Slow magnetic relaxation in a {EuCu5} metallacrown. Issue 5 (8th January 2019) - Wang, Jin
Abstract : A {Eu III Cu5 } metallacrown displays field-induced slow magnetic relaxation, in which the Eu III with diamagnetic ground state enhances the relaxation rates. Abstract : A 3d–4f heterometallic metallacrown with formula of [EuCu5 (quinha)5 (sal)2 (py)5 ]CF3 SO3 ·py·3H2 O (1 ) (H2 quinha = quinaldichydroxamic acid; Hsal = salicylaldehyde) has been synthesized. This complex shows field-induced slow magnetic relaxation via a Raman-like process, where studies of the isostructural {LuCu5 } (2 ) and {YCu5 } (3 ) complexes show that the slow dynamics mainly arise from the {Cu5 } S = 1/2 ground state rather than the Eu III ion. However, the Eu III ion enhances the relaxation rates of the {Cu5 } unit which likely arises from second-order effects in the formally diamagnetic 7 F0 ground state of Eu III .