title: Polychlorinated trityl radicals for dynamic nuclear polarization: the role of chlorine nuclei.
abstract: Polychlorinated trityl radicals bearing carboxylate substituents are water soluble persistent radicals that can be used for dynamic nuclear polarization. In contrast to other trityl radicals, the polarization mechanism differs from the classical solid effect. DFT calculations performed to rationalize this behaviour support the hypothesis that polarization is transferred from the unpaired electron to chlorine nuclei and from these to carbon by spin diffusion. The marked differences observed between neutral and anionic forms of the radical will be discussed.
authors.affiliation: Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Paniagua
authors.forename: Verónica
authors.initials: V
authors.lastname: Mugnaini
authors.forename: Cristina
authors.initials: C
authors.lastname: Gabellieri
authors.forename: Miguel
authors.initials: M
authors.lastname: Feliz
authors.forename: Nans
authors.initials: N
authors.lastname: Roques
authors.forename: Jaume
authors.initials: J
authors.lastname: Veciana
authors.forename: Miquel
authors.initials: M
authors.lastname: Pons
mesh_terms: D002713:Chlorine / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011080:Polychloroterphenyl Compounds / Q000737:chemistry*
chemical_list: D005609:Free Radicals; D011080:Polychloroterphenyl Compounds; D002713:Chlorine