{"doi":"10.26434/chemrxiv.13249889","title":"Activation of Ammonia and Hydrazine by Electron Rich Fe(II) Complexes Supported by a Dianionic Pentadentate Ligand Platform Through a Common Terminal Fe(III) Amido Intermediate","abstract":"We report the use of electron rich iron complexes supported by a dianionic diborate pentadentate ligand system, B2Pz4Py, for the coordination and activation of ammonia (NH3) and hydrazine (NH2NH2). For ammonia, coordination to neutral (B2Pz4Py)Fe(II) or cationic [(B2Pz4Py)Fe(III)]+ platforms leads to well characterized ammine complexes from which hydrogen atoms or protons can be removed to generate, fleetingly, a proposed (B2Pz4Py)Fe(III)- NH2 complex (3Ar-NH2). DFT computations suggest a high degree of spin density on the amido ligand, giving it significant aminyl radical character. It rapidly traps the H atom abstracting agent 2,4,6-tri-tert-butylphenoxy radical (ArO•) to form a C-N bond in a fully characterized product (2Ar), or scavenges hydrogen atoms to return to the ammonia complex (B2Pz4Py)Fe(II)-NH3 (1ArNH3). Interestingly, when (B2Pz4Py)Fe(II) is reacted with NH2NH2, a fully characterized bridging diazene complex, 4Ar, is formed along with ammonia adduct 1Ar-NH3 as the spectroscopically observed (-78˚C) (B2Pz4Py)Fe(II)-NH2NH2-Fe(II)( B2Pz4Py) dimer (1Ar)2-NH2NH2 is allowed to warm to room temperature. Experimental and computational evidence is presented to suggest that (B2Pz4Py)Fe(II) induces reductive cleavage of the N-N bond in hydrazine to produce the Fe(III)-NH2 complex 3Ar-NH2, which abstracts H• atoms from (1Ar)2-NH2NH2 to generate the observed products. All of these transformations are relevant to proposed steps in the ammonia oxidation reaction, an important process for the use of nitrogen-based fuels enabled by abundant first row transition metals. <br>","journal":"ChemRxiv","year":2020,"id":134366,"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":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9531,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2020-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":572959,"name":"Yan Yang","orcid":"0000-0002-0113-1569","position":1,"is_corresponding":false},{"id":573386,"name":"Peter Neate","orcid":null,"position":2,"is_corresponding":false},{"id":471020,"name":"Warren E. Piers","orcid":"0000-0003-2278-1269","position":3,"is_corresponding":false},{"id":471021,"name":"Laurent Maron","orcid":"0000-0003-2653-8557","position":4,"is_corresponding":false},{"id":371413,"name":"Michael L. Neidig","orcid":"0000-0002-2300-3867","position":5,"is_corresponding":false},{"id":471022,"name":"Jian‐Bin Lin","orcid":"0000-0002-3117-1959","position":6,"is_corresponding":false},{"id":471023,"name":"Benjamin S. Gelfand","orcid":"0000-0001-6599-6310","position":7,"is_corresponding":false},{"id":472184,"name":"Lucie Nurdin","orcid":null,"position":0,"is_corresponding":true}],"reference_count":57,"raw_metadata":null,"created_at":"2026-07-18T23:16:24.540681Z","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":[]}