105121-85-5Relevant articles and documents
Isolation and characterization of a five-coordinate manganese(III) porphyrin cation. Crystal and molecular structure of aquo(tetraphenylporphinato)manganese(III) triflate
Williamson, Michael M.,Hill, Craig L.
, p. 4668 - 4671 (2008/10/08)
Five-coordinate cationic manganese(III) porphyrin complexes exist in nonpolar organic media in the presence of a limiting amount of water. Slow diffusion of heptane into a benzene solution of (tetraphenylporphinato)manganese(III) triflate containing 1 equiv of water produces crystals of aquo(tetraphenylporphinato)manganese(III) triflate, [(H2O)MnIIITPP]+OTf- (1), the first unequivocal and isolated example of a five-coordinate cationic manganese(III) porphyrin complex. Solvate-free crystals of 1 crystallize in space group P1. The unit cell has a = 11.1735 (47) ?, b = 13.0503 (80) ?, c = 13.8998 (121) ?, α = 81.102 (60)°, β = 79.476 (53)°, γ = 75.312 (41)°, V = 1915.07 (2.17) ?3, and Z = 2. The structure was solved by conventional heavy-atom methods and converged to a final R = 0.0746. Complex 1 has a dMn-O of 2.105 (4) ?, and the Mn atom resides 0.17 and 0.19 ? above the mean 24-atom plane and the mean N4 plane, respectively. The molecular stereochemistry and the electronic spectra for 1 clearly establish the Mn to be in the high spin, S = 2, state. Complex 1 reacts only with a large excess of iodosylbenzene to form one or more high-valent Mn porphyrin species. The five-coordinate cationic form of MnIII porphyrins is accessible under the literature conditions for both the homogeneous catalytic oxygenation of hydrocarbons and the homogeneous oxidation of water by Mn porphyrins.
