Publication
Title
Electronic states of anthanthrene : linear and magnetic circular dichroism, polarized fluorescence, and quantum chemical calculations
Author
Abstract
The pericondensed benzenoid hydrocarbon anthanthrene (dibenzo[def,mno{]chrysene, dibenzo[}cd,jk{]pyrene) was investigated by UV-VIS and IR linear dichroism (LD) spectroscopy in stretched polyethylene, by UV-VIS magnetic circular dichroism (MCD) spectroscopy, and by fluorescence polarization anisotropy measurements. The combined results led to a detailed experimental characterization of electronic transitions in the near-UV and visible regions, with determination of polarization directions. In particular, the results allowed an unambiguous assignment of the weak L} b { transition (corresponding to Clar's }α {-band), in spite of overlap with the much stronger L} a { transition (Clar's} p{-band). This assignment, which is at variance with a previous suggestion, was supported by a study of solvent and temperature shifts. The experimental results were compared with theoretical predictions using the LCOAO procedure. Excellent agreement with observed transitions was obtained, including transition moment directions and MCD signs. The theoretical analysis revealed a significant breakdown of the alternant pairing symmetry for anthanthrene, corresponding to Δ HOMO > Δ LUMO. Similar to benzo[}a{]pyrene, anthanthrene can be classified as a positive-hard MCD chromophore in Michl's terminology.
Language
English
Source (journal)
Polycyclic aromatic compounds. - Place of publication unknown
Publication
Place of publication unknown : 2005
ISSN
1040-6638
Volume/pages
25:1(2005), p. 23-45
ISI
000226981500003
Full text (Publishers DOI)
UAntwerpen
Faculty/Department
Publication type
Subject
External links
Web of Science
Record
Identification
Creation 20.12.2013
Last edited 10.04.2017