Heterometallic Mn^III₄Ln₂ (Ln = Dy, Gd, Tb) Cross-Shaped Clusters and Their Homometallic Mn^III₄Mn^II₂ Analogues

Abstract

The employment of di-2-pyridyl ketone, (py)CO, in heterometallic Mn/4f and homometallic Mn cluster chemistry has yielded six MnLn and two MnMn structurally related clusters, namely, [MnLnO{(py)CO}(NO)(RCO)(HO)](NO) (Ln = Gd, 1, 5; Dy, 2; Tb, 3; R = Et, 1-3; Me, 5), [MnDyO{(py)CO}(NO)(EtCO)(HO)(MeOH)]·0.7MeOH·0.8HO (4·0.7MeOH·0.8HO), [MnGdO{(py)CO}(NO)(CHClCO)(MeOH)(py)]·2MeOH (6·2MeOH), [MnO{(py)CO}(py)(HO)](ClO)·4HO (7·4HO), and [MnO{(py)CO}(NO)(py)] (8), where (py)CO is the dianion of the gem-diol derivative of (py)CO. The compounds possess a new type of cross-shaped structural core, which in the case of 1-6 is essentially planar, whereas in 7 and 8 it deviates from planarity. Clusters 1-6 are rare examples of Mn/4f species bearing (py)CO or its derivatives, despite the fact that this ligand has been well-studied and proven a rich source of more than 200 metal compounds so far. Variable-temperature, solid-state direct-current and alternating-current magnetization studies were performed on complexes 1-5, 7, and 8 revealing that the dominant exchange interactions between the metal ions are antiferromagnetic and indicating ground-state spin values of S = 5 (for 1), 6 (for 5), and 2 (for 7 and 8).

Synthesis, Structural, and Magnetic Characterization of a Mixed 3d/4f 12-Metallacrown-4 Family of Complexes

“…The values of both models are in an excellent agreement. Note that antiferromagnetic exchange interactions, in Mn III -Gd III and other 3d-Gd III species, possessing the 3dx2−y2 orbital unoccupied, are quite often observed [44][45][46][47]. Here is the first time that fitting of the magnetic susceptibility data for 3d/Gd III interactions has been reported, within the MC family of complexes.…”

Paramagnetic solid-state NMR assignment and novel chemical conversion of the aldehyde group to dihydrogen ortho ester and hemiacetal moieties in copper(ii)- and cobalt(ii)-pyridinecarboxaldehyde complexes

“…The study of systems containing paramagnetic centers has proved useful in a variety of elds ranging from the structure elucidation of metalloproteins [15][16][17][18] to the characterization of catalytic organometallic complexes 9,[19][20][21] and Metal Organic Frameworks (MOFs). 22 In this context, solid-state Nuclear Magnetic Resonance (ss-NMR) is a powerful tool for structural characterization of organic/inorganic compounds, providing information about connectivity and interaction between atoms in both crystalline and non-crystalline samples.…”

Structural and Magnetic Variations in a Family of Isoskeletal, Oximate‐Bridged {MnIV2MIII} Complexes (MIII=Mn, Gd, Dy)

“…To this end, the aforementioned {Mn 19 } cluster has been successfully transformed to a {DyMn 18 } SMM via the deliberate replacement of an 8‐coordinate Mn II ion with Dy III . The only other example ‐to our knowledge‐ where a homometallic Mn‐containing non‐SMM was converted to a Mn/Ln SMM is that of the antiferromagnetic {Mn II 2 Mn III 4 } to {Dy 2 Mn III 4 } …”

“…[13] The only other example -to our knowledge-w here ah omometallic Mn-containingn on-SMM was converted to aM n/Ln SMM is that of the antiferromagnetic {Mn II 2 Mn III 4 }t o{ Dy 2 Mn III 4 }. [14] We herein report (i)the self-assembly synthesis of ar are, ferromagnetically coupledb ut non-SMM{ Mn III Mn IV 2 }( 1)c omplex, bearing exclusively the dianion of the acenaphthenequinone dioxime( acndH 2 ,F igure 1, bottom)b ridging/chelating ligand [IUPAC name: N,N'-dihydroxy-1,2-acenaphthylenediimine],a nd (ii)its deliberate conversion to both al arger-spin {GdMn IV 2 }( 2) compound and a{ DyMn IV 2 }( 3)S MM, withouta ffecting the nuclearity,t opology,m etal oxidation state descriptions, and the nature of predominant magnetic exchange interactions. The oximate-bridged complexes 1-3 manifest themselvesa sarare opportunity for ac omprehensive magneto-structural correlation investigating in depth the Mn···Mna nd Mn···Ln magnetic coupling, sincet hey are nearly isoskeletal and perhaps most importantly,they are oxido-free bridged.…”