Condensed Phases and at High Temperatures: Double Hydrogen Transfer in Porphycenes.
abstract: Investigation of the double hydrogen transfer in porphycene, its 2,7,12,17-tetra-tert-butyl derivative, and their N-deuterated isotopologues revealed the dominant role of tunneling, even at room temperature in condensed phase. Ultrafast optical spectroscopy with polarized light employed in a wide range of temperatures allowed the identification and evaluation of contributions of two tunneling modes: vibrational ground-state tunneling, occurring from the zero vibrational level, and vibrationally activated, via a large amplitude, low-frequency mode. Good correspondence was found between the rates of incoherent tunneling occurring in condensed phase and the values estimated on the basis of tunneling splittings observed in molecules isolated in supersonic jets or helium nanodroplets. The results provide solid experimental insight into widely proposed quantum facets of ubiquitous hydrogen-transfer phenomena.
authors.affiliation: Institute of Experimental Physics, Faculty of Physics, University of Warsaw , Pasteura 5, 02-093 Warsaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Ciąćka
authors.affiliation: Institute of Experimental Physics, Faculty of Physics, University of Warsaw , Pasteura 5, 02-093 Warsaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Fita
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences , Kasprzaka 44/52, 01-224 Warsaw, Poland.|Faculty of Mathematics and Natural Sciences, College of Science, Cardinal Stefan Wyszyński University , Dewajtis 5, 01-815 Warsaw, Poland.
authors.forename: Arkadiusz
authors.initials: A
authors.lastname: Listkowski
authors.affiliation: Institute of Experimental Physics, Faculty of Physics, University of Warsaw , Pasteura 5, 02-093 Warsaw, Poland.
authors.forename: Czesław
authors.initials: C
authors.lastname: Radzewicz
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences , Kasprzaka 44/52, 01-224 Warsaw, Poland.|Faculty of Mathematics and Natural Sciences, College of Science, Cardinal Stefan Wyszyński University , Dewajtis 5, 01-815 Warsaw, Poland.
authors.forename: Jacek
authors.initials: J
authors.lastname: Waluk