Tuning the structure and magnetic properties via distinct pyridine derivatives in cobalt(ii) coordination polymers

Shao, Dong and Moorthy, Shruti and Yang, Xiaodong and Yang, Jiong and Shi, Le and Singh, Saurabh Kumar and et al, . (2022) Tuning the structure and magnetic properties via distinct pyridine derivatives in cobalt(ii) coordination polymers. Dalton Transactions, 51 (2). pp. 695-704. ISSN 1477-9226

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Abstract

Precise modulation of the structure and magnetic properties of coordination compounds is of great importance in the development of framework magnetic materials. Herein, we report that the coordination self-assembly of a neutral cobalt(ii) magnetic building block and selective pyridine derivatives as organic linkers has led to two distinct cobalt(ii) coordination polymers, {Co(DClQ)2(bpy)}n (1) and {Co2(DClQ)4(tpb)}n (2) (DClQ = (5,7-dichloro-8-hydroxyquinoline; bpy = 4, 4′-dipyridine; tpb = 1,2,4,5-tetra(4-pyridyl)benzene)). Structural analyses revealed that 1 and 2 are one-dimensional (1D) and 2D coordination polymers containing the same neutral magnetic building block [Co(DClQ)2] bridged by bitopic bpy and tetratopic tpb ligands, respectively. Both the complexes have a distorted octahedral CoN4O2 coordination geometry around each cobalt center offered by the bidentate ligand and organic linkers. Magnetic studies reveal large easy-plane and easy-axis magnetic anisotropy for 1 and 2, respectively. However, because of the weak antiferromagnetic coupling between the bpy-bridged CoII centers, no slow relaxation of the magnetization was observed in 1 under both zero or applied dc fields. Interestingly, complex 2 exhibits slow magnetic relaxation under external fields, indicative of a framework single-ion magnet of 2. Theoretical calculations further support the experimental results and unveil that the D values are +65.3 and -91.2 cm-1 for 1 and 2, respectively, while the magnetic exchange interaction was precisely estimated as -0.16 (1) and -0.009 (2) cm-1. The foregoing results show that the structural dimensionality and magnetic properties can be rationally modified via pre-designed magnetic building blocks and a suitable choice of organic bridging ligands. This journal is © The Royal Society of Chemistry.

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IITH Creators:

IITH Creators	ORCiD
Singh, Saurabh Kumar	UNSPECIFIED

Item Type:

Article

Additional Information:

This work was supported by a start-up fund from Huanggang Normal University (no. 2042021033). SM is thankful for the Prime Minister Research Fellowship. SKS acknowledges the Department of Science and Technology for the Start-up Research Grant (SRG/2020/001323) and IIT Hyderabad for generous funding. The support and resources provided by PARAM Shivay Facility under the National Supercomputing Mission, Government of India at the Indian Institute of Technology, Varanasi, are gratefully acknowledged. We thank Prof. Yuan-Zhu Zhang from Southern University of Science and Technology (SUSTech) for the use of his SQUID VSM magnetometer.

Uncontrolled Keywords:

8-Hydroxyquinoline; Building blockes; Coordination compounds; Coordination Polymers; Coordination-polymers; Dipyridine; One-dimensional; Organic linkers; Pyridine derivatives; Pyridyl

Subjects:

Chemistry
Chemical Engineering

Divisions:

Department of Chemistry

Depositing User:

. LibTrainee 2021

Date Deposited:

15 Jul 2022 07:15

Last Modified:

15 Jul 2022 07:15

URI:

http://raiithold.iith.ac.in/id/eprint/9730