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Magnetocaloric Properties of Heterometallic 3d-Gd Complexes Based on the [Gd(oda)3]3− Metalloligand.
- Source :
- Chemistry - A European Journal; Jan2016, Vol. 22 Issue 2, p802-808, 7p
- Publication Year :
- 2016
-
Abstract
- A series of heterometallic 3d-Gd<superscript>3+</superscript> complexes based on a lanthanide metalloligand, [M(H<subscript>2</subscript>O)<subscript>6</subscript>][Gd(oda)<subscript>3</subscript>] ⋅3 H<subscript>2</subscript>O [M=Cr<superscript>3+</superscript> ( 1-Cr)] (H<subscript>2</subscript>oda=2,2′-oxydiacetic acid), [M(H<subscript>2</subscript>O)<subscript>6</subscript>][MGd(oda)<subscript>3</subscript>]<subscript>2</subscript> ⋅3 H<subscript>2</subscript>O [M=Mn<superscript>2+</superscript> ( 2-Mn), Fe<superscript>2+</superscript> ( 2-Fe) and Co<superscript>2+</superscript> ( 2-Co)], and [M<subscript>3</subscript>Gd<subscript>2</subscript>(oda)<subscript>6</subscript>(H<subscript>2</subscript>O)<subscript>6</subscript>] ⋅12 H<subscript>2</subscript>O [M=Ni<superscript>2+</superscript> ( 3-Ni), Cu<superscript>2+</superscript> ( 3-Cu), and Zn<superscript>2+</superscript> ( 3-Zn)], are reported. Magnetic and heat-capacity studies revealed a significant impact on the magnetocaloric effect depending on the anisotropy of the 3d transition metal ions, as confirmed by comparison of the observed maximum values of −Δ S<subscript>m</subscript> between complexes 2-Co and 1-Cr. In these two complexes, the 3d metal ions have the same spin ( S=3/2 for Co<superscript>2+</superscript> and Cr<superscript>3+</superscript> ions), and the theoretical calculation suggested a larger −Δ S<subscript>m</subscript> value for 2-Co (47.8 J K<superscript>−1</superscript> kg<superscript>−1</superscript>) than 1-Cr (37.5 J K<superscript>−1</superscript> kg<superscript>−1</superscript>); however, the significant anisotropy of Co<superscript>2+</superscript> ions in 2-Co, which can result in smaller effective spins, gives a smaller value of −Δ S<subscript>m</subscript> for 2-Co (32.2 J K<superscript>−1</superscript> kg<superscript>−1</superscript>) than for 1-Cr (35.4 J K<superscript>−1</superscript> kg<superscript>−1</superscript>) at Δ H=9 T. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 09476539
- Volume :
- 22
- Issue :
- 2
- Database :
- Complementary Index
- Journal :
- Chemistry - A European Journal
- Publication Type :
- Academic Journal
- Accession number :
- 112066252
- Full Text :
- https://doi.org/10.1002/chem.201503796