Dynamic nuclear polarization in highly fluorinated solutions


Ovalioglu H., PEKSÖZ A., ENGİN KIRIMLI H., Yalciner A.

Journal of Dispersion Science and Technology, cilt.31, sa.3, ss.332-337, 2010 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 31 Sayı: 3
  • Basım Tarihi: 2010
  • Doi Numarası: 10.1080/01932690903192572
  • Dergi Adı: Journal of Dispersion Science and Technology
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.332-337
  • Anahtar Kelimeler: Dynamic nuclear polarization, Epr spectra, Fluorine-electron double resonance, Free radical, Overhauser effect
  • Bursa Uludağ Üniversitesi Adresli: Evet

Özet

The Overhauser effect type dynamic nuclear polarization experiments were performed to study solutions of the stable free radical a,c-Bisdiphenylene-b-phenyl allyl complex with benzene (1:1) in some highly fluorinated aliphatic and aromatic solvents. In solutions examined in this study, it occurs mainly the Overhauser effect, which normally arises due to both dipolar and scalar interactions between the unpaired electrons of the free radical molecules and fluorine nuclei of solvent molecules. 1-Iodotridecafluorohexane, N-Methyl-bis-trifluoroacetamide, Octafluoroto- luene and Hexafluorobenzene were used as the solvents. The experiments were performed at a low field double resonance NMR spectrometer, which operates at 1.53 mT. The NMR enhancements depend on competition between intermolecular magnetic interactions. It was studied to investigate variation of EPR spectra with four different temperatures. It was found as temperature increases, peak points of EPR spectra decreases. © Taylor & Francis Group, LLC.