83095-81-2Relevant articles and documents
Syntheses, ground electronic state, and crystal and molecular structure of the monomeric manganese(IV) porphyrin complex dimethoxy(5,10,15,20-tetraphenylporphinato)manganese(IV)
Camenzind, Mark J.,Hollander, Frederick J.,Hill, Craig L.
, p. 4301 - 4308 (2008/10/08)
The complex dimethoxy(5,10,15,20-tetraphenylporphinato)manganese(IV), MnIVTPP(OCH3)2, Mn(C44H28N4)(OCH3)2, has been synthesized by the oxidation of MnIIITPP(OAc) in basic methanol using either sodium hypochlorite or iodosylbenzene as oxidants. The crystal and molecular structure has been determined by X-ray crystallographic methods. The compound crystallized as a partial methanol solvate, MnIVTPP(OCH3)2·1/4CH3OH, in space group P42/n, with cell dimensions a = 19.388 (2) A?, c = 9.779 (1) A?, Vcalcd = 3676 (1) A?3, and Z = 4. The structure was solved by the heavy-atom method and was refined by full-matrix least-squares techniques to a final value of R = 0.0417 (Rw = 0.0545) based upon 1395 observations. The Mn atom is located at a crystallographic inversion center and is six-coordinate with the O-Mn-O unit linear and the MnN4 unit strictly planar. Bond distances are as follows: two Mn-O bonds, 1.839 (2) A?; two Mn-N1 bonds, 1.993 (3) A?; two Mn-N2 bonds, 2.031 (3) A?; two O-C bonds, 1.387 (3) A?. The magnetic susceptibility of MnIVTPP(OCH3)2 determined in solution and in the solid state at 25°C gave μeff = 3.9 μB. Low-temperature magnetic susceptibility measurements of the solid complex showed Curie-Weiss behavior with θ = -0.5 K and μeff = 3.91 ± 0.02 μB from 5.0 to 300 K. A high-spin d3 manganese(IV) porphyrin ground electronic state is assigned to MnIVTPP(OCH3)2 on the basis of structural, magnetic, and infrared spectral properties. The oxidation of MnIITPP by iodosylbenzene in methanol is also found to yield MnIVTPP(OCH3)2, in contrast to a previous report of the synthesis of O=MnIVTPP under similar conditions.
