Parahydrogen induced polarization of barbituric acid derivatives: 1H hyperpolarization studies |
| |
Authors: | Roth Meike Bargon Joachim Spiess Hans Wolfgang Koch Achim |
| |
Affiliation: | Max-Planck-Institute for Polymer Research, NMR Division, Postfach 3148, D-55021 Mainz, Germany. |
| |
Abstract: | Homogeneous hydrogenation of barbituric acid derivatives with parahydrogen yields a substantial increase of the (1)H NMR signals of the reaction products. These physiologically relevant compounds were hydrogenated at both ambient and elevated temperatures and pressures using a standard cationic rhodium catalyst. The resulting nonthermal nuclear spin polarization (hyperpolarization) is limited by the spin-lattice relaxation time T(1) of the corresponding nuclei in the products, being shorter than the time constant of the hydrogenation. The signal-to-noise ratio of the NMR spectra could be further increased upon signal averaging the antiphase PHIP signals of 25 successive scans following 30 degrees pulse experiments and a delay of 10 s. |
| |
Keywords: | NMR 1H‐NMR PHIP‐NMR homogeneous catalysis barbituric acid signal averaging |
本文献已被 PubMed 等数据库收录! |