Spin dynamics of [1,2-13C2]pyruvate hyperpolarization by parahydrogen in reversible exchange at micro Tesla fields

Hyperpolarization of C-13-pyruvate via Signal Amplificaton By Reversibble Exchange (SABRE) is an important recent discovery because of both the relative simplicity of hyperpolarization and the central biological relevance of pyruvate as a biomolecular probe for in vitro or in vivo studies. Here, we analyze the [1,2-C-13(2)]pyruvate-SABRE spin system and its field dependence theoretically and experimentally. We provide first-principles analysis of the governing 4-spin dihydride-C-13(2) Hamiltonian and numerical spin dynamics simulations of the 7-spin dihydride-C-13(2)-CH3 system. The analytical and the numerical results are compared to matching systematic experiments. With these methods we unravel the observed spin state mixing of singlet states and triplet states at microTesla fields and we also analyze the dynamics during transfer from micro-Tesla field to high field for detection to understand the resulting spectra from the [1,2-C-13(2)]pyruvate-SABRE system.

Automated summary

Hyperpolarization of C-13-pyruvate via Signal Amplification By Reversible Exchange (SABRE) is an important recent discovery due to the simplicity of hyperpolarization and the relevance of pyruvate as a biomolecular probe. This study analyzes the [1,2-C-13(2)]pyruvate-SABRE spin system theoretically and experimentally, providing insights into spin state mixing, dynamics, and resulting spectra. The results are compared to systematic experiments, enhancing our understanding of the [1,2-C-13(2)]pyruvate-SABRE system.