A {Gd 12 Na 6 } Molecular Quadruple-Wheel with a Record Magnetocaloric Effect at Low Magnetic Fields and Temperatures.
Thomais G TziotziDavid GraciaScott J DalgarnoJürgen SchnackMarco EvangelistiEuan K BrechinConstantinos J MiliosPublished in: Journal of the American Chemical Society (2023)
Reaction of Gd(OAc) 3 ·4H 2 O, salicylaldehyde and CH 3 ONa in MeCN/MeOH affords [Gd 12 Na 6 (OAc) 25 (HCO 2 ) 5 (CO 3 ) 6 (H 2 O) 12 ]·9H 2 O.0.5MeCN ( 1 ·9H 2 O.0.5MeCN), whose structure describes a quadruple-wheel consisting of two {Na 3 } and two {Gd 6 } rings. The magnetic properties of 1 reveal very weak antiferromagnetic interactions between the Gd III ions, which give rise to a record magnetocaloric effect at low applied magnetic fields and low temperatures. The magnetic entropy change reaches -Δ S m = 29.3 J kg -1 K -1 for full demagnetization from B = 1 T at T = 0.5 K.