Full metadata record
DC Field | Value | Language |
---|---|---|
dc.contributor.author | 남원우 | * |
dc.contributor.author | 이용민 | * |
dc.date.accessioned | 2016-08-28T10:08:30Z | - |
dc.date.available | 2016-08-28T10:08:30Z | - |
dc.date.issued | 2012 | * |
dc.identifier.issn | 0002-7863 | * |
dc.identifier.other | OAK-9016 | * |
dc.identifier.uri | https://dspace.ewha.ac.kr/handle/2015.oak/222845 | - |
dc.description.abstract | [Fe IV=O(TBC)(CH 3CN)] 2+ (TBC = 1,4,8,11-tetrabenzyl-1,4,8,11-tetraazacyclotetradecane) is characterized, and its reactivity differences relative to [Fe IV=O(TMC)(CH 3CN)] 2+ (TMC = 1,4,8,11-tetramethyl-1,4,8,11- tetraazacyclotetradecane) are evaluated in hydrogen atom (H-atom) abstraction and oxo-transfer reactions. Structural differences are defined using X-ray absorption spectroscopy and correlated to reactivities using density functional theory. The S = 1 ground states are highly similar and result in large activation barriers (∼25 kcal/mol) due to steric interactions between the cyclam chelate and the substrate (e.g., ethylbenzene) associated with the equatorial π-attack required by this spin state. Conversely, H-atom abstraction reactivity on an S = 2 surface allows for a σ-attack with an axial substrate approach. This results in decreased steric interactions with the cyclam and a lower barrier (∼9 kcal/mol). For [Fe IV=O(TBC) (CH 3CN)] 2+, the S = 2 excited state in the reactant is lower in energy and therefore more accessible at the transition state due to a weaker ligand field associated with the steric interactions of the benzyl substituents with the trans-axial ligand. This study is further extended to the oxo-transfer reaction, which is a two-electron process requiring both σ- and π-electron transfer and thus a nonlinear transition state. In oxo-transfer, the S = 2 has a lower barrier due to sequential vs concerted (S = 1) two electron transfer which gives a high-spin ferric intermediate at the transition state. The [Fe IV=O(TBC)(CH 3CN)] 2+ complex is more distorted at the transition state, with the iron farther out of the equatorial plane due to the steric interaction of the benzyl groups with the trans-axial ligand. This allows for better orbital overlap with the substrate, a lower barrier, and an increased rate of oxo-transfer. © 2012 American Chemical Society. | * |
dc.language | English | * |
dc.title | [Fe IV=O(TBC)(CH 3CN)] 2+: Comparative reactivity of iron(IV)-oxo species with constrained equatorial cyclam ligation | * |
dc.type | Article | * |
dc.relation.issue | 28 | * |
dc.relation.volume | 134 | * |
dc.relation.index | SCI | * |
dc.relation.index | SCIE | * |
dc.relation.index | SCOPUS | * |
dc.relation.startpage | 11791 | * |
dc.relation.lastpage | 11806 | * |
dc.relation.journaltitle | Journal of the American Chemical Society | * |
dc.identifier.doi | 10.1021/ja3046298 | * |
dc.identifier.wosid | WOS:000306457900072 | * |
dc.identifier.scopusid | 2-s2.0-84863946732 | * |
dc.author.google | Wilson S.A. | * |
dc.author.google | Chen J. | * |
dc.author.google | Hong S. | * |
dc.author.google | Lee Y.-M. | * |
dc.author.google | Clemancey M. | * |
dc.author.google | Garcia-Serres R. | * |
dc.author.google | Nomura T. | * |
dc.author.google | Ogura T. | * |
dc.author.google | Latour J.-M. | * |
dc.author.google | Hedman B. | * |
dc.author.google | Hodgson K.O. | * |
dc.author.google | Nam W. | * |
dc.author.google | Solomon E.I. | * |
dc.contributor.scopusid | 남원우(7006569723) | * |
dc.contributor.scopusid | 이용민(36546331100;35233855500;57192113229) | * |
dc.date.modifydate | 20240130092654 | * |