Programmed metalloporphyrins for self-assembly within light-harvesting stacks: (5,15-dicyano-10,20-bis(3,5-di-tert-butylphenyl)porphyrinato)zinc(II) and its push-pull 15-N,N-dialkylamino-5-cyano congeners obtained by a facile direct amination

J Phys Chem B. 2008 May 1;112(17):5512-21. doi: 10.1021/jp801510b. Epub 2008 Apr 11.

Abstract

The title dicyano compound was synthesized via cyanation and it self-assembles in nonpolar solvents giving red-shifted and broad absorption maxima just as the bacteriochlorophylls which are encountered in the light-harvesting organelles of early photosynthetic bacteria. In the crystal, stacks are formed through a hierarchic combination of pi-stacking and a CN-Zn electrostatic interaction. Push-pull 15-N,N-dialkylamino-5-cyano congeners could be obtained in high yields using a solvent- and catalyst-free direct amination of meso-bromoporphyrins. Importantly, the fluorescence of the self-assembled species due to the very orderly manner in which the chromophores are arranged is not entirely quenched and has a surprisingly long lifetime of over 1 ns. This lends hope of using the trapped energy in biomimetic hybrid solar cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amination
  • Crystallization
  • Crystallography, X-Ray
  • Light*
  • Metalloporphyrins / chemistry*
  • Models, Biological*
  • Molecular Structure
  • Organelles / chemistry
  • Photochemistry
  • Spectrometry, Fluorescence
  • Spectrophotometry

Substances

  • (5,15-dicyano-10,20-bis(3,5-di-tert-butylphenyl)porphyrinato)zinc(II)
  • Metalloporphyrins