Structural and Magnetic Analysis of a Family of Structurally Related Iron(III)-Oxo Clusters of Metal Nuclearity Fe8, Fe12Ca4, and Fe12La4 †

Alok P. Singh; Christi Anna L. Brantley; Kenneth Hong Kit Lee; Khalil A. Abboud; Juan E. Peralta; George Christou

doi:10.3390/chemistry5030110

Structural and Magnetic Analysis of a Family of Structurally Related Iron(III)-Oxo Clusters of Metal Nuclearity Fe₈, Fe₁₂Ca₄, and Fe₁₂La₄ †

Alok P. Singh, Christi Anna L. Brantley, Kenneth Hong Kit Lee, Khalil A. Abboud, Juan E. Peralta, George Christou

Research output: Contribution to journal › Article › peer-review

Abstract

The synthesis, crystal structure, and magnetic characterization are reported for three new structurally related iron(III) compounds (NHEt₃)[Fe₈O₅(OH)₅(O₂PPh₂)₁₀] (1), [Fe₁₂ Ca₄O₁₀(O₂CPh)₁₀(hmp)₄] (2), and [Fe₁₂La₄O₁₀(OH)₄(tbb)₂₄] (3), where hmpH is 2-(hydroxymethyl)pyridine and tbbH is 4-^tBu-benzoic acid. 1 was obtained from the reaction of Fe(NO₃)₃·9H₂O, diphenylphosphinic acid (Ph₂PO₂H), and NEt₃ in a 1:4:16 molar ratio in MeCN at 50 °C; 2 was obtained from the reaction of [Fe₃O(O₂CPh)₆(H₂O)₃](NO₃), Ca(NO₃)₂, and NEt₃ in a 1:1:4:2 ratio at 130 °C; and 3 was obtained from the reaction of Fe(NO₃)₃·9H₂O, La(NO₃)₃·6H₂O, 4-^tBu-benzoic acid, and NEt₃ in a 1:1:4:4 ratio in PhCN at 140 °C. The core of 1 consists of two {Fe₄(µ₃-O)₂}⁸⁺ butterfly units stacked on top of each other and bridged by O²⁻ and HO⁻ ions. The cores of 2 and 3 also contain two stacked butterfly units, plus four additional Fe atoms, two at each end, and four M atoms (M = Ca²⁺ (2); La³⁺ (3)) on the sides. Variable-temperature (T) and solid-state dc and ac magnetization (M) data collected in the 1.8–300 K range revealed that 1 has an S = 0 ground state, 2 has a χ_MT value at low T consistent with the central Fe₈ in a local S = 0 ground state and the two Fe³⁺ ions in each end-pair to be non-interacting, whereas 3 has a χ_MT value at low T consistent with these end-pairs each being ferromagnetically coupled with S = 5 ground states, plus intermolecular ferromagnetic interactions. These conclusions were reached from complementing the experimental studies with the calculation of the various Fe₂ pairwise J_ij exchange couplings by DFT computations and by using a magnetostructural correlation (MSC) for polynuclear Fe³⁺/O complexes, as well as a structural analysis of the intermolecular contacts in the crystal packing of 3.

Original language	English
Pages (from-to)	1599-1620
Number of pages	22
Journal	Chemistry (Switzerland)
Volume	5
Issue number	3
DOIs	https://doi.org/10.3390/chemistry5030110
State	Published - Sep 2023
Externally published	Yes

Funding

This work was supported by the U.S. National Science Foundation (Grant CHE-1900321), and by the Department of Energy, Office of Science, Office of Basic Energy Sciences, as part of the Computational Chemical Sciences Program under Award #DE-SC0018331. We thank the U.S. National Science Foundation for funding of the X-ray diffractometer at the University of Florida through grant CHE-1828064.

Keywords

density functional theory
exchange interactions
iron-oxo clusters
magnetostructural correlation
molecular magnetism
pseudo-carboxylates

Access to Document

10.3390/chemistry5030110

Cite this

@article{cac42700328b4d4d991d7484b4357b96,

title = "Structural and Magnetic Analysis of a Family of Structurally Related Iron(III)-Oxo Clusters of Metal Nuclearity Fe8, Fe12Ca4, and Fe12La4 †",

abstract = "The synthesis, crystal structure, and magnetic characterization are reported for three new structurally related iron(III) compounds (NHEt3)[Fe8O5(OH)5(O2PPh2)10] (1), [Fe12 Ca4O10(O2CPh)10(hmp)4] (2), and [Fe12La4O10(OH)4(tbb)24] (3), where hmpH is 2-(hydroxymethyl)pyridine and tbbH is 4-tBu-benzoic acid. 1 was obtained from the reaction of Fe(NO3)3·9H2O, diphenylphosphinic acid (Ph2PO2H), and NEt3 in a 1:4:16 molar ratio in MeCN at 50 °C; 2 was obtained from the reaction of [Fe3O(O2CPh)6(H2O)3](NO3), Ca(NO3)2, and NEt3 in a 1:1:4:2 ratio at 130 °C; and 3 was obtained from the reaction of Fe(NO3)3·9H2O, La(NO3)3·6H2O, 4-tBu-benzoic acid, and NEt3 in a 1:1:4:4 ratio in PhCN at 140 °C. The core of 1 consists of two \{Fe4(µ3-O)2\}8+ butterfly units stacked on top of each other and bridged by O2− and HO− ions. The cores of 2 and 3 also contain two stacked butterfly units, plus four additional Fe atoms, two at each end, and four M atoms (M = Ca2+ (2); La3+ (3)) on the sides. Variable-temperature (T) and solid-state dc and ac magnetization (M) data collected in the 1.8–300 K range revealed that 1 has an S = 0 ground state, 2 has a χMT value at low T consistent with the central Fe8 in a local S = 0 ground state and the two Fe3+ ions in each end-pair to be non-interacting, whereas 3 has a χMT value at low T consistent with these end-pairs each being ferromagnetically coupled with S = 5 ground states, plus intermolecular ferromagnetic interactions. These conclusions were reached from complementing the experimental studies with the calculation of the various Fe2 pairwise Jij exchange couplings by DFT computations and by using a magnetostructural correlation (MSC) for polynuclear Fe3+/O complexes, as well as a structural analysis of the intermolecular contacts in the crystal packing of 3.",

keywords = "density functional theory, exchange interactions, iron-oxo clusters, magnetostructural correlation, molecular magnetism, pseudo-carboxylates",

author = "Singh, \{Alok P.\} and Brantley, \{Christi Anna L.\} and Lee, \{Kenneth Hong Kit\} and Abboud, \{Khalil A.\} and Peralta, \{Juan E.\} and George Christou",

note = "Publisher Copyright: {\textcopyright} 2023 by the authors.",

year = "2023",

month = sep,

doi = "10.3390/chemistry5030110",

language = "English",

volume = "5",

pages = "1599--1620",

journal = "Chemistry (Switzerland)",

issn = "2624-8549",

publisher = "MDPI",

number = "3",

}

TY - JOUR

T1 - Structural and Magnetic Analysis of a Family of Structurally Related Iron(III)-Oxo Clusters of Metal Nuclearity Fe8, Fe12Ca4, and Fe12La4 †

AU - Singh, Alok P.

AU - Brantley, Christi Anna L.

AU - Lee, Kenneth Hong Kit

AU - Abboud, Khalil A.

AU - Peralta, Juan E.

AU - Christou, George

PY - 2023/9

Y1 - 2023/9

N2 - The synthesis, crystal structure, and magnetic characterization are reported for three new structurally related iron(III) compounds (NHEt3)[Fe8O5(OH)5(O2PPh2)10] (1), [Fe12 Ca4O10(O2CPh)10(hmp)4] (2), and [Fe12La4O10(OH)4(tbb)24] (3), where hmpH is 2-(hydroxymethyl)pyridine and tbbH is 4-tBu-benzoic acid. 1 was obtained from the reaction of Fe(NO3)3·9H2O, diphenylphosphinic acid (Ph2PO2H), and NEt3 in a 1:4:16 molar ratio in MeCN at 50 °C; 2 was obtained from the reaction of [Fe3O(O2CPh)6(H2O)3](NO3), Ca(NO3)2, and NEt3 in a 1:1:4:2 ratio at 130 °C; and 3 was obtained from the reaction of Fe(NO3)3·9H2O, La(NO3)3·6H2O, 4-tBu-benzoic acid, and NEt3 in a 1:1:4:4 ratio in PhCN at 140 °C. The core of 1 consists of two {Fe4(µ3-O)2}8+ butterfly units stacked on top of each other and bridged by O2− and HO− ions. The cores of 2 and 3 also contain two stacked butterfly units, plus four additional Fe atoms, two at each end, and four M atoms (M = Ca2+ (2); La3+ (3)) on the sides. Variable-temperature (T) and solid-state dc and ac magnetization (M) data collected in the 1.8–300 K range revealed that 1 has an S = 0 ground state, 2 has a χMT value at low T consistent with the central Fe8 in a local S = 0 ground state and the two Fe3+ ions in each end-pair to be non-interacting, whereas 3 has a χMT value at low T consistent with these end-pairs each being ferromagnetically coupled with S = 5 ground states, plus intermolecular ferromagnetic interactions. These conclusions were reached from complementing the experimental studies with the calculation of the various Fe2 pairwise Jij exchange couplings by DFT computations and by using a magnetostructural correlation (MSC) for polynuclear Fe3+/O complexes, as well as a structural analysis of the intermolecular contacts in the crystal packing of 3.

AB - The synthesis, crystal structure, and magnetic characterization are reported for three new structurally related iron(III) compounds (NHEt3)[Fe8O5(OH)5(O2PPh2)10] (1), [Fe12 Ca4O10(O2CPh)10(hmp)4] (2), and [Fe12La4O10(OH)4(tbb)24] (3), where hmpH is 2-(hydroxymethyl)pyridine and tbbH is 4-tBu-benzoic acid. 1 was obtained from the reaction of Fe(NO3)3·9H2O, diphenylphosphinic acid (Ph2PO2H), and NEt3 in a 1:4:16 molar ratio in MeCN at 50 °C; 2 was obtained from the reaction of [Fe3O(O2CPh)6(H2O)3](NO3), Ca(NO3)2, and NEt3 in a 1:1:4:2 ratio at 130 °C; and 3 was obtained from the reaction of Fe(NO3)3·9H2O, La(NO3)3·6H2O, 4-tBu-benzoic acid, and NEt3 in a 1:1:4:4 ratio in PhCN at 140 °C. The core of 1 consists of two {Fe4(µ3-O)2}8+ butterfly units stacked on top of each other and bridged by O2− and HO− ions. The cores of 2 and 3 also contain two stacked butterfly units, plus four additional Fe atoms, two at each end, and four M atoms (M = Ca2+ (2); La3+ (3)) on the sides. Variable-temperature (T) and solid-state dc and ac magnetization (M) data collected in the 1.8–300 K range revealed that 1 has an S = 0 ground state, 2 has a χMT value at low T consistent with the central Fe8 in a local S = 0 ground state and the two Fe3+ ions in each end-pair to be non-interacting, whereas 3 has a χMT value at low T consistent with these end-pairs each being ferromagnetically coupled with S = 5 ground states, plus intermolecular ferromagnetic interactions. These conclusions were reached from complementing the experimental studies with the calculation of the various Fe2 pairwise Jij exchange couplings by DFT computations and by using a magnetostructural correlation (MSC) for polynuclear Fe3+/O complexes, as well as a structural analysis of the intermolecular contacts in the crystal packing of 3.

KW - density functional theory

KW - exchange interactions

KW - iron-oxo clusters

KW - magnetostructural correlation

KW - molecular magnetism

KW - pseudo-carboxylates

UR - https://www.scopus.com/pages/publications/85172080241

U2 - 10.3390/chemistry5030110

DO - 10.3390/chemistry5030110

M3 - Article

AN - SCOPUS:85172080241

SN - 2624-8549

VL - 5

SP - 1599

EP - 1620

JO - Chemistry (Switzerland)

JF - Chemistry (Switzerland)

IS - 3

ER -