Building of a novel Mn12 Single Molecule Magnet by assembly of anisotropic {Mn3(μ3-O)(salox)3}+ triangles

Abstract

Assembly of triangular {Mn(III)(3)(O)(salox)(3)}(+) fragments mediated by azido ligands, results in the dodecanuclear [Mn(12)O(4)(salox)(12)(N(3))(4)(MeOH)(4)(H(2)O)(2)] complex with S = 8 ground state and SMM response.

Manganese–Salicyloximate Clusters Starting from [MnII(hfacac)2]: From Mn4 to Mn12

“…In this work we report the clusters [Mn 6 (O) 2 (salox) 6 (CF 3 COO) 2 (EtOH) 4 ] · Et 2 O ( 1· Et 2 O), [Mn 4 (Mesalox) 4 (MesaloxH) 4 ] ( 2 ), [Mn 6 (Etsalox) 6 (O) 2 (MeO) 4 (MeOH) 2 ] · MeOH ( 3· MeOH), [Mn 12 (salox) 12 (O) 4 (N 3 ) 4 (H 2 O) 2 (MeOH) 6 ] · 4MeOH · 2H 2 O ( 4· 4MeOH · 2H 2 O) and [Mn 8 (Mesalox) 6 (O) 2 (N 3 ) 6 (MeOH) 8 ] · 4MeOH ( 5· 4MeOH). Complex 1 is a new member of the [Mn 6 ] family of clusters and 4 provides a unique Mn 12 topology with SMM response (previously reported in a communication) 16b. Noteworthy, compounds 2 , 3 and 5 are polymorphs of the previously reported complexes 2a· 3.5MeCN, 3a· MeOH and 5a· 10MeOH with different hydrogen‐bonding patterns or solvent content, resulting in some cases in drastic differences in their magnetic response.…”

“…The magnetic response of compound 4 was discussed in depth in the previous communication16b and thus only a brief description will be given here. The room‐temperature χ M T value for compound 4 is 31.8 cm 3 K mol –1 , slightly lower than the expected value for 12 non‐interacting S = 2 spins (36.0 cm 3 K mol –1 ; Figure 10).…”

A Salicylaldoxime [Mn12] Complex with an Unprecedented [MnIII4MnII8(μ‐OCH3)4] Core

“…Examples are [Mn III 4 Mn II 8 (μ 5 ‐O) 2 (μ 3 ‐OMe) 2 (Hpeol) 4 (O 2 CPh 2 ) 10 (H 2 O) 2 ] · 6MeCN (H 4 peol = pentaerythritol),8 the valence‐sandwich [Mn 12 O 2 (OMe) 2 (thme) 4 (OAc) 10 (H 2 O) 4 ] · 2MeOH {H 3 thme = 1,1,1‐tris(hydroxymethyl)methane}9 and finally [Mn III 4 Mn II 8 (CH 3 O) 2 (C 2 H 3 O 2 ) 4 (C 5 H 9 O 4 ) 4 Cl 6 O 2 (CH 4 O) 4 (H 2 O) 2 ] (with propanolate and pentaerythritol ligands) 10. It is worth further emphasizing that 1 displays a rare topology with [Mn 4 ] cages as building blocks rather than the well‐known [Mn 3 O] triangular unit usually observed in the chemistry of Mn oxime complexes as exemplified by the oxime‐bridged [Mn 12 ] complex reported by Cordero et al3…”

“…For instance, Milios et al2a used [Mn 3 ] building blocks to construct [Mn 8 ] aggregates with enhanced magnetic properties, and Jones et al1a reported on 1D coordination networks of [Mn 6 ] SMMs bridged by isophthalate/succinate ligands. Another interesting example was reported by Cordero et al,3 who obtained a new [Mn 12 ] complex by assembly of triangular {Mn III 3 (O)(sao) 3 } + units with Mn(hfacac) 2 as precursor in the presence of azide ligands (hfacac = hexafluoroacetylacetonate; saoH 2 = salicylaldoxime). This was part of a strategy based on assembling anisotropic building blocks to afford large ground spin states.…”

Coordination Clusters of 3d-Metals That Behave as Single-Molecule Magnets (SMMs): Synthetic Routes and Strategies

“…A good strategy is the use of building-block approaches to link SMMs together employing carefully chosen linker groups that will provide weak inter-SMM interactions and ensure that discrete oligomeric species (and not polymers) are obtained. The groups of Papaefstathiou, Brechin, Christou, and Escuer, among others, have successfully contributed into this general synthetic goal (Stoumpos et al, 2009 ; Inglis et al, 2010 ; Cordero et al, 2011 ; Nguyen et al, 2011 , 2015 , 2016 ; Mowson et al, 2013 ). We herein present examples of the supramolecular approaches which have been almost exclusively developed in Mn SMM chemistry.…”