Paramagnet induced signal quenching in MAS-DNP experiments in frozen homogeneous solutions.

ABSTRACT: The effects of nuclear signal quenching induced by the presence of a paramagnetic polarizing agent are documented for conditions used in magic angle spinning (MAS)-dynamic nuclear polarization (DNP) experiments on homogeneous solutions. In particular, we present a detailed analysis of three time constants: (1) the longitudinal build-up time constant TB for (1)H; (2) the rotating frame relaxation time constant T1ρ for (1)H and (13)C and (3) T2 of (13)C, the transverse relaxation time constant in the laboratory frame. These relaxation times were measured during microwave irradiation at a magnetic field of 5 T (140 GHz) as a function of the concentration of four polarizing agents: TOTAPOL, 4-amino-TEMPO, trityl (OX063), and Gd-DOTA and are compared to those obtained for a sample lacking param

SUBMITTER: Corzilius B 

PROVIDER: S-EPMC3951579 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature