Work

Mixed-Valent Mn Supertetrahedra and Planar Discs as Enhanced Magnetic Coolers

Year: 2008

Type: article

Abstract: The syntheses and structures of two decametallic mixed-valent Mn supertetrahedra using 2-amino-2-methyl-1,3-propanediol (ampH2), two decametallic mixed-valent Mn planar discs using 2-amino-2-methyl-1,3-propanediol (ampH2) and 2-amino-2-ethyl-1,3-propanediol (aepH2), and a tetradecametallic mixed-valent Mn planar disc using pentaerythritol (H4peol) are reported. The decametallic complexes display dominant ferromagnetic exchange and spin ground states of S = 22, and the tetradecametallic complex displays dominant antiferromagnetic exchange and a spin ground state of S = 7 +/- 1. All display large (the former) and enormous (the latter) magnetocaloric effect--the former as a result of negligible zero-field splitting of the ground state, and the latter as a result of possessing a high spin-degeneracy at finite low temperatures--making them the very best cooling refrigerants for low-temperature applications.

Source: Journal of the American Chemical Society

DOI: 10.1021/ja802829d

Authors: Maria Manoli, Anna Collins, Simon Parsons, Andrea Candini, Marco Evangelisti, Euan K. Brechin

Institution: University of Edinburgh

Language: English

Topic: Magnetism in coordination complexes

Subfield: Electronic, Optical and Magnetic Materials

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funders: Leverhulme Trust, Engineering and Physical Sciences Research Council

Awards: G2303360401, G6587963670