Electrochemical behavior of the tris(pyridine)-Cu funnel complexes: an overall induced-fit process involving an entatic state through a supramolecular stress

J Am Chem Soc. 2005 Apr 20;127(15):5280-1. doi: 10.1021/ja043073h.

Abstract

The electrochemical behavior of the tris(pyridine) calix[6]arene Cu adducts is unique as compared to that of most classical Cu complexes in a strain-free environment. The presence of MeCN buried inside the cavity is a prerequisite for a quasi-reversible behavior in a dynamic mode. The CV behavior assisted by simulation outlines that the coordination adaptability of the Cu(II)/Cu(I) redox states is completely reversed, with a Td geometry enforced at either redox states. Hence, the supramolecular control of the Cu coordination by a protein-like pocket determines the dynamics of the electron transfer process, its thermodynamics, and the kinetics of the reorganizational barrier and generates a preorganized state for oxidation. This redox behavior corresponds to an overall induced-fit process generating a truly entatic highly oxidizing Cu(II) state through a protein-like strain by involvement of the secondary coordination sphere.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biomimetic Materials / chemistry
  • Calixarenes / chemistry*
  • Copper / chemistry*
  • Electrochemistry
  • Electron Spin Resonance Spectroscopy
  • Hydrophobic and Hydrophilic Interactions
  • Kinetics
  • Organometallic Compounds / chemistry
  • Oxidation-Reduction
  • Phenols / chemistry*
  • Pyridines / chemistry*

Substances

  • Organometallic Compounds
  • Phenols
  • Pyridines
  • calix(6)arene
  • Calixarenes
  • Copper