Synthesis, Structure, and Magnetic Properties of a Family of Complexes Containing a {Co^II₂Dy^III} Pivalate Core and a Pentanuclear Co^II₄Dy^III Derivative

Abstract

A series of new Co II -Ln III complexes with polynuclear {Co 2 Ln(NO 3 )(Piv) 6 } (Ln = La, Gd, Dy; Piv = pivalate) cores were prepared by self-assembly reactions or step-by-step assembly.[Co 2 Dy(NO 3 )(Piv) 6 (MeCN) 2 ] was used as the starting compound for the synthesis of the trinuclear analogue [Co 2 Dy(NO 3 )(Piv) 6 -(py) 2 ] (py = pyridine) and the pentanuclear complex [{Co 2 Dy-(NO 3 )(Piv) 6 }{CoL(Piv)(H 2 O)} 2 ][NO 3 ] 2 [L = 2,6-bis(2-pyridyl)-4-(4pyridyl)pyridine]. The effects of the coordination environment and temperature on the distortion of the Ln III coordination polyhedra were analyzed for a series of coordination compounds with M II 2 Ln III cores and close analogues. The distortion of the Ln III polyhedron depends on both the composition of [a] N.

The First Series of Heterometallic LnIII‐VIV Complexes Based on Substituted Malonic Acid Anions: Synthesis, Structure and Magnetic Properties

“…Complexes of 3d‐4f metals are considered as good candidates for SMMs due to high anisotropy of some lanthanide ions (Tb III , Dy III , Ho III , Er III , Tm III , Yb III ) and ferromagnetic coupling observed, for example, between Cu II ‐Ln III and Ni II ‐Ln III ions. [3a], [3b], [3g], The majority of known 3d‐4f complexes contain Cr III , Mn II , Fe III ,[3b], [3h], Co II ,[3l], Ni II ,[3b], [3d], [3k], [4d], [4c], or Cu II ions. [3a], [3e], [3g], [4a], [4b], [4c], Meanwhile 3d‐4f compounds containing a vanadyl ion V IV O 2+ as the 3d center with a single 3d electron ( S = 1 / 2 ) are quite rare, although they may provide insight into the mechanism of spin–spin exchange interactions.…”

The First Example of 3 d‐4 f‐Heterometallic Carboxylate Complex Containing Phosphine Ligand

“…These results confirm that both intra‐ (Co…Co 7.381 Å) and intermolecular (the shortest Co…Co distance is 9.813 Å) exchange interactions of Co(II) ions are absent or negligible small. In our previous study [12a] the magnetic measurements data simulation for compound [Co 2 La(Piv) 6 (NO 3 )(MeCN) 2 ] ( 1 ) revealed weak intermolecular exchange interactions (z J ′=−0.05 cm −1 ) which could be caused by relatively short intermolecular Co…Co contacts in the crystal lattice (equal to 6.006 Å). The g‐factor and D for 3 and 1 were comparable.…”

Versatile Reactivity of MnII Complexes in Reactions with N-Donor Heterocycles: Metamorphosis of Labile Homometallic Pivalates vs. Assembling of Endurable Heterometallic Acetates

“…Calculation of the exchange coupling parameters were performed by full-matrix diagonalization using the Mjöllnir software [16,83]. Uncertainty values of simulation parameters were estimated as described previously [33]. Briefly, digits in brackets indicated deviation of the value, which caused 10% increase of R 2 .…”

“…Such rearrangement reactions lead to the formation of certain polynuclear cores, which are most stable under the reaction conditions. For example, binuclear cores M2(O2CR)4 (M II = Cu, Zn, Co, Ni) [28], trinuclear cores Fe III 3 or Fe III 2M II (M = Ni, Co, Mn) [29][30][31][32], M II 2Ln III (M II = Zn, Co, Ni; Ln is lanthanide) [33][34][35] often form due to their exceptional stability in various media. However, the result of such rearrangements is not always predictable, since many factors may influence the reaction pathway.…”