Interplay between anisotropy and magnetic exchange to modulate the magnetic relaxation behaviours of phenoxo bridged Dy2 dimers with axial β-diketonate co-ligands

Roy, Soumalya and Shukla, Pooja and Singh, Saurabh Kumar (2022) Interplay between anisotropy and magnetic exchange to modulate the magnetic relaxation behaviours of phenoxo bridged Dy2 dimers with axial β-diketonate co-ligands. Dalton Transactions, 51 (18187). pp. 1-16. ISSN 1477-9226

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Abstract

A series of Schiff base LH ((E)-2-((pyridin-2-ylmethylene)amino)phenol) supported phenoxo bridged symmetric [Dy2(L)2(hfac)4] (1), [Dy2(L)2(tfac)4] (2) and asymmetric [Dy2(L)2(thd)3(NO3)]·1.5H2O (3) binuclear complexes were isolated using differently substituted β-diketonate co-ligands (Hhfac = hexafluoroacetylacetonate, Htfac = trifluoroacetylacetonate, and Hthd = 2,2,6,6-tetramethyl-3,5-heptanedione). In all the three complexes 1-3, the two LH ligands provide phenoxo bridging and N-donor atoms. The {Dy2(μ2-O)2} magnetic core structures with LH ligands are found to be the same in 1-3 while the dissimilar functionalities of the axially coordinated different β-diketonate co-ligands play a crucial role in modulating the magnetic anisotropy of individual DyIII sites and magnetic exchange between them. The experimental static magnetic behaviour suggests the presence of intramolecular antiferromagnetic interactions in all the three complexes 1-3. The strength of the magnetic exchange coupling decreases with increasing magnetic anisotropy of individual DyIII ions from complex 1 to complex 3 and simultaneously their zero-field slow magnetic relaxation behaviors were found to increase with effective energy barriers (ΔE/kB) of 9.04 K, 24.06 K and 25.65 K, respectively. Furthermore, the DFT and ab initio theoretical calculations performed on the X-ray structures of complexes 1-3 support our experimental findings. © 2022 The Royal Society of Chemistry.

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IITH Creators:

IITH Creators	ORCiD
Singh, Saurabh Kumar	https://orcid.org/0000-0001-9488-8036

Item Type:

Article

Additional Information:

Sourav Das and Pooja Shukla gratefully acknowledge the financial support from the Early Career Research Award, Project File Number ECR/2016/001746, SERB-DST, India. Pooja Shukla would like to thank the Council of Scientific and Industrial Research (CSIR), India, for the Senior Research Fellowship File No. 09/1274(11299)/2021-EMR-I. Soumalya Roy and Pooja Shukla are thankful to IITRAM for providing financial support and for infrastructural facilities. Naushad Ahmed acknowledges SERB-DST India (file no. PDF/2020/000074) for the postdoctoral fellowship. Tulika Gupta acknowledges Prof. Gopalan Rajaraman, IIT Bombay for computational resources and financial support from the UGC (BSR/2019/F.30-470). SKS acknowledges the DST-SERB (SRG/2020/001323) and IIT Hyderabad for the start-up research grant.

Uncontrolled Keywords:

modulate the magnetic relaxation,phenoxo bridged Dy2 ,β-diketonate

Subjects:

Chemistry

Divisions:

Department of Chemistry

Depositing User:

Ms Palak Jain

Date Deposited:

22 May 2023 09:28

Last Modified:

22 May 2023 09:28