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Updated: Jul 11, 2025
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Semiempirical Magnetostructural Correlation for High-Nuclearity MnIII-Oxo Complexes: Accommodation of Different
Kenneth Hong Kit Lee1, George Christou1
1Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, United States.
Abstract:
The previous development of a magnetostructural correlation (MSC) for polynuclear FeIII/oxo clusters has now been extended to one for polynuclear MnIII/oxo clusters. A semiempirical model estimating each pairwise Mn2 exchange constant (J) from the Mn-O bond lengths and Mn-O-Mn angles has been formulated based on the angular overlap model. The extra complication, compared with the FeIII/oxo MSC, of different relative orientations of the Jahn-Teller distortion axes typical of high-spin MnIII in near-octahedral geometry was accommodated by developing a separate MSC variant for each possible situation. The final coefficients of the three MSC variants were determined by using reliable crystal structure data and experimentally determined J values from the literature. The estimated JMSC values from the new MnIII/oxo MSC have been employed to successfully rationalize the magnetic properties of a number of MnIII clusters in the nuclearity range Mn3-Mn10. These properties include relative spin vector alignments in the ground state, the presence of spin frustration effects, and the resulting overall ground state spin. In addition, the JMSC values can be used to simulate the direct-current magnetic susceptibility versus temperature data and provide realistic input values for fits of these data to minimize false-fit problems. A protocol for the use of the new MSC is also reported.
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