Dynamic Nuclear Polarization with Biradicals

Citations Over TimeTop 15% of 2004 papers

Abstract

Dynamic nuclear polarization (DNP) experiments in rotating solids have been performed for the first time using biradicals rather than monomeric paramagnetic centers as polarizing agents. Specifically, two TEMPO radicals were tethered with a poly(ethylene glycol) chain of variable length where the number of glycol units was 2, 3, or 4. NMR experiments show that the signal observed in DNP experiments is approximately inversely proportional to the length of the chain. Thus, the shorter chain with larger electron dipolar couplings yields larger enhancements. The size of the enhancement is a factor of 4 larger than obtained with the identical concentration of monomeric nitroxide radicals achieving a value of approximately 175 for the n = 2 chain.

Related Papers

• → Electrospray mass spectrometry of stable iminyl nitroxide and nitronyl nitroxide free radicals(2002)11 cited
• → Trapping Sites of Polypropylene Mechano-Radicals(1978)23 cited
• → The electron spin resonance spectra of radicals obtained by the addition of amino- and hydroxyl radicals to alkenes(1967)22 cited
• → Pharmacokinetic properties of nitroxide-labeled albumin in mice(1994)10 cited
• → Nitroxide biradicals from substituted bis(hydroxy‐ureas)(1979)3 cited