The first amino acid manganese cluster: a [MnIV2MnIII3] dl-valine cage

Kozoni, Chrysa; Siczek, Miłosz; Lis, Tadeusz; Brechin, Euan K.; Milios, Constantinos J.

doi:10.1039/b916258p

Cited by 13 publications

(5 citation statements)

References 33 publications

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“…ligands and a source of M II (M = Mn, Zn) ions to afford either [M II 2 Mn 3 III O(X)(R-sao) 3 (N 3 ) 6 ] 3cationic species, 32 where the excess of base causes the partial oxidative dissociation and rearrangement of the building block of the cluster, so that the linkage between the two [Mn III 2 Mn IV O(R-sao) 3 (MeOH)] 2+ triangles is accomplished through MeObridges. The same is true for the complex [Mn III 3 Mn IV 2 O 2 (CH 3 O)(Et-sao) 6 (val)], 33 which comprises of two vertex-sharing triangles, sharing a Mn IV apex (val = valine). The effect of a strongly basic environment is also evident through the isolation of [Mn III 9 O 4 (OMe…”

Section: Synthesesmentioning

confidence: 72%

Ferromagnetic manganese “cubes”: from PSII to single-molecule magnets

et al. 2010

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The reaction of Mn(O₂CMe)₂·2H₂O with Me-saoH₂ (Me-saoH₂ = 2-hydroxyphenylethanone oxime) in MeCN forms the complex [Mn(III)₄(Me-sao)₄(Me-saoH)₄] (1) in good yields. Replacing Me-saoH₂ with Naphth-saoH₂ (Naphth-saoH₂ = 2-hydroxy-1-napthaldoxime) in the presence of CH₃ONa forms the complex [Mn(III)₄(Naphth-sao)₄(Naphth-saoH)₄] (2) in low yields, while the reaction between Mn(ClO₄)₂·6H₂O, Et-saoH₂ (Et-saoH₂= 2-hydroxypropiophenone oxime) and NBu₄OH in MeCN gives the complex [Mn(III)₄(Et-sao)₄(Et-saoH)₄] (3) in moderate yields. All three tetrametallic cages exclusively contain Mn(III) centres arranged in a "cube"-like topology, in which the metal centres are connected by -N-O(oximate) groups. The magnetic properties of 1-3 are near identical, revealing the presence of only ferromagnetic interactions between the metal ions leading to high-spin ground states of S = 8. The complexes display frequency dependent out-of-phase signals in ac susceptibility studies and, in the case of 1 single-molecule magnetism has been observed by means of single-crystal hysteresis loop measurements.

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Section: Synthesesmentioning

confidence: 72%

Ferromagnetic manganese “cubes”: from PSII to single-molecule magnets

et al. 2010

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“…This compound was obtained as given in ref. 14 C,50.33;H,5.13;N,7.22. Found: C,50.42;H,4.98;N,7.13 (1 mmol, 137 mg) were stirred in MeOH (20 ml) for a period of 10 min to form a colourless solution.…”

Section: Synthesesmentioning

confidence: 99%

“…5 K. This behaviour is consistent with dominant antiferromagnetic interactions within the metallic cluster with the low temperature c M T value suggesting a S ª 2 ground-state. As previously reported, 14 despite the fact that inspection of the molecular structure reveals the presence of six operating exchange pathways, we successfully simulated the data by employing the 2J-model of Fig. 7 and the Hamiltonian of eqn ( 1), based on our previous experience modelling manganese-oximate systems.…”

Section: Magnetochemistrymentioning

confidence: 99%

Polynuclear manganese amino acid complexes

et al. 2010

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The reaction of MnCl(2).4H(2)O with DL-valine (Val) in MeOH in the presence of Et-saoH(2) (2-hydroxypropiophenone oxime) and NEt(4)OH forms the complex [Mn(III)(3)Mn(IV)(2)O(2)(CH(3)O)(Et-sao)(6)(Val)].Val.1.5H(2)O (1.Val.1.5H(2)O) in very good yields. A similar reaction of MnCl(2).4H(2)O with Glycine (Gly) in MeOH in the presence of saoH(2) (salicylaldoxime) and Ca(OH)(2) yields the complex [Mn(III)(3)O(sao)(3)(Gly)Cl(MeOH)(3)].1.87 MeOH.0.13H(2)O (2.1.87 MeOH.0.13H(2)O). Replacing saoH(2) with Me-saoH(2) (2-hydroxyethanone oxime) and Gly with HPABA (para-aminobenzoic acid) in the presence of CH(3)ONa in MeOH forms the complex [Mn(6)O(2)(PABA)(2)(Me-sao)(6)(MeOH)(4)(H(2)O)(2)].2[Mn(6)O(2)(PABA)(2)(Me-sao)(6)(MeOH)(2)].11 MeOH (3.11 MeOH) in moderate yields. Magnetic studies for 1 and 2 reveal the presence of both ferromagnetic and antiferromagnetic interactions, leading to S = 2 ground states for both complexes. Complexes 1 and 2 represent the first examples of polynuclear manganese complexes with any naturally occurring alpha-amino acid, while 3 is the first structurally characterised example of a manganese para-aminobenzoate complex.

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“…The topological analysis of compound 8 gives an NDk-m symbol 2,3,4M5-1 and this is the first example ever seen in Ni chemistry. Interestingly, the latter topology can be found in compounds containing solely Mn, 72,73 Fe, 74 Co [75][76][77][78] and Zn. 79…”

Section: Solution Studiesmentioning

confidence: 98%