Abstract: The present invention relates to the field of organic chemistry and in particular to organic free radicals used as polarizing agents in the technique of Dynamic Nuclear Polarization (DNP), which involves transferring the polarization of electron spins to the nuclei of a compound whose Nuclear Magnetic Resonance (NMR) is being observed. It concerns Dinitroxide-type Biradical polarizing agents characterized by a rigid linkage between the aminoxyl groups of said nitroxide units. This particular structure enables, at low temperatures and high fields, optimal transfer of polarization and optimal enhancement of NMR/MAS signals of the polarized nuclei of the compound studied.

Abstract: The present invention relates to the field of organic chemistry and in particular to organic free radicals used as polarizing agents in the technique of Dynamic Nuclear Polarization (DNP), which involves transferring the polarization of electron spins to the nuclei of a compound whose Nuclear Magnetic Resonance (NMR) is being observed. It concerns Dinitroxide-type Biradical polarizing agents characterized by a rigid linkage between the aminoxyl groups of said nitroxide units. This particular structure enables, at low temperatures and high fields, optimal transfer of polarization and optimal enhancement of NMR/MAS signals of the polarized nuclei of the compound studied.

Abstract: The present invention relates to the field of organic chemistry and in particular to organic free radicals used as polarizing agents in the technique of Dynamic Nuclear Polarization (DNP), which involves transferring the polarization of electron spins to the nuclei of a compound whose Nuclear Magnetic Resonance (NMR) is being observed. It concerns dinitroxide-type biradical polarizing agents characterized by a rigid linkage between the nitroxide units that enables optimal orientation and distance to be maintained between the aminoxyl groups of said nitroxide units. This particular structure enables, at low temperatures and high fields, optimal transfer of polarization and optimal enhancement of NMR/MAS signals of the polarized nuclei of the compound studied.

Abstract: The present invention relates to the field of organic chemistry and in particular to organic free radicals used as polarizing agents in the technique of Dynamic Nuclear Polarization (DNP), which involves transferring the polarization of electron spins to the nuclei of a compound whose Nuclear Magnetic Resonance (NMR) is being observed. It concerns dinitroxide-type biradical polarizing agents characterized by a rigid linkage between the nitroxide units that enables optimal orientation and distance to be maintained between the aminoxyl groups of said nitroxide units. This particular structure enables, at low temperatures and high fields, optimal transfer of polarization and optimal enhancement of NMR/MAS signals of the polarized nuclei of the compound studied.

Abstract: Linear or cyclic aminophosphonates are disclosed which are useful as pH markers. A method of using the linear or cyclic aminophosphonates in phosphorus-31 NMR spectroscopy is also disclosed.

Abstract: New nitrones which are usable for the scavaging of free radicals, are selected from 5-diethoxyphosphoryl-5-methyl-1-pyrroline 1-oxide, 5-phosphono-5-methyl-1-pyrroline 1-oxide, and 5-diethoxyphosphoryl-5-methyl-(2,3,3-.sup.2 H.sub.3)-1-pyrroline 1-oxide, as well as its corresponding physiologically acceptable salts obtained by the action of an inorganic or organic base.

Abstract: A nitroxide radical of the formula (I) or (II): ##STR1## in which R.sub.1 and R.sub.2 are independently chosen from among the optionally deuterated alkyl, alkoxyl, dialkylaminyl and phenyl radicals, H, D or Cl; R.sub.3, R.sub.8 and R.sub.9 are independently chosen from among the optionally deuterated alkyl, alkoxyl and phenyl radicals; R.sub.4, R.sub.5, R.sub.6 and R.sub.7 are independently chosen from among the optionally deuterated alkyl, alkoxyl, dialkylaminyl and phenyl radicals, COOH, OH, OD, H, D, a halogen, COOR (in which R is an alkyl radical); R.sub.10 and R.sub.11 are independently chosen from among optionally deuterated alkyl, alkoxyl, dialkylaminyl and phenyl radicals, COOH, OH, OD, H, D, a halogen, COOR (in which R is an alkyl radical) or represent an oxygen atom linked with the cycle of the radical by a double bond is described.