{"database":"biostudies-literature","file_versions":[],"scores":null,"additional":{"submitter":["Powers TM"],"funding":["NIGMS NIH HHS"],"pagination":["12289-96"],"full_dataset_link":["https://www.ebi.ac.uk/biostudies/studies/S-EPMC3801182"],"repository":["biostudies-literature"],"omics_type":["Unknown"],"volume":["135(33)"],"pubmed_abstract":["High-spin trinuclear iron complex ((tbs)L)Fe3(thf) ([(tbs)L](6-) = [1,3,5-C6H9(NC6H4-o-NSi(t)BuMe2)3](6-)) (S = 6) facilitates 2 and 4e(-) reduction of NxHy type substrates to yield imido and nitrido products. Reaction of hydrazine or phenylhydrazine with ((tbs)L)Fe3(thf) yields triiron ?(3)-imido cluster ((tbs)L)Fe3(?(3)-NH) and ammonia or aniline, respectively. ((tbs)L)Fe3(?(3)-NH) has a similar zero-field (57)Fe Mössbauer spectrum compared to previously reported [((tbs)L)Fe3(?(3)-N)]NBu4, and can be directly synthesized by protonation of the anionic triiron nitrido with lutidinium tetraphenylborate. Deprotonation of the triiron parent imido ((tbs)L)Fe3(?(3)-NH) with lithium bis(trimethylsilyl)amide results in regeneration of the triiron nitrido complex capped with a thf-solvated Li cation [((tbs)L)Fe3(?(3)-N)]Li(thf)3. The lithium capped nitrido, structurally similar to the pseudo C3-symmetric triiron nitride with a tetrabutylammonium countercation, is rigorously C3-symmetric featuring intracore distances of Fe-Fe 2.4802(5) Å, Fe-N(nitride) 1.877(2) Å, and N(nitride)-Li 1.990(6) Å. A similar 2e(-) reduction of 1,2-diphenylhydrazine by ((tbs)L)Fe3(thf) affords ((tbs)L)Fe3(?(3)-NPh) and aniline. The solid state structure of ((tbs)L)Fe3(?(3)-NPh) is similar to the series of ?(3)-nitrido and -imido triiron complexes synthesized in this work with average Fe-Nimido and Fe-Fe bond lengths of 1.941(6) and 2.530(1) Å, respectively. Reductive N?N bond cleavage of azobenzene is also achieved in the presence of ((tbs)L)Fe3(thf) to yield triiron bis-imido complex ((tbs)L)Fe3(?(3)-NPh)(?(2)-NPh), which has been structurally characterized. Ligand redox participation has been ruled out, and therefore, charge balance indicates that the bis-imido cluster has undergone a 4e(-) metal based oxidation resulting in an (Fe(IV))(Fe(III))2 formulation. Cyclic voltammograms of the series of triiron clusters presented herein demonstrate that oxidation states up to (Fe(IV))(Fe(III))2 (in the case of [((tbs)L)Fe3(?(3)-N)]NBu4) are electrochemically accessible. These results highlight the efficacy of high-spin, polynuclear reaction sites to cooperatively mediate small molecule activation."],"journal":["Journal of the American Chemical Society"],"pubmed_title":["Testing the polynuclear hypothesis: multielectron reduction of small molecules by triiron reaction sites."],"pmcid":["PMC3801182"],"funding_grant_id":["GM 098395","R01 GM098395"],"pubmed_authors":["Powers TM","Betley TA"],"additional_accession":[]},"is_claimable":false,"name":"Testing the polynuclear hypothesis: multielectron reduction of small molecules by triiron reaction sites.","description":"High-spin trinuclear iron complex ((tbs)L)Fe3(thf) ([(tbs)L](6-) = [1,3,5-C6H9(NC6H4-o-NSi(t)BuMe2)3](6-)) (S = 6) facilitates 2 and 4e(-) reduction of NxHy type substrates to yield imido and nitrido products. Reaction of hydrazine or phenylhydrazine with ((tbs)L)Fe3(thf) yields triiron ?(3)-imido cluster ((tbs)L)Fe3(?(3)-NH) and ammonia or aniline, respectively. ((tbs)L)Fe3(?(3)-NH) has a similar zero-field (57)Fe Mössbauer spectrum compared to previously reported [((tbs)L)Fe3(?(3)-N)]NBu4, and can be directly synthesized by protonation of the anionic triiron nitrido with lutidinium tetraphenylborate. Deprotonation of the triiron parent imido ((tbs)L)Fe3(?(3)-NH) with lithium bis(trimethylsilyl)amide results in regeneration of the triiron nitrido complex capped with a thf-solvated Li cation [((tbs)L)Fe3(?(3)-N)]Li(thf)3. The lithium capped nitrido, structurally similar to the pseudo C3-symmetric triiron nitride with a tetrabutylammonium countercation, is rigorously C3-symmetric featuring intracore distances of Fe-Fe 2.4802(5) Å, Fe-N(nitride) 1.877(2) Å, and N(nitride)-Li 1.990(6) Å. A similar 2e(-) reduction of 1,2-diphenylhydrazine by ((tbs)L)Fe3(thf) affords ((tbs)L)Fe3(?(3)-NPh) and aniline. The solid state structure of ((tbs)L)Fe3(?(3)-NPh) is similar to the series of ?(3)-nitrido and -imido triiron complexes synthesized in this work with average Fe-Nimido and Fe-Fe bond lengths of 1.941(6) and 2.530(1) Å, respectively. Reductive N?N bond cleavage of azobenzene is also achieved in the presence of ((tbs)L)Fe3(thf) to yield triiron bis-imido complex ((tbs)L)Fe3(?(3)-NPh)(?(2)-NPh), which has been structurally characterized. Ligand redox participation has been ruled out, and therefore, charge balance indicates that the bis-imido cluster has undergone a 4e(-) metal based oxidation resulting in an (Fe(IV))(Fe(III))2 formulation. Cyclic voltammograms of the series of triiron clusters presented herein demonstrate that oxidation states up to (Fe(IV))(Fe(III))2 (in the case of [((tbs)L)Fe3(?(3)-N)]NBu4) are electrochemically accessible. These results highlight the efficacy of high-spin, polynuclear reaction sites to cooperatively mediate small molecule activation.","dates":{"release":"2013-01-01T00:00:00Z","publication":"2013 Aug","modification":"2020-10-29T09:59:57Z","creation":"2019-03-27T01:17:24Z"},"accession":"S-EPMC3801182","cross_references":{"pubmed":["23865953"],"doi":["10.1021/ja405057n"]}}