title: A combined experimental and computational study on the sulfoxidation by high-valent iron bispidine complexes.
abstract: Iron-bispidine complexes are efficient catalysts for the oxidation of thioanisole to phenylmethylsulfoxide with iodosylbenzene as oxidant. With the tetradentate bispidine ligand L(1) (L(1) = 2,4-pyridyl-3,7-diazabicyclo[3.3.1]nonane)) the catalytic efficiency is smaller than with the pentadentate bispidine ligand L(2) (L(2) = 2,4-pyridyl-7-(pyridine-2-ylmethyl)-3,7-diazabicyclo[3.3.1]nonane)). Based on the redox potentials (iron complexes with L(1) are stronger oxidants than with L(2)) and known efficiencies in catalytic olefin oxidation and C-H activation reactions, the expectations were different. A DFT-based analysis is used to explain the apparent contradiction, and this is based on differences in the electronic ground states of the ferryl complexes as well as in the oxygen transfer transition states.
authors.affiliation: Universität Heidelberg, Anorganisch-Chemisches Institut, INF 270, D-69120, Heidelberg, Germany.
authors.forename: Madhavan
authors.initials: M
authors.lastname: Jaccob
authors.forename: Peter
authors.initials: P
authors.lastname: Comba
authors.forename: Martin
authors.initials: M
authors.lastname: Maurer
authors.forename: Prabha
authors.initials: P
authors.lastname: Vadivelu
authors.forename: Ponnambalam
authors.initials: P
authors.lastname: Venuvanalingam
mesh_terms: D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D007536:Isomerism; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D011789:Quantum Theory; D012428:Ruthenium / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013440:Sulfides / Q000737:chemistry; D013454:Sulfoxides / Q000737:chemistry*
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D008024:Ligands; D009942:Organometallic Compounds; D013440:Sulfides; D013454:Sulfoxides; C495809:bispidine; D012428:Ruthenium; C093850:methylphenylsulfide; D007501:Iron