title: Ground and excited state double hydrogen transfer in symmetric and asymmetric potentials: comparison of 2,7,12,17-tetra-n-propylporphycene with 9-acetoxy-2,7,12,17-tetra-n-propylporphycene.
abstract: Analysis of time-resolved anisotropy of transient absorption enabled determination of room temperature ground and excited state rate constants for intramolecular double hydrogen transfer in two similar porphycenes, one of them with symmetric and the other, with asymmetric character of a double minimum potential for hydrogen motion. The perturbation preserves a quasi-symmetric minimum in S(0), but the rate decreases approximately two times. In S(1), the perturbed potential becomes strongly asymmetric, and the downhill hydrogen transfer occurs with a rate higher than that observed for a symmetrical compound.
authors.affiliation: Institute of Experimental Physics, University of Warsaw, Hoża 69, 00-681 Warsaw, Poland. Piotr.Fita@fuw.edu.pl
authors.forename: Piotr
authors.initials: P
authors.lastname: Fita
authors.forename: Piotr
authors.initials: P
authors.lastname: Garbacz
authors.forename: Michał
authors.initials: M
authors.lastname: Nejbauer
authors.forename: Czesław
authors.initials: C
authors.lastname: Radzewicz
authors.forename: Jacek
authors.initials: J
authors.lastname: Waluk
mesh_terms: D000042:Absorption; D006859:Hydrogen / Q000737:chemistry*; D015394:Molecular Structure; D011166:Porphyrins / Q000737:chemistry*; D011522:Protons; D013050:Spectrometry, Fluorescence
chemical_list: C519019:2,7,12,17-tetra-n-propylporphycene; C558611:9-acetoxy-2,7,12,17-tetra-n-propylporphycene; D011166:Porphyrins; D011522:Protons; D006859:Hydrogen