title: Unusual role of solvents in the syntheses of {Fe-NO}6,7 nitrosyls derived from a ligand with carboxamido nitrogen and thiolato sulfur donors.
abstract: Reaction of excess NO with the S = 3/2 Fe(III) complex (Et4N)2[Fe(PhPepS)(Cl)] (1) in protic solvents such as MeOH affords the {Fe-NO}(7) nitrosyl (Et(4)N)(2)[Fe(PhPepS)(NO)] (2). This distorted square-pyramidal S = 1/2 complex, a product of reductive nitrosylation, is the first example of an {Fe-NO}7 nitrosyl with carboxamido-N and thiolato-S coordination. When the same reaction is performed in aprotic solvents such as MeCN and DMF, the product is a dimeric diamagnetic {Fe-NO}6 complex, (Et4N)2-[{Fe(PhPepS)(NO)}2] (3). Both electrochemical and chemical oxidation of 2 leads to the formation of 3 via a transient five-coordinate {Fe-NO}6 intermediate. The oxidation is NO-centered. The ligand frame is not attacked by excess NO in these reactions.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Santa Cruz, 95064, USA.
authors.forename: Todd C
authors.initials: TC
authors.lastname: Harrop
authors.forename: Marilyn M
authors.initials: MM
authors.lastname: Olmstead
authors.forename: Pradip K
authors.initials: PK
authors.lastname: Mascharak
mesh_terms: D000577:Amides; D005290:Ferric Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D008024:Ligands; D008958:Models, Molecular; D009566:Nitrates / Q000138:chemical synthesis* / Q000737:chemistry; D009584:Nitrogen; D009589:Nitrogen Oxides / Q000737:chemistry*; D012997:Solvents; D013438:Sulfhydryl Compounds; D013455:Sulfur
chemical_list: D000577:Amides; D005290:Ferric Compounds; D008024:Ligands; D009566:Nitrates; D009589:Nitrogen Oxides; D012997:Solvents; D013438:Sulfhydryl Compounds; D013455:Sulfur; D009584:Nitrogen; C025302:ferric nitrate