Slow Magnetic Relaxation in an Octanuclear Manganese Chain

Abstract

A one-dimensional chain containing a mixed-valence octanuclear manganese(II,III) building unit, (NEt(4))(2n)[Mn(8)O(2)(salox)(6)(N(3))(8)(MeOH)(3)](n) (H(2)salox = salicylaldoxime), was synthesized and characterized structurally and magnetically. Each building unit contains a [Mn(II)(2)Mn(III)(6)O(2)](18+) structural topology. The frequency dependence of the out-of-phase component in alternating current magnetic susceptibilities and hysteresis loops for the complex indicates single-chain-magnet-like behavior.

A toolbox of building blocks, linkers and crystallisation methods used to generate single-chain magnets

“…16, left), i.e. most of the SCMs falling in this category are based on [Mn III 3 O] 7+ units [92][93][94][95][96][97][98][99], generally using salicylaldoximate-type capping ligands (Fig. 16, right).…”

“…24). Several SCMs have been reported using end-on azides [39,41,42,[44][45][46]49,52,74,89,94,96,127], and a handful have been reported using end-to-end azides [76,88,97,98]. Hendrickson and co-workers reported a mixed end-on end-to-end azide SCM (Fig.…”

A family of hexanuclear Mn(III) single-molecule magnets

“…The ease of synthesis of [Mn 3 ] and [Mn 6 ] and their relative solution stability have enabled them to be utilized as starting materials -building blocks for construction of a host of discrete and infinite supramolecular architectures [14,21,31,37,41,[44][45][46][47][48][49][50][51][52][53][54][55][56][57]. The employment of auxiliary pyridyl-type ligands into the reaction mixtures of [Mn 3/6 ] or in solutions of preformed [Mn 3/6 ] has yielded several discrete (i.e.…”

“…1D and 2D coordination polymers) species featuring unique types of entanglement [37,48], while the use of poly-carboxylate ligands has driven the formation of 1D and 2D coordination polymers (or Metal-Organic Frameworks, MOFs) based on [Mn 6 ] SMMs [21,45,46,52,55,58]. Several Single-Chain Magnets (SCMs; or in some cases chains of non-interacting SMMs) consisting of [Mn 3/6 ] clusters have also been reported [47,50,51,54,57].…”

A new dodecanuclear manganese single-molecule magnet from the arrangement of manganese triangles

“…The use of salicylaldoxime ligands in manganese chemistry has proven to be extremely successful in the synthesis of new polynuclear complexes [8][9][10][11][12]. Some SMMs and single-chain-magnets (SCMs), using salicylaldoxime (H 2 salox) and its derivatives, were reported [13][14][15][16][17]. Moreover, the azide bridging ligand often mediates ferromagnetic exchange between paramagnetic centers, and this property has been recently exploited in the preparation of some SMMs [18][19][20] and SCMs [21][22][23][24].…”