Department of Physics, University of Pavia , Via Bassi 6, 27100 Pavia, Italy.
Department of Chemistry, Materials, and Chemical Engineering G. Natta, Politecnico of Milano , Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
J Phys Chem B. 2017 Mar 30;121(12):2584-2593. doi: 10.1021/acs.jpcb.7b00836. Epub 2017 Mar 17.
H dynamic nuclear polarization and nuclear spin-lattice relaxation rates have been studied in amorphous complexes of β-cyclodextrins doped with different concentrations of the TEMPO radical. Nuclear polarization increased up to 10% in the optimal case, with a behavior of the buildup rate (1/T) and of the nuclear spin-lattice relaxation rate (1/T) consistent with a thermal mixing regime. The temperature dependence of 1/T and its increase with the radical concentration indicate a relaxation process arising from the modulation of the electron-nucleus coupling by the glassy dynamics. The high-temperature relaxation is driven by molecular motions, and 1/T was studied at room temperature in liquid solutions for dilution levels close to the ones typically used for in vivo studies.
H 动态度极化和核自旋晶格弛豫率已在掺杂不同浓度 TEMPO 自由基的β-环糊精无定形复合物中进行了研究。在最佳情况下，核极化增加了 10%，其积累速率（1/T）和核自旋晶格弛豫速率（1/T）的行为与热混合状态一致。1/T 的温度依赖性及其随自由基浓度的增加表明，弛豫过程源于玻璃态动力学对电子-核耦合的调制。高温弛豫由分子运动驱动，并且在接近通常用于体内研究的稀释水平的液体溶液中在室温下研究了 1/T。
