biostudies-literatureTrofimov IABundesministerium für Bildung und Forschung (Federal Ministry of Education and Research)Bundesministerium für Bildung und ForschungNIBIB NIH HHSNHLBI NIH HHSNational Science Foundation (NSF)EC | European Regional Development Fund (Europski Fond za Regionalni Razvoj)Deutsche ForschungsgemeinschaftDeutsche Forschungsgemeinschaft (German Research Foundation)Russian Science Foundation (RSF)EC | European Regional Development FundWayne State UniversityRussian Science FoundationNational Science FoundationGerman Cancer Consortium (DKTK), the DKTK Joint Funding project “HYPERBOLIC”235https://www.ebi.ac.uk/biostudies/studies/S-EPMC11484792biostudies-literatureUnknown7(1)Radio Amplification by Stimulated Emission of Radiation (RASER) is a phenomenon observed during nuclear magnetic resonance (NMR) experiments with strongly negatively polarized systems. This phenomenon may be utilized for the production of very narrow NMR lines, background-free NMR spectroscopy, and excitation-free sensing of chemical transformations. Recently, novel methods of producing RASER by ParaHydrogen-Induced Polarization (PHIP) were introduced. Here, we show that pairwise addition of parahydrogen to various propargylic compounds induces RASER activity of other protons beyond those chemically introduced in the reaction. In high-field PHIP, negative polarization initiating RASER is transferred via intramolecular cross-relaxation. When parahydrogen is added in Earth's field followed by adiabatic transfer to a high field, RASER activity of other protons is induced via both J-couplings and cross-relaxation. This through-bond and through-space induction of RASER holds potential for the ongoing development and expansion of RASER applications and can potentially enhance spectral resolution in two-dimensional NMR spectroscopy techniques.Communications chemistryThrough-bond and through-space radiofrequency amplification by stimulated emission of radiation.PMC11484792Postdoctoral Fellow award#22-43-04426122-09-053R01 EB03419713N16448#SCHM 3694/1, #SCHM 3694/2, #SFB1479, Project ID: 441891347SFB1160PR 1868/3-1, PR 1868/5-1, HO-4602/2-2, HO-4602/3, EXC2167, FOR5042, TRR287CHE-1904780, NIBIB R01EB034197, NHLBI 1R21HL154032, DOD CDMRP W81XWH-20-1057601ZX1915CR21 HL154032Pravdivtsev ANChekmenev EYde Maissin HSchmidt ABYi APTrofimov IAKoptyug IVSalnikov OGHovener JBfalseThrough-bond and through-space radiofrequency amplification by stimulated emission of radiation.Radio Amplification by Stimulated Emission of Radiation (RASER) is a phenomenon observed during nuclear magnetic resonance (NMR) experiments with strongly negatively polarized systems. This phenomenon may be utilized for the production of very narrow NMR lines, background-free NMR spectroscopy, and excitation-free sensing of chemical transformations. Recently, novel methods of producing RASER by ParaHydrogen-Induced Polarization (PHIP) were introduced. Here, we show that pairwise addition of parahydrogen to various propargylic compounds induces RASER activity of other protons beyond those chemically introduced in the reaction. In high-field PHIP, negative polarization initiating RASER is transferred via intramolecular cross-relaxation. When parahydrogen is added in Earth's field followed by adiabatic transfer to a high field, RASER activity of other protons is induced via both J-couplings and cross-relaxation. This through-bond and through-space induction of RASER holds potential for the ongoing development and expansion of RASER applications and can potentially enhance spectral resolution in two-dimensional NMR spectroscopy techniques.2024-01-01T00:00:00Z2024 Oct2025-04-04T02:54:35.38Z2025-04-04T02:54:35.38ZS-EPMC114847923941491210.1038/s42004-024-01313-0