Campus Units
Chemistry
Document Type
Article
Publication Version
Published Version
Publication Date
10-2010
Journal or Book Title
Journal of the American Chemical Society
Volume
132
Issue
45
First Page
16247
Last Page
16255
DOI
10.1021/ja1075162
Abstract
Benzannulation of aromatic molecules is often used to red-shift absorption and emission bands of organic and inorganic, molecular, and polymeric materials; however, in some cases, either red or blue shifts are observed, depending on the site of benzannulation. A series of five platinum(II) complexes of the form (N∧N∧N)PtCl are reported here that illustrate this phenomenon, where N∧N∧N represents the tridentate monoanionic ligands 2,5-bis(2-pyridylimino)3,4-diethylpyrrolate (1), 1,3-bis(2-pyridylimino)isoindolate (2), 1,3-bis(2-pyridylimino)benz(f)isoindolate (3), 1,3-bis(2-pyridylimino)benz(e)isoindolate (4), and 1,3-bis(1-isoquinolylimino) isoindolate (5). For this series of molecules, either a blue shift (2 and3) or a red shift (4 and 5) in absorption and emission maxima, relative to their respective nonbenzannulated compounds, was observed that depends on the site of benzannulation. Experimental data and first principles calculations suggest that a similar HOMO energy level and a destabilized or stabilized LUMO with benzannulation is responsible for the observed trends. A rationale for LUMO stabilization/destabilization is presented using simple molecular orbital theory. This explanation is expanded to describe other molecules with this unusual behavior.
Copyright Owner
American Chemical Society
Copyright Date
2010
Language
en
File Format
application/pdf
Recommended Citation
Hanson, Kenneth; Roskop, Luke; Djurovich, Peter I.; Zahariev, Federico; Gordon, Mark S.; and Thompson, Mark E., "A Paradigm for Blue- or Red-Shifted Absorption of Small Molecules Depending on the Site of π-Extension" (2010). Chemistry Publications. 531.
https://lib.dr.iastate.edu/chem_pubs/531
Comments
Reprinted (adapted) with permission from Journal of the American Chemical Society 132 (2010): 16247, doi:10.1021/ja1075162. Copyright 2010 American Chemical Society.