Study of the contact charge transfer behavior between cryptophanes (A and E) and fullerene by absorption, fluorescence and 1H NMR spectroscopy

Anal Chim Acta. 2009 Sep 14;650(1):118-23. doi: 10.1016/j.aca.2009.02.046. Epub 2009 Mar 9.

Abstract

A group of novel cage-like compounds cryptophanes A and E were synthesized from vanillin by a three-step method. The intermolecular interaction between cryptophanes (A and E) and fullerene (C(60)) was investigated in detail by absorption, fluorescence and (1)H NMR spectroscopy. The absorption of C(60) at 410-650 nm decreased in the presence of cryptophanes A or E. The decrease in absorption intensity was proportional to the concentration of cryptophanes A or E. On the other hand, the fluorescence intensity of cryptophanes A or E decreased and the emission maxima were blue-shifted with the increase in C(60) concentration. These results suggest that contact charge transfer (CCT) complexes can be formed from C(60) with cryptophanes A or E. In addition, the electrochemical behavior of cryptophanes (A and E) and C(60) was studied by cyclic voltammetry. The redox currents of cryptophanes (A and E) decreased and the peak potentials were shifted on addition of C(60). The changes in the chemical shifts (Delta delta) of aromatic protons of cryptophanes (A and E) in their NMR spectra further support that CCT complexes were formed with cryptophanes as the electron donors and C(60) as the electron acceptor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorption
  • Fullerenes / chemistry*
  • Magnetic Resonance Spectroscopy
  • Oxidation-Reduction
  • Polycyclic Compounds / chemical synthesis
  • Polycyclic Compounds / chemistry*
  • Spectrometry, Fluorescence
  • Triazoles / chemistry*

Substances

  • Fullerenes
  • Polycyclic Compounds
  • Triazoles
  • cryptophane
  • cryptophane A
  • cryptophane E