Synthesis, Structural, Magnetic and Computational Studies of a One-Dimensional Ferromagnetic Cu(II) Chain Assembled from a New Schiff Base Ligand

Authors

Anne Worrell, Brock University
Gabriele Delle Monache, Brock University
Mark M. Turnbull, Clark UniversityFollow
Jeremy M. Rawson, University of Windsor
Theocharis C. Stamatatos, University of Patras
Melanie Pilkington, Brock University

Document Type

Article

Abstract

A new asymmetrically substituted ONOO Schiff base ligand N-(2′-hydroxy-1′-naphthylidene)-3-amino-2-naphthoic acid (nancH₂) was prepared from the condensation of 2–hydroxy–1–naphthaldehyde and 3–amino–2–naphthoic acid. nancH₂ reacts with Cu₂(O₂CMe)₄·2H₂O in the presence of Gd(O₂CMe)₃·6H₂O to afford a uniform one-dimensional homometallic chain, [Cu^II(nanc)]_n (1). The structure of 1 was elucidated via single crystal X-ray diffraction studies, which revealed that the Cu(II) ions adopt distorted square planar geometries and are coordinated in a tridentate manner by an [ONO] donor set from one nanc²⁻ ligand and an O⁻ of a bridging carboxylate group from a second ligand. The bridging carboxylato group of the nanc²⁻ ligand adopts a syn, anti-η¹:η¹:μ conformation linking neighboring Cu(II) ions, forming a 1D chain. The magnetic susceptibility of 1 follows Curie–Weiss law in the range 45–300 K (C = 0.474(1) emu K mol-1, θ = +7.9(3) K), consistent with ferromagnetic interactions between S = ½ Cu(II) ions with g = 2.248. Subsequently, the data fit well to the 1D quantum Heisenberg ferromagnetic (QHFM) chain model with g = 2.271, and J = +12.3 K. DFT calculations, implementing the broken symmetry approach, were also carried out on a model dimeric unit extracted from the polymeric chain structure. The calculated exchange coupling via the carboxylate bridge (J = +13.8 K) is consistent with the observed ferromagnetic exchange between neighbouring Cu(II) centres. © 2023 by the authors.

This article belongs to the Special Issue Coordination Chemistry: Current Developments and Future Perspectives — a Themed Issue in Honor of Professor Spyros P. Perlepes on the Occasion of His 70th Birthday)

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Publication Title

Chemistry (Switzerland)

Publication Date

3-2023

Volume

5

Issue

1

First Page

85

Last Page

91

ISSN

2624-8549

DOI

10.3390/chemistry5010007

Keywords

aromatic ligands, coordination polymer, Cu(II); DFT studies, ferromagnetic interactions, one-dimensional uniform chain, Schiff base

Repository Citation

Worrell, Anne; Delle Monache, Gabriele; Turnbull, Mark M.; Rawson, Jeremy M.; Stamatatos, Theocharis C.; and Pilkington, Melanie, "Synthesis, Structural, Magnetic and Computational Studies of a One-Dimensional Ferromagnetic Cu(II) Chain Assembled from a New Schiff Base Ligand" (2023). Chemistry. 9.
https://commons.clarku.edu/chemistry/9

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Copyright Conditions

Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/4.0/).