A butterfly like motion as a clue to the photophysics of thioxanthone
2006 (English)In: Journal of Photochemistry and Photobiology A: Chemistry, ISSN 1010-6030, Vol. 179, no 3, 298-304 p.Article in journal (Refereed) Published
A theoretical, quantum-chemical study of the thioxanthone (TX) molecule has been performed at the MP2 and CASPT2 levels of theory. Geometries, absorption energies, and transition and state properties have been investigated. Two conformers have been found very close in energy with planar (P) and non-planar (NP) structures, the latter characterized by a dihedral angle theta = 173.3 degrees representing the bend of the side benzene rings and an out-of-plane angle theta=4 degrees of the C=O bond. Large changes in the relative positions and properties of the two low-lying electronic absorption bands, pi pi* and n pi*, are computed when changing the conformation. As a consequence of the analysis of the TX absorption spectrum it is suggested that TX should be viewed as dynamically changing its conformation between the planar and the non-planar conformations. We coined such behavior as a "butterfly like motion". This dynamic view of the TX structure enables a plausible explanation of the photophysical properties observed for the system.
Place, publisher, year, edition, pages
2006. Vol. 179, no 3, 298-304 p.
thioxanthone, absorption spectrum, CASPT2, ground state structure
IdentifiersURN: urn:nbn:se:kth:diva-5085DOI: 10.1016/j.jphotochem.2005.08.033ISI: 000236722300009ScopusID: 2-s2.0-33644857241OAI: oai:DiVA.org:kth-5085DiVA: diva2:7840
Tidigare titel: A butterfly
effect as a clue to the unique photophysics of thioxanthone
Uppdaterad från submitted till published: 20101011.
QC 201010112005-04-282005-04-282010-10-11Bibliographically approved