Diarylurea-linked zinc porphyrin dimer as a dual-mode artificial receptor: supramolecular control of complexation-facilitated photoinduced electron transfer

J Am Chem Soc. 2003 Apr 9;125(14):4068-9. doi: 10.1021/ja0294717.

Abstract

A novel porphyrinic receptor 1 in which two zinc porphyrins are bridged by two diarylurea linkers was developed for recognition of a viologen derivative (hexyl viologen, HV). The electronic absorption spectra as well as the 1H NMR experiments revealed that the HV molecule was bound to the cleft in 1 mainly through carbonyl dipole-charge interactions to afford a 1:1 complex. From the steady-state fluorescence spectroscopic study, the photoinduced electron transfer (PET) from 1 to HV was extremely facilitated by the receptor-substrate complexation. The receptor 1 also formed a 1:1 complex with 1,4-diazabicyclo[2.2.2]octane (DABCO) through two Zn-N coordination interactions, and, using DABCO as an inhibitor, we suppressed the PET reaction via the substrate exchange.

MeSH terms

  • Biomimetic Materials / chemistry*
  • Electrons
  • Kinetics
  • Metalloporphyrins / chemistry*
  • Photochemistry
  • Piperazines / chemistry
  • Spectrometry, Fluorescence
  • Urea / analogs & derivatives*
  • Urea / chemistry
  • Viologens / chemistry

Substances

  • Metalloporphyrins
  • Piperazines
  • Viologens
  • zinc hematoporphyrin
  • Urea
  • triethylenediamine