Electron paramagnetic resonance of the excited states of the three-spins-1/2 ZnTPP-3-NOPy complex

Spectrochim Acta A Mol Biomol Spectrosc. 2008 May;69(5):1327-30. doi: 10.1016/j.saa.2007.09.026. Epub 2007 Oct 2.

Abstract

EPR spectra of the excited quartet and doublet molecular states of (tetraphenylporphinato)zinc(II) covalently bounded to 3-(N-nitronyl-notroxide) pyridine stable radical are modeled in terms of the spin-Hamiltonian given by the sum of the contributions from the radical and triplet moieties, and the interaction between them. The later is represented by anisotropic point dipolar and isotropic exchange electron spin-spin interactions. It is shown that the high field (W-band) EPR spectra depend on energy separation between the electronic doublet (D) and quartet (Q) states. This dependence was utilized to estimate the upper limit of the intensity of exchange interaction between the radical and porphyrin moieties.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Computer Simulation
  • Electron Spin Resonance Spectroscopy
  • Metalloporphyrins / chemistry*
  • Molecular Conformation
  • Porphyrins / chemistry*
  • Spin Labels*
  • Thermodynamics
  • Time Factors

Substances

  • Metalloporphyrins
  • Porphyrins
  • Spin Labels