TY - JOUR
T1 - Magnetic Properties of High-Nuclearity Fex-oxo (x = 7, 22, 24) Clusters Analyzed by a Multipronged Experimental, Computational, and Magnetostructural Correlation Approach
AU - Hale, Ashlyn R.
AU - Lott, Megan E.
AU - Peralta, Juan E.
AU - Foguet-Albiol, Dolos
AU - Abboud, Khalil A.
AU - Christou, George
N1 - Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
PY - 2022/7/25
Y1 - 2022/7/25
N2 - The synthesis, structure, and magnetic properties of three related iron(III)-oxo clusters are reported, [Fe7O3(O2CPh)9(mda)3(H2O)] (1), [Fe22O14(OH)3(O2CMe)21(mda)6](ClO4)2(2), and [Fe24O15(OH)4(OEt)(O2CMe)21(mda)7](ClO4)2(3), where mdaH2is N-methyldiethanolamine. 1 was prepared from the reaction of [Fe3O(O2CPh)6(H2O)3](NO3) with mdaH2in a 1:2 ratio in MeCN, whereas 2 and 3 were prepared from the reaction of FeCl3/NaO2CMe/mdaH2in a 2:â 13:2 ratio and FeCl3/NaO2CMe/mdaH2/pyridine in a 2:â 13:2:25 ratio, respectively, both in EtOH. The core of 1 consists of a central octahedral FeIIIion held within a nonplanar Fe6loop by three μ3-O2-and three μ2-RO-arms from the three mda2-chelates. The cores of the cations of 2 and 3 consist of an A:B:A three-layer topology, in which a central Fe6(2) or Fe8(3) layer B is sandwiched between two Fe8layers A. The A layers structurally resemble 1 with the additional Fe added at the center to retain virtual C3symmetry. The central Fe6layer B of 2 consists of a {Fe4(μ4-O)2(μ3-OH)2}6+cubane with an Fe on either side attached to cubane O2-ions, whereas that of 3 has the same cubane but with an {Fe3(μ3-O)(μ-OH)} unit attached on one side and a single Fe on the other. Variable-Temperature dc and ac magnetic susceptibility studies revealed dominant antiferromagnetic coupling in all complexes leading to ground-state spins of S = 5/2for 1 and S = 0 for 2 and 3. All Fe2pairwise exchange parameters (Jij) for 1-3 were estimated by two independent methods: density functional theory (DFT) calculations using broken symmetry methods and a magnetostructural correlation previously developed for high-nuclearity FeIII/O complexes. The two approaches gave satisfyingly similar Jijvalues, and the latter allowed rationalization of the experimental ground states by identification of the spin frustration effects operative and the resultant relative spin vector alignments at each FeIIIion.
AB - The synthesis, structure, and magnetic properties of three related iron(III)-oxo clusters are reported, [Fe7O3(O2CPh)9(mda)3(H2O)] (1), [Fe22O14(OH)3(O2CMe)21(mda)6](ClO4)2(2), and [Fe24O15(OH)4(OEt)(O2CMe)21(mda)7](ClO4)2(3), where mdaH2is N-methyldiethanolamine. 1 was prepared from the reaction of [Fe3O(O2CPh)6(H2O)3](NO3) with mdaH2in a 1:2 ratio in MeCN, whereas 2 and 3 were prepared from the reaction of FeCl3/NaO2CMe/mdaH2in a 2:â 13:2 ratio and FeCl3/NaO2CMe/mdaH2/pyridine in a 2:â 13:2:25 ratio, respectively, both in EtOH. The core of 1 consists of a central octahedral FeIIIion held within a nonplanar Fe6loop by three μ3-O2-and three μ2-RO-arms from the three mda2-chelates. The cores of the cations of 2 and 3 consist of an A:B:A three-layer topology, in which a central Fe6(2) or Fe8(3) layer B is sandwiched between two Fe8layers A. The A layers structurally resemble 1 with the additional Fe added at the center to retain virtual C3symmetry. The central Fe6layer B of 2 consists of a {Fe4(μ4-O)2(μ3-OH)2}6+cubane with an Fe on either side attached to cubane O2-ions, whereas that of 3 has the same cubane but with an {Fe3(μ3-O)(μ-OH)} unit attached on one side and a single Fe on the other. Variable-Temperature dc and ac magnetic susceptibility studies revealed dominant antiferromagnetic coupling in all complexes leading to ground-state spins of S = 5/2for 1 and S = 0 for 2 and 3. All Fe2pairwise exchange parameters (Jij) for 1-3 were estimated by two independent methods: density functional theory (DFT) calculations using broken symmetry methods and a magnetostructural correlation previously developed for high-nuclearity FeIII/O complexes. The two approaches gave satisfyingly similar Jijvalues, and the latter allowed rationalization of the experimental ground states by identification of the spin frustration effects operative and the resultant relative spin vector alignments at each FeIIIion.
UR - http://www.scopus.com/inward/record.url?scp=85135202502&partnerID=8YFLogxK
U2 - 10.1021/acs.inorgchem.2c01371
DO - 10.1021/acs.inorgchem.2c01371
M3 - Article
C2 - 35816698
AN - SCOPUS:85135202502
SN - 0020-1669
VL - 61
SP - 11261
EP - 11276
JO - Inorganic Chemistry
JF - Inorganic Chemistry
IS - 29
ER -