{"doi":"10.1021/jacs.3c08117","title":"Generation, Spectroscopic Characterization, and Computational Analysis of a Six-Coordinate Cobalt(III)-Imidyl Complex with an Unusual <i>S</i> = 3/2 Ground State that Promotes N-Group and Hydrogen Atom-Transfer Reactions with Exogenous Substrates","abstract":"We report the synthesis and characterization of a mononuclear nonheme cobalt(III)-imidyl complex, [Co(NTs)(TQA)(OTf)] + ( 1 ), with an S = 3/2 spin state that is capable of facilitating exogenous substrate modifications. Complex 1 was generated from the reaction of Co II (TQA)(OTf) 2 with PhINTs at −20 °C. A flow setup with ESI-MS detection was used to explore the kinetics of the formation, stability, and degradation pathway of 1 in solution by treating the Co(II) precursor with PhINTs. Co K-edge XAS data revealed a distinct shift in the Co K-edge compared to the Co(II) precursor, in agreement with the formation of a Co(III) intermediate. The unusual S = 3/2 spin state was proposed based on EPR, DFT, and CASSCF calculations and Co Kβ XES results. Co K-edge XAS and IR photodissociation (IRPD) spectroscopies demonstrate that 1 is a six-coordinate species, and IRPD and resonance Raman spectroscopies are consistent with 1 being exclusively the isomer with the NT ligand occupying the vacant site trans to the TQA aliphatic amine nitrogen atom. Electronic structure calculations (broken symmetry DFT and CASSCF/NEVPT2) demonstrate an S = 3/2 oxidation state resulting from the strong antiferromagnetic coupling of an • NTs spin to the high-spin S = 2 Co(III) center. Reactivity studies of 1 with PPh 3 derivatives revealed its electrophilic characteristic in the nitrene-transfer reaction. While the activation of C–H bonds by 1 was proved to be kinetically challenging, 1 could oxidize weak O–H and N–H bonds. Complex 1 is, therefore, a rare example of a Co(III)-imidyl complex capable of exogenous substrate transformations.","journal":"Journal of the American Chemical Society","year":2023,"id":350476,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":10,"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":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1094441,"name":"Guilherme L. Tripodi","orcid":"0000-0002-0132-8652","position":1,"is_corresponding":false},{"id":1094442,"name":"Max T. G. M. Derks","orcid":"0000-0002-6033-7057","position":2,"is_corresponding":false},{"id":676637,"name":"Mi Sook Seo","orcid":"0000-0003-3302-2508","position":3,"is_corresponding":false},{"id":676638,"name":"Yong‐Min Lee","orcid":"0000-0002-5553-1453","position":4,"is_corresponding":false},{"id":1094852,"name":"Kendal W. Southwell","orcid":null,"position":5,"is_corresponding":false},{"id":764694,"name":"Jason Shearer","orcid":"0000-0001-7469-7304","position":6,"is_corresponding":false},{"id":1094443,"name":"Jana Roithová","orcid":"0000-0001-5144-0688","position":7,"is_corresponding":false},{"id":676642,"name":"Wonwoo Nam","orcid":"0000-0001-8592-4867","position":8,"is_corresponding":false},{"id":1094440,"name":"Jindou Yang","orcid":"0000-0003-2146-3808","position":0,"is_corresponding":true}],"reference_count":143,"raw_metadata":null,"created_at":"2026-07-19T01:12:23.769679Z","pmid":"37997643","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":[]}