Photoinitiated charge transport in supramolecular assemblies of a 1,7,N,N'-tetrakis(zinc porphyrin)-perylene-3,4:9,10-bis(dicarboximide)

J Am Chem Soc. 2007 Mar 21;129(11):3173-81. doi: 10.1021/ja0664741. Epub 2007 Feb 24.

Abstract

We report the synthesis and photophysical characterization of a multichromophore array, (Z3PN)4PDI, consisting of four zinc 5-phenyl-10,15,20-tri(n-pentyl)porphyrins (Z3PN) attached to the 1,7,N,N'-positions of perylene-3,4:9,10-bis(dicarboximide) (PDI). The dynamics of energy and charge transport within this system were compared to those of two model compounds, N,N'-(Z3PN)2PDI and 1,7-(Z3PN)2PDI. The symmetry of the lowest unoccupied and highest occupied molecular orbitals of PDI results in significantly different electronic couplings between Z3PN and PDI when they are connected at the 1,7-positions vs the N,N'-positions of PDI. This results in two distinct pathways for electron transfer in (Z3PN)4PDI. Using a combination of metal-ligand binding with the bidentate ligand 1,4-diazabicyclo[2.2.2.]octane (DABCO) and pi-pi stacking, (Z3PN4)PDI forms a supramolecular assembly, [[(Z3PN)4PDI]2-DABCO4]2, in toluene solution. The structure of this hierarchical assembly is characterized with the use of solution-phase X-ray scattering techniques and demonstrates both efficient light harvesting and facile charge separation and transport using multiple pathways.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Imides / chemistry*
  • Metalloporphyrins / chemistry*
  • Models, Molecular
  • Perylene / chemistry
  • Photochemistry
  • Scattering, Radiation
  • Spectrum Analysis
  • Thermodynamics
  • X-Rays
  • Zinc / chemistry*

Substances

  • Imides
  • Metalloporphyrins
  • Perylene
  • Zinc