%AAlam, Md [School of Chemical and Biomolecular Sciences Southern Illinois University Carbondale 1245 Lincoln Dr. Carbondale IL-62901 USA]%ALi, Xinlin [School of Chemical and Biomolecular Sciences Southern Illinois University Carbondale 1245 Lincoln Dr. Carbondale IL-62901 USA]%ABrittin, Drew [School of Chemical and Biomolecular Sciences Southern Illinois University Carbondale 1245 Lincoln Dr. Carbondale IL-62901 USA]%AIslam, Saiful [School of Chemical and Biomolecular Sciences Southern Illinois University Carbondale 1245 Lincoln Dr. Carbondale IL-62901 USA]%ADeria, Pravas [School of Chemical and Biomolecular Sciences Southern Illinois University Carbondale 1245 Lincoln Dr. Carbondale IL-62901 USA]%AChekmenev, Eduard [Department of Chemistry Karmanos Cancer Institute, Integrative Biosciences Wayne State University Detroit MI USA, Russian Academy of Sciences Leninskiy Prospekt 14 Moscow 119991 Russia]%AGoodson, Boyd [School of Chemical and Biomolecular Sciences Southern Illinois University Carbondale 1245 Lincoln Dr. Carbondale IL-62901 USA, Materials Technology Center Southern Illinois University 1245 Lincoln Drive Carbondale IL 62901 USA]%BJournal Name: Angewandte Chemie; Journal Volume: 135; Journal Issue: 8; Related Information: CHORUS Timestamp: 2023-08-17 08:45:34 %D2023%IWiley Blackwell (John Wiley & Sons) %JJournal Name: Angewandte Chemie; Journal Volume: 135; Journal Issue: 8; Related Information: CHORUS Timestamp: 2023-08-17 08:45:34 %K %MOSTI ID: 10390922 %PMedium: X %TAnomalously Large Antiphase Signals from Hyperpolarized Orthohydrogen Using a MOF‐Based SABRE Catalyst %XAbstract

Hyperpolarized orthohydrogen (o‐H2) is a frequent product of parahydrogen‐based hyperpolarization approaches like signal amplification by reversible exchange (SABRE), where the hyperpolarizedo‐H2signal is usually absorptive. We describe a novel manifestation of this effect wherein large antiphaseo‐H2signals are observed, with1H enhancements up to ≈500‐fold (effective polarizationPH≈1.6 %). This anomalous effect is attained only when using an intact heterogeneous catalyst constructed using a metal–organic framework (MOF) and is qualitatively independent of substrate nature. This seemingly paradoxical observation is analogous to the “partial negative line” (PNL) effect recently explained in the context of Parahydrogen Induced Polarization (PHIP) by Ivanov and co‐workers. The two‐spin order of theo‐H2resonance is manifested by a two‐fold higher Rabi frequency, and the lifetime of the antiphase HPo‐H2resonance is extended by several‐fold.

%0Journal Article