Matrix isolation spectroscopy and molecular dynamics simulations for 2,7,12,17-tetra-tert-butylporphycene in argon and xenon

Journal Article · Sun Oct 07 04:00:00 EDT 2007 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.2774983· OSTI ID:21024246

Kyrychenko, Alexander; Gawinkowski, Sylwester; Urbanska, Natalia; Pietraszkiewicz, Marek; Waluk, Jacek ^[1]

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1. Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw (Poland)

Electronic absorption spectra of 2,7,12,17-tetra-tert-butylporphycene (TTPC) have been recorded in low-temperature argon and xenon matrices for various deposition conditions. In the region of the S{sub 0}-S{sub 1} electronic transition, the spectra of TTPC in argon reveal a rich site structure, characterized by a series of more than 30 absorption peaks. Studies of the temperature dependence of the electronic spectra in solid argon demonstrated remarkable spectral changes, resulting in the broadening of all bands with increasing temperature. These temperature-induced spectral changes are, to a large degree, reversible, so lowering of temperature is accompanied by the recovery of the original fine-line spectrum. The absorption spectra in xenon reveal broad bands, on which a rich pattern of lines becomes superimposed at low temperatures. Trapping site distribution and the structure of the microenvironment around the TTPC chromophore, embedded in argon and xenon hosts, have been analyzed using molecular dynamics (MD) simulations. The MD results show that the trapping of TTPC in rare-gas solids is influenced by favorable embedding of the bulky tert-butyl groups inside the matrix cage. The crucial role of the tert-butyl groups for the thermodynamics and kinetics of matrix deposition is demonstrated by comparing the results with those obtained for the parent, unsubstituted porphycene.

• OSTI ID: 21024246
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 13 Vol. 127; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ABSORPTION SPECTRA
ARGON
DEPOSITION
KINETICS
MATRIX ISOLATION
MOLECULAR DYNAMICS METHOD
ORGANIC COMPOUNDS
SIMULATION
SPECTROSCOPY
TEMPERATURE DEPENDENCE
THERMODYNAMICS
XENON