Exchange-driven slow relaxation of magnetization in NiII2LnIII2 (LnIII = Y, Gd, Tb and Dy) butterfly complexes: experimental and theoretical studies

Chakraborty, Amit and Ahmed, Naushad and Ali, Junaid and Moorthy, Shruti and Goura, Joydeb and Singh, Saurabh Kumar and et al, . (2022) Exchange-driven slow relaxation of magnetization in NiII2LnIII2 (LnIII = Y, Gd, Tb and Dy) butterfly complexes: experimental and theoretical studies. Dalton Transactions. ISSN 1477-9226

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Abstract

The tetranuclear Ni(2)(II)Ln(2)(III) complexes, [{L'(2){Ni(MeOH)(mu-OAc)}2(mu(3)- MeO)(2)Ln(2)}, Ln(III) = Y-III (1), Gd-III (2), Tb-III (3), and Dy-III (4)], were prepared using a Schiff base ligand, H3L [H3L = 3-{(2-hydroxy-3-methoxybenzylidene)amino}-2-(2-hydroxy- 3-methoxyphenyl)-2,3-dihydroquinazolin-4(1H)-one, where {L'}(3-) is the deprotonated open structure of H3L]. X-ray crystallographic analysis of 1-4 revealed that all the complexes crystallized in the orthorhombic (Pbcn) space group, and possessed an isostructural tetranuclear butterfly or defect dicubane like core. Direct current magnetic susceptibility measurements performed on 2-4 revealed that all these complexes show an intramolecular ferromagnetic exchange coupling. Well resolved zero-field out-of-phase signals in ac magnetic susceptibility measurements were observed only in the case of 3 (U-eff = 13.4 K; tau(0) = 4.1(7) x 10(-7) s). This was attributed to the comparatively strong Ni-II-Tb-III magnetic exchange coupling. DFT and ab initio calculations were carried out on 1-4 to ascertain the nature of the ferromagnetic Ni-II-Ln(III) (J(Ni-Ln)) and Ln(III)-Ln(III) (J(Ln-Ln)) interactions. Magnetic anisotropy and magnetic relaxation mechanisms were discussed in detail for 3 and 4. Theoretical studies provide a rationale for the slow relaxation of magnetization in 3.

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IITH Creators:

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

Item Type:

Article

Additional Information:

V. C. is thankful to the Department of Science and Technology, New Delhi, India, for a National J. C. Bose Fellowship. A. C. is thankful to the Department of Atomic Energy, India for post-doctoral fellowships and University Grants Commission, India (CH/20-21/0252) for the D. S. Kothari Post-Doctoral Fellowship. N. A. is thankful to the Tata Institute of Fundamental Research, Hyderabad for a post-doctoral fellowship. G. R. acknowledges the Labex NIE (ANR-11-LABX-0058_NIE within the Investissement d'Avenir French program ANR-10-IDEX-0002-02) for the support to the magnetometry platform. We acknowledge Dr Eric Riviere (Orsay, France) for helping us during magnetic measurements. S. M. is thankful for the Prime Minister Research Fellowship. S. K. S. acknowledges a generous seed grant from IIT Hyderabad and the Department of Science and Technology for the Startup-Research Grant (SRG/2020/001323).

Uncontrolled Keywords:

LN,ATOMS,FAMILY

Subjects:

Chemistry

Divisions:

Department of Chemistry

Depositing User:

. LibTrainee 2021

Date Deposited:

26 Sep 2022 07:28

Last Modified:

26 Sep 2022 07:28