Theoretical Studies on Polynuclear {CuII5GdIIIn} Clusters (n = 4, 2): Towards Understanding Their Large Magnetocaloric Effect

Thayalan Rajeshkumar; Harshini V. Annadata; Marco Evangelisti; Stuart K. Langley; Nicholas F. Chilton; Keith S. Murray; Gopalan Rajaraman

doi:10.1021/ic502651w

Theoretical Studies on Polynuclear {Cu^II₅Gd^III_n} Clusters (n = 4, 2): Towards Understanding Their Large Magnetocaloric Effect

Thayalan Rajeshkumar, Harshini V. Annadata, Marco Evangelisti, Stuart K. Langley, Nicholas F. Chilton, Keith S. Murray, Gopalan Rajaraman

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

59 Citations (Scopus)

Abstract

Density functional theory (DFT) studies on two polynuclear clusters, [Cu^II₅Gd^III₄O₂(OMe)₄(teaH)₄(O₂CC(CH₃)₃)₂(NO₃)₄] (1) and [Cu₅Gd₂(OH)₄(Br)₂-(H₂L)₂(H₃L)₂(NO₃)₂(OH₂)₄] (2), have been carried out to probe the origin of the large magnetocaloric effect (MCE). The magnetic exchange interactions for 1 and 2 via multiple pathways are estimated using DFT calculations. While the calculated exchange parameters deviate from previous experimental estimates obtained by fitting the magnetic data, the DFT parameter set is found to offer a striking match to the magnetic data for both complexes, highlighting the problem of overparameterization. Magnetostructural correlations for {Cu–Gd} pairs have been developed where both the Cu–O–Gd angles and Cu–O–Gd–O dihedral angles are found to significantly influence the magnitude and sign of the exchange constants. The magnitude of the MCE has been examined as a function of the exchange interactions, and clues on how the effect can be enhanced are discussed.

Original language	English
Pages (from-to)	1661-1670
Number of pages	10
Journal	Inorganic Chemistry
Volume	54
Issue number	4
DOIs	https://doi.org/10.1021/ic502651w
Publication status	Published - 1 Feb 2015
Externally published	Yes

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https://pubs.acs.org/doi/10.1021/ic502651w

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@article{79797cad6b0a49709c65d7016f478052,

title = "Theoretical Studies on Polynuclear {CuII5GdIIIn} Clusters (n = 4, 2): Towards Understanding Their Large Magnetocaloric Effect",

abstract = "Density functional theory (DFT) studies on two polynuclear clusters, [CuII5GdIII4O2(OMe)4(teaH)4(O2CC(CH3)3)2(NO3)4] (1) and [Cu5Gd2(OH)4(Br)2-(H2L)2(H3L)2(NO3)2(OH2)4] (2), have been carried out to probe the origin of the large magnetocaloric effect (MCE). The magnetic exchange interactions for 1 and 2 via multiple pathways are estimated using DFT calculations. While the calculated exchange parameters deviate from previous experimental estimates obtained by fitting the magnetic data, the DFT parameter set is found to offer a striking match to the magnetic data for both complexes, highlighting the problem of overparameterization. Magnetostructural correlations for {Cu–Gd} pairs have been developed where both the Cu–O–Gd angles and Cu–O–Gd–O dihedral angles are found to significantly influence the magnitude and sign of the exchange constants. The magnitude of the MCE has been examined as a function of the exchange interactions, and clues on how the effect can be enhanced are discussed.",

author = "Thayalan Rajeshkumar and Annadata, {Harshini V.} and Marco Evangelisti and Langley, {Stuart K.} and Chilton, {Nicholas F.} and Murray, {Keith S.} and Gopalan Rajaraman",

year = "2015",

month = feb,

day = "1",

doi = "10.1021/ic502651w",

language = "English",

volume = "54",

pages = "1661--1670",

journal = "Inorganic Chemistry",

issn = "0020-1669",

publisher = "American Chemical Society",

number = "4",

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TY - JOUR

T1 - Theoretical Studies on Polynuclear {CuII5GdIIIn} Clusters (n = 4, 2)

T2 - Towards Understanding Their Large Magnetocaloric Effect

AU - Rajeshkumar, Thayalan

AU - Annadata, Harshini V.

AU - Evangelisti, Marco

AU - Langley, Stuart K.

AU - Chilton, Nicholas F.

AU - Murray, Keith S.

AU - Rajaraman, Gopalan

PY - 2015/2/1

Y1 - 2015/2/1

N2 - Density functional theory (DFT) studies on two polynuclear clusters, [CuII5GdIII4O2(OMe)4(teaH)4(O2CC(CH3)3)2(NO3)4] (1) and [Cu5Gd2(OH)4(Br)2-(H2L)2(H3L)2(NO3)2(OH2)4] (2), have been carried out to probe the origin of the large magnetocaloric effect (MCE). The magnetic exchange interactions for 1 and 2 via multiple pathways are estimated using DFT calculations. While the calculated exchange parameters deviate from previous experimental estimates obtained by fitting the magnetic data, the DFT parameter set is found to offer a striking match to the magnetic data for both complexes, highlighting the problem of overparameterization. Magnetostructural correlations for {Cu–Gd} pairs have been developed where both the Cu–O–Gd angles and Cu–O–Gd–O dihedral angles are found to significantly influence the magnitude and sign of the exchange constants. The magnitude of the MCE has been examined as a function of the exchange interactions, and clues on how the effect can be enhanced are discussed.

AB - Density functional theory (DFT) studies on two polynuclear clusters, [CuII5GdIII4O2(OMe)4(teaH)4(O2CC(CH3)3)2(NO3)4] (1) and [Cu5Gd2(OH)4(Br)2-(H2L)2(H3L)2(NO3)2(OH2)4] (2), have been carried out to probe the origin of the large magnetocaloric effect (MCE). The magnetic exchange interactions for 1 and 2 via multiple pathways are estimated using DFT calculations. While the calculated exchange parameters deviate from previous experimental estimates obtained by fitting the magnetic data, the DFT parameter set is found to offer a striking match to the magnetic data for both complexes, highlighting the problem of overparameterization. Magnetostructural correlations for {Cu–Gd} pairs have been developed where both the Cu–O–Gd angles and Cu–O–Gd–O dihedral angles are found to significantly influence the magnitude and sign of the exchange constants. The magnitude of the MCE has been examined as a function of the exchange interactions, and clues on how the effect can be enhanced are discussed.

U2 - 10.1021/ic502651w

DO - 10.1021/ic502651w

M3 - Article

SN - 0020-1669

VL - 54

SP - 1661

EP - 1670

JO - Inorganic Chemistry

JF - Inorganic Chemistry

IS - 4

ER -

Theoretical Studies on Polynuclear {CuII5GdIIIn} Clusters (n = 4, 2): Towards Understanding Their Large Magnetocaloric Effect

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Theoretical Studies on Polynuclear {Cu^II₅Gd^III_n} Clusters (n = 4, 2): Towards Understanding Their Large Magnetocaloric Effect