Synthesis, Structure, and Magnetic Properties of a Large Lanthanide–Transition‐Metal Single‐Molecule Magnet

Abstract

CommunicationsThe Dy-Mn cluster depicted is the first to behave as a single-molecule magnet. The trimeric Mn III 2 Mn IV "wings" combine with the hexagonal dysprosium ring to from the cluster, which displays an out of phase magnetic susceptibility signal in ac SQUID experiments. For more information, see the Communication by M. L. Kirk, V. L. Pecoraro, and co-workers on the following pages.

Nickel(II) Thiolate Complexes with a Flexible cyclo‐{Ni10S20} Framework

“…[1,2] In contrast to the ubiquitous O-or N-bridged metal rings, which exhibit fascinating cluster configurations, [3][4][5][6][7][8][9] the study of the S-bridged variants remains limited. Homoleptic nickel(ii) thiolates [{Ni(m-SR) 2 } n ] occasionally generate cyclic structures by forming shared edges of the square NiS 4 coordination planes, and several hexanuclear ring clusters [{Ni(m-SR) 2 } 6 ] have been reported.…”

“…[20] Dance et al [13] pointed out that the Ni-S(R)-Ni bond angles of doubly bridged {Ni(m-SR) 2 Ni} units tend to increase as the pyramidality of the m-S atoms decreases. [10][11][12][13]21] The averaged Ni-S(tBu)-Ni bond angle of 928 for 3 a (and for 3 b) is evidently larger than that of 2 (838) and those of the related complexes [{Ni(m-SR) 2 } n ] (n = 4,5,6,8). [10][11][12][13] The larger Ni-S(tBu)-Ni bond angles, in turn, bring about the larger dihedral angles between the adjacent NiS 2 planes of 3 a and 3 b, and the larger decanuclear ring is the consequence.…”

[GdNi6] and [LaNi6]: High‐Field EPR Spectroscopy and Magnetic Studies of Exchange‐Coupled Octahedral Clusters

“…[13] In contrast, the magnetic coupling between 3d and 4f metals is still not understood very well and has therefore not been exploited as a potential entry to a new category of SMMs. [14,15] Of all open-shell 4f ions, Gd III has been studied the most since it does not show the complicating effect of spin-orbit coupling. The quasi-systematic ferromagnetic nature of the coupling between Cu II and Gd III has been corroborated by a considerable amount of experimental data, [16] and a recent report has established the theoretical grounds of this observation.…”

Recent Progress in the Realm of Homonuclear Ln6 Single molecule magnets: Structural Overview and Synthetic Approaches

“…Huge enthusiasm followed the stupendous discovery of this dodecametallic manganese-acetate cage [Mn 12 O 12 (OAc) 16 (H 2 O) 4 ], which for the first time showed the unique property of retaining the magnetization for long time periods in the absence of any external magnetic field. This famous transition metal coordination compound established itself as the progenitor of an enormous family of magnetic materials, known as single molecule magnets (SMMs) (Zaleski et al, 2004;Gatteschi et al, 2006;Lin et al, 2008;Costes et al, 2008;Chibotaru et al, 2008;Gamer et al, 2008;Zheng et al, 2009;Burrow et al, 2009;Xu et al, 2010;Ishikawa et al, 2003;Luzon et al, 2008;Lin et al, 2009;AlDamen et al, 2008;Cardona-Serra et al, 2012;Joarder et al, 2012), which could be precisely defined as such molecular species, essentially aggregates possessing both non-negligible high-spin ground state (S) and uniaxial (negative) Ising-like magnetic anisotropy |D| (taking into account the Hamiltonian: H = DS z 2 ), leading to an anisotropy energy barrier (U) (S 2 |D| or (S 2 -1/4)|D| for integer or half integer spins respectively, for the reversal of magnetization (Habib et al, 2013;Chakov et al, 2006). One remarkable aspect is that, this relationship applies satisfactory to 3d and 4d-transition metal systems but is unable to represent correctly the experimental barriers in lanthanide complexes.…”