{"doi":"10.1021/jacs.4c11034","title":"Experimental Definition of the <i>S</i> = 1 π vs <i>S</i> = 2 σ Reactivity and <i>S</i> = 2 Character in the Ground State of an <i>S</i> = 1 Fe<sup>IV</sup>O Complex","abstract":"Iron(IV)-oxo intermediates found in iron enzymes and artificial catalysts are competent for H atom abstraction in catalytic cycles. For S = 2 intermediates, both axial and equatorial approaches are well-established. The mechanism for S = 1 sites is not as well understood: an equatorial approach is more energetically favorable, and an axial approach requires crossing from the S = 1 to the S = 2 surface. In this study, we use 1s2p resonant inelastic X-ray scattering (RIXS) and Fe L-edge X-ray absorption spectroscopy on the S = 1 [Fe IV O(TMC)(CH 3 CN)] 2+ and observe both S = 2 and S = 1 final states, which enables the experimental evaluation of the energetics of the axial and equatorial reactivity of an S = 1 Fe IV O center on its S = 2 vs S = 1 surface. The observation of S = 2 final states in the RIXS spectrum demonstrates significant S = 2 character spin–orbit mixed into the S = 1 ground state.","journal":"Journal of the American Chemical Society","year":2024,"id":456917,"datarank":0.29188652235829704,"base_score":1.9459101490553132,"endowment":1.9459101490553132,"self_citation_contribution":0.29188652235829704,"citation_network_contribution":0.0,"self_endowment_contribution":0.29188652235829704,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":6,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9574,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2024-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":299419,"name":"Leland B. Gee","orcid":"0000-0002-5817-3997","position":1,"is_corresponding":false},{"id":1281764,"name":"Max D. J. Waters","orcid":"0000-0002-3505-627X","position":2,"is_corresponding":false},{"id":414292,"name":"Michael L. Baker","orcid":"0000-0002-8246-3177","position":3,"is_corresponding":false},{"id":699359,"name":"Michael W. Mara","orcid":"0000-0003-3766-9368","position":4,"is_corresponding":false},{"id":1281765,"name":"Ang Zhou","orcid":"0000-0003-1450-9169","position":5,"is_corresponding":false},{"id":414297,"name":"Thomas Kröll","orcid":"0000-0003-2176-6905","position":6,"is_corresponding":false},{"id":484772,"name":"Dennis Nordlund","orcid":"0000-0001-9524-6908","position":7,"is_corresponding":false},{"id":414298,"name":"Dimosthenis Sokaras","orcid":"0000-0001-8117-1933","position":8,"is_corresponding":false},{"id":362848,"name":"Britt Hedman","orcid":null,"position":9,"is_corresponding":false},{"id":361415,"name":"Keith O. Hodgson","orcid":"0000-0003-3059-8931","position":10,"is_corresponding":false},{"id":514407,"name":"Lawrence Que","orcid":"0000-0002-0989-2813","position":11,"is_corresponding":false},{"id":271050,"name":"Edward I. Solomon","orcid":"0000-0003-0291-3199","position":12,"is_corresponding":false},{"id":665151,"name":"Augustin Braun","orcid":"0000-0002-9487-5769","position":0,"is_corresponding":true}],"reference_count":25,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-19T02:03:32.516678Z","pmid":"39668699","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":[]}