title: Vibrations and hydrogen bonding in porphycene.
abstract: Combined use of IR, Raman, neutron scattering and fluorescence measurements for porphycene isolated in helium nanodroplets, supersonic jet and cryogenic matrices, as well as for solid and liquid solutions, resulted in the assignments of almost all of 108 fundamental vibrations. The puzzling feature of porphycene is the apparent lack of the N-H stretching band in the IR spectrum, predicted to be the strongest of all bands by standard harmonic calculations. Theoretical modeling of the IR spectra, based on ab initio molecular dynamics simulations, reveals that the N-H stretching mode should appear as an extremely broad band in the 2250-3000 cm(-1) region. Coupling of the N-H stretching vibration to other modes is discussed in the context of multidimensional character of intramolecular double hydrogen transfer in porphycene. The analysis can be generalized to other strongly hydrogen-bonded systems.
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw, Poland.
authors.forename: Sylwester
authors.initials: S
authors.lastname: Gawinkowski
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Walewski
authors.forename: Alexander
authors.initials: A
authors.lastname: Vdovin
authors.forename: Alkwin
authors.initials: A
authors.lastname: Slenczka
authors.forename: Stephane
authors.initials: S
authors.lastname: Rols
authors.forename: Mark R
authors.initials: MR
authors.lastname: Johnson
authors.forename: Bogdan
authors.initials: B
authors.lastname: Lesyng
authors.forename: Jacek
authors.initials: J
authors.lastname: Waluk
mesh_terms: D006860:Hydrogen Bonding; D015394:Molecular Structure; D011166:Porphyrins / Q000737:chemistry*; D011789:Quantum Theory; D014732:Vibration
chemical_list: D011166:Porphyrins; C051407:porphycene