{"doi":"10.1021/acs.jpclett.7b03433","title":"Spontaneous<sup>15</sup>N Nuclear Spin Hyperpolarization in Metal-Free Activation of Parahydrogen by Molecular Tweezers","abstract":null,"journal":"The Journal of Physical Chemistry Letters","year":2018,"id":679902,"datarank":0.47032413238937254,"base_score":3.1354942159291497,"endowment":3.1354942159291497,"self_citation_contribution":0.47032413238937254,"citation_network_contribution":0.0,"self_endowment_contribution":0.47032413238937254,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":22,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":602374,"name":"Владимир В. Живонитко","orcid":"0000-0003-2919-8690","position":1,"is_corresponding":false},{"id":1776443,"name":"Konstantin Chernichenko","orcid":null,"position":2,"is_corresponding":false},{"id":602382,"name":"Ville‐Veikko Telkki","orcid":"0000-0003-0846-6852","position":3,"is_corresponding":false},{"id":1776444,"name":"Timo Repo","orcid":null,"position":4,"is_corresponding":false},{"id":602377,"name":"Igor V. Koptyug","orcid":"0000-0003-3480-7649","position":5,"is_corresponding":false},{"id":1776442,"name":"Kristina Sorochkina","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Spontaneous<sup>15</sup>N Nuclear Spin Hyperpolarization in Metal-Free Activation of Parahydrogen by Molecular Tweezers","abstract":"High Resolution Image Download MS PowerPoint Slide The ability of frustrated Lewis pairs (FLPs) to activate H 2 is of significant interest for metal-free catalysis. The activation of H 2 is also the key element of parahydrogen-induced polarization (PHIP), one of the nuclear spin hyperpolarization techniques. It is demonstrated that o -phenylene-based ansa -aminoboranes (AABs) can produce 1 H nuclear spin hyperpolarization through a reversible interaction with parahydrogen at ambient temperatures. Heteronuclei are useful in NMR and MRI as well because they have a broad chemical shift range and long relaxation times and may act as background-free labels. We report spontaneous formation of 15 N hyperpolarization of the N–H site for a family of AABs. The process is efficient at the high magnetic field of an NMR magnet (7 T), and it provides up to 350-fold 15 N signal enhancements. Different hyperpolarization effects are observed with various AAB structures and in a broad temperature range. Spontaneous hyperpolarization, albeit an order of magnitude weaker than that for 15 N, was also observed for 11 B nuclei.","is_dataset_classified":null,"base_score":3.1354942159291497,"endowment":3.1354942159291497,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"29401399","pmcid":"PMC5862329","openalex_id":"https://openalex.org/W2793236416","authors":[],"funders":[{"funder_name":"Russian Foundation for Basic Research","grant_id":"16-03-00407-a","title":null},{"funder_name":"Suomen Akatemia","grant_id":"276586","title":"Catalysis using Frustrated Lewis Pairs"},{"funder_name":"Suomen Akatemia","grant_id":"289649","title":"Ultrafast Multidimensional Laplace NMR"},{"funder_name":"Suomen Akatemia","grant_id":"294027","title":"Ultrafast Multidimensional Laplace NMR"},{"funder_name":"Suomen Akatemia","grant_id":"311604","title":"129Xe hyperpolarization technique based on parahydrogen-induced polarization"},{"funder_name":"H2020 European Research Council","grant_id":"772110","title":"Ultrafast Laplace NMR"},{"funder_name":"Federal Agency for Scientific Organizations","grant_id":"0333-2017-0002","title":null},{"funder_name":"Oulun Yliopisto","grant_id":"","title":null}],"total_grants":8,"fwci":0.9258,"citation_percentile":0.67778974,"influential_citations":0,"citation_trend":[{"year":2019,"count":3},{"year":2020,"count":3},{"year":2021,"count":2},{"year":2022,"count":4},{"year":2023,"count":2},{"year":2024,"count":3},{"year":2025,"count":4},{"year":2026,"count":1}],"oa_status":"bronze","license":"publisher-specific-oa","oa_locations":[{"url":"https://pubs.acs.org/doi/pdf/10.1021/acs.jpclett.7b03433","host_type":"journal"},{"url":"https://pubs.acs.org/doi/pdf/10.1021/acs.jpclett.7b03433","host_type":"publisher"},{"url":"http://pubs.acs.org/doi/pdf/10.1021/acs.jpclett.7b03433","host_type":"publisher"},{"url":"https://doi.org/10.1021/acs.jpclett.7b03433","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/29401399","host_type":"repository"},{"url":"https://www.ncbi.nlm.nih.gov/pmc/articles/5862329","host_type":"repository"},{"url":"http://hdl.handle.net/10138/301184","host_type":"journal"},{"url":"https://europepmc.org/articles/PMC5862329","host_type":"Europe_PMC"},{"url":"https://europepmc.org/articles/PMC5862329?pdf=render","host_type":"Europe_PMC"},{"url":"http://dx.doi.org/10.1021/acs.jpclett.7b03433","host_type":""},{"url":"https://dx.doi.org/10.1021/acs.jpclett.7b03433","host_type":""}],"fields_of_study":["Advanced NMR Techniques and Applications","Organoboron and organosilicon chemistry","Solid-state spectroscopy and crystallography","01 natural sciences","0104 chemical sciences"],"mesh_terms":[],"keywords":["Hyperpolarization (physics)","Spin isomers of hydrogen","Chemistry","Nuclear magnetic resonance","Induced polarization","Nuclear magnetic resonance spectroscopy","Stereochemistry","Physics","Hydrogen","SABRE","FRUSTRATED LEWIS PAIRS","ORDER","RELAXATION","NMR","PARA-HYDROGEN","Physical sciences","ALIGNMENT","P-31","Chemical sciences","MRI"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-17T14:00:09.641719Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}