Structural and chemical properties of a reactive metalloporphyrin with aliphatic amine N-oxide axial ligands. Crystal and molecular structure of bis(N-methylmorpholine N-oxide)(tetraphenylporphinato)manganese(III) perchlorate

Journal Article · Wed May 20 04:00:00 EDT 1987 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00257a027· OSTI ID:6541469

Brown, Jr, R B; Williamson, M M; Hill, C L

High-spin, S = 2, Mn/sup III/ porphyrin complexes with either strongly or weakly coordinating anionic axial counterions can catalyze the oxygenation of both alkenes and alkanes by aliphatic amine N-oxides at temperatures down to 25/sup 0/C in nonpolar solvents. One particular aliphatic amine N-oxide, N-methylmorpholine N-oxide (MMNO), not only reacts readily with manganese porphyrins to transfer oxygen to both alkenes and alkanes under mild conditions but also forms a reactive yet isolable 2:1 complex with one manganese prophyrin, (tetraphenylporphinato)manganese(III) perchlorate. Conditions have been found under which isolation of the solvate-free oxygen donor-metalloporphyrin complex bis(N-methylmorpholine N-oxide)(tetraphenylporphinato)manganese(III) perchlorate, ((MMNO)/sub 2/Mn/sup III/TPP)/sup +/ClO/sub 4//sup -/, C/sub 54/H/sub 50/ClMnN/sub 6/O/sub 8/ (1), is more rapid than decomposition and hydrocarbon oxidation by this compound. The stoichiometric reactions of 1 with representative alkenes and alkanes are contrasted to catalytic oxygenations of the same substrates using a large excess of the oxygen donor, MMNO, present over the metalloporphyrin. The product distributions for the stoichiometric and catalytic reactions are similar, indicating that the substrate-activating steps and species are similar for both types of processes. Light does not have an effect on the coordination chemistry or oxygen atom transfer chemistry of the ligated N-oxide functions. The electronic absorption and /sup 1/H NMR spectra of 1 clearly indicate that the complex is six-coordinate in solution and contains a S = 2 Mn/sup III/ atom.

• Research Organization: Emory Univ., Atlanta, GA
• OSTI ID: 6541469
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 26:10; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AMINES
CARBOXYLIC ACIDS
CHEMICAL PROPERTIES
CHLORINE COMPOUNDS
COMPLEXES
CRYSTAL STRUCTURE
DATA
EXPERIMENTAL DATA
HALOGEN COMPOUNDS
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INFORMATION
LIGANDS
MANGANESE COMPLEXES
MOLECULAR STRUCTURE
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PERCHLORATES
PORPHYRINS
TRANSITION ELEMENT COMPLEXES