Fluoride-Bridged {Gd-III M-3(III) (2)} ( M= Cr, Fe, Ga) Molecular Magnetic Refrigerants**
DSpace at IIT Bombay
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Title |
Fluoride-Bridged {Gd-III M-3(III) (2)} ( M= Cr, Fe, Ga) Molecular Magnetic Refrigerants**
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Creator |
PEDERSEN, KS
LORUSSO, G MORALES, JJ WEYHERMULLER, T PILIGKOS, S SINGH, SK LARSEN, D SCHAU-MAGNUSSEN, M RAJARAMAN, G EVANGELISTI, M BENDIX, J |
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Subject |
density functional calculations
fluoride ligands lanthanides magnetic properties magnetic refrigeration METAL-ORGANIC FRAMEWORK COMPLEXES CLUSTER CAGES |
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Description |
The reaction of fac-[(MF3)-F-III(Me(3)tacn)]xH(2)O with Gd(NO3)(3)5H(2)O affords a series of fluoride-bridged, trigonal bipyramidal {(Gd3M2III)-M-III} (M=Cr (1), Fe (2), Ga (3)) complexes without signs of concomitant GdF3 formation, thereby demonstrating the applicability even of labile fluoride-complexes as precursors for 3d-4f systems. Molecular geometry enforces weak exchange interactions, which is rationalized computationally. This, in conjunction with a lightweight ligand sphere, gives rise to large magnetic entropy changes of 38.3Jkg(-1)K(-1) (1) and 33.1Jkg(-1)K(-1) (2) for the field change 7T0T. Interestingly, the entropy change, and the magnetocaloric effect, are smaller in 2 than in 1 despite the larger spin ground state of the former secured by intramolecular Fe-Gd ferromagnetic interactions. This observation underlines the necessity of controlling not only the ground state but also close-lying excited states for successful design of molecular refrigerants.
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Publisher |
WILEY-V C H VERLAG GMBH
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Date |
2014-12-28T12:49:19Z
2014-12-28T12:49:19Z 2014 |
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Type |
Article
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Identifier |
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 53(9)2394-2397
1433-7851 1521-3773 http://dx.doi.org/10.1002/anie.201308240 http://dspace.library.iitb.ac.in/jspui/handle/100/16602 |
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Language |
English
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