A modular approach for the synthesis of nanometer-sized polynitroxide multi-spin systems

J Org Chem. 2014 Sep 5;79(17):8313-23. doi: 10.1021/jo5015678. Epub 2014 Aug 20.

Abstract

The synthesis of rigid symmetric polyradical model systems with inter-spin distances between 1.4 and 4 nm and their room temperature continuous wave (CW) EPR spectra are reported. Conditions for attachment of the spin-label via esterification have been optimized on the direct synthesis of polyradicals from commercially available polyphenols and the carboxylic acid functionalized nitroxide TPC. A common synthetic protocol utilizing 4-hydroxy-4'-iodobiphenyl as a key building block has been used to synthesize an equilateral biradical and a triradical in only two steps from commercially available starting materials. The first synthesis of a tetraradical based upon an adamantane core bearing six equivalent nitroxide-nitroxide distances is also reported. These systems are very promising candidates for studying multi-spin effects in pulsed EPR distance measurements.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Electron Spin Resonance Spectroscopy
  • Esterification
  • Nitrogen Oxides / chemical synthesis*
  • Nitrogen Oxides / chemistry
  • Polyphenols / chemistry*
  • Spin Labels
  • Temperature

Substances

  • Nitrogen Oxides
  • Polyphenols
  • Spin Labels