Photophysical and electrochemical properties of meso-substituted thien-2-yl Zn(II) porphyrins

J Phys Chem A. 2008 Nov 20;112(46):11611-8. doi: 10.1021/jp805809p. Epub 2008 Oct 29.

Abstract

The influence of the thiophene ring on the ground and excited state properties of the porphyrin ring is investigated, when substituted at the meso-position. A series of mono-, di-, tri-, and tetra- meso-thien-2-yl porphyrins are studied and discussed with respect to the reference compounds zinc(II)-5,10,15,20-tetra(thien-2'-yl)porphyrin ( 1a) and zinc(II)-5,10,15,20-tetraphenylporphyrin (ZnTPP). The extended conjugated system zinc(II)-5-(5'-(5''-ethynyl-2''-thiophenecarboxaldehyde)thien-2'-yl)-10,15,20-triphenylporphyrin ( 4d) is also studied and shows enhanced charge transfer character due to the presence of the terminal aldehyde accepting group. A detailed analysis of ground and excited state UV-vis absorption, steady-state and time-resolved fluorescence, laser flash photolysis, and electrochemical data all point toward substantial electronic communication between the central Zn(II) porphyrin ring and the meso-thien-2-yl substituents, which is evident from excited state charge transfer character.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorption
  • Electrochemistry
  • Fluorescence
  • Magnetic Resonance Spectroscopy
  • Metalloporphyrins / chemistry*
  • Spectrophotometry, Ultraviolet
  • Time Factors
  • Zinc / chemistry*

Substances

  • Metalloporphyrins
  • Zinc