Synthesis and structural investigations of [Mn{sub 3}O{sub 4}(phen){sub 4}(H{sub 2}O){sub 2}](NO{sub 3}){sub 4}{lg_bullet}2.5H{sub 2}O: A water-bound complex obtained by cerium(IV) oxidation
- Univ. of Hyderabad (India)
- Univ. of Wyoming, Laramie, WY (United States); and others
The trinuclear manganese complex [Mn{sub 3}O{sub 4}(phen){sub 4}(H{sub 2}O){sub 2}](NO{sub 3}){sub 4}{lg_bullet}2.5H{sub 2}O, 1 (where, phen = 1,10-phenanthroline), has been synthesized by the Ce(IV) oxidation of a concentrated solution of manganese(II) acetate and phen in 1.6 N nitric acid. The complex crystallizes in the triclinic space group P{bar 1} with a = 10.700(2) {angstrom}, b = 12.643(3) {angstrom}, c = 20.509(4) {angstrom}, {alpha} = 78.37(3){degrees}, {beta} = 83.12(3){degrees}, {gamma} = 82.50(3){degrees}, and Z=2. The structure was solved by direct methods and refined by least-squares techniques to the conventional R (R{sub w}) factors of 0.055 (0.076) based on 4609 unique reflections with F{sub o} {ge} 6.0{sigma}(F{sub o}). The structure of the cation consists of an oxo-bridged Mn{sub 3}O{sub 4}{sup 4+} core, with the geometry of the manganese atoms being octahedral. The coordination polyhedron of one of the manganese atoms (Mn(1)) consists of two {mu} oxo ligands and two pairs of nitrogen atoms of two phen moieties, whereas that of each of the remaining two manganese atoms consists of three {mu}-oxo ligands, two nitrogen atoms of a phen moiety, and the oxygen atom of a water molecule. The complex represents the second example for water coordination to manganese (IV) centers in complexes with a Mn{sub 3}O{sub 4}{sup 4+} core. Optical spectra in ligand buffer (pH 4.5) reveal complete conversion of the complex into a Mn{sup III}Mn{sup IV} species. The observed room-temperature (298 K) magnetic moment of 3.75 {mu}{sub B} indicates the presence of strong antiferromagnetic coupling in the complex.
- OSTI ID:
- 379147
- Journal Information:
- Inorganic Chemistry, Vol. 35, Issue 8; Other Information: PBD: 10 Apr 1996
- Country of Publication:
- United States
- Language:
- English
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