SABRE Hyperpolarization of Exchangeable Protons in Methanol- d4 through Dynamic Covalent Bonds

Xiao Zhan; Zhanhong Guo; Huijun Sun; Anran Dai; Min Zhang; Xiaohong Cui; Xinchang Wang; Zhongqun Tian; Zhong Chen

doi:10.1021/acs.analchem.3c01049

SABRE Hyperpolarization of Exchangeable Protons in Methanol- d₄ through Dynamic Covalent Bonds

Anal Chem. 2023 Aug 8;95(31):11613-11620. doi: 10.1021/acs.analchem.3c01049. Epub 2023 Jul 24.

Authors

Xiao Zhan¹, Zhanhong Guo¹, Huijun Sun¹, Anran Dai¹, Min Zhang², Xiaohong Cui^{1

2}, Xinchang Wang^{1

2

3}, Zhongqun Tian^{2

3}, Zhong Chen^{1

2

3}

Affiliations

¹ School of Electronic Science and Engineering, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen 361005, China.
² State Key Laboratory for Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
³ Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen 361005, China.

PMID: 37488664
DOI: 10.1021/acs.analchem.3c01049

Abstract

Utilizing para-hydrogen (p-H₂)-induced hyperpolarization to increase the sensitivity of nuclear magnetic resonance, especially signal amplification by reversible exchange (SABRE), has been widely studied. Here, we achieved hyperpolarization of exchangeable protons in methanol-d₄ by introducing dynamic covalent bonds as reversible exchange following the SABRE process. To release the hyperpolarized CD₃OH, the pyridine-based ligands with aldehyde groups underwent acetal exchange between the aldehyde and hydroxyl groups of CD₃OH after being first hyperpolarized by SABRE. Our mechanistic study highlights the importance of the reversible exchange of functional groups and chemical kinetics in realizing hyperpolarization of exchangeable protons in methanol-d₄. Our work broadens SABRE's chemical system compatibility and possible applications.