Wells-Dawson cages as molecular refrigerants.
Five clusters with the general formula [Ni6Gd6(μ3-OH)2(μ2-OAc)2(O3PR)6(O2C(t)Bu)16], where R = methyl (1), phenyl (2), n-hexyl (3), benzyl (4), n-octyl (5), have been prepared. All of the clusters have a {Ni6Gd6P6} core that can be related to the Wells-Dawson ion. We have also prepared analogues where the gadolinium is replaced with diamagnetic yttrium: [Ni6Y6(μ3-OH)2(μ2-OAc)2(O3PR)6(O2C(t)Bu)16] (R = methyl (6), n-hexyl (7), benzyl (8), n-octyl (9)), allowing the magnetic exchange within the {Ni3} units to be analyzed by modeling as the sum of two noninteracting isosceles triangles. The variation in the magnetic entropy changes for magnetization (-ΔSM) among compounds 1-5 could be attributed not only to the molecular weight of the compounds but also to intramolecular magnetic interactions.
School of Chemistry and Photon Science Institute, The University of Manchester , Oxford Road, Manchester M13 9PL, U.K.
Eufemio Moreno
EM
Pineda
Floriana
F
Tuna
Yan-Zhen
YZ
Zheng
Richard E P
RE
Winpenny
Eric J L
EJ
McInnes
D005682:Gadolinium / Q000737:chemistry*; D059346:Magnets / Q000737:chemistry*; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry*; D015019:Yttrium / Q000737:chemistry*
D009942:Organometallic Compounds; D015019:Yttrium; D005682:Gadolinium