Synthesis, structural characterization and magnetic behaviour of a family of [CoIII2LnIII2] butterfly compounds

Abstract

We have successfully prepared and structurally characterized a family of butterfly-like [CoLn] complexes where all magnetic properties are due to the Ln(iii) ions. The complexes with Ln = Tb(1), Dy(2), Ho(3), Er(4) and Yb(5) are iso-structural. An exception is the complex with Ln = Gd(6) which strings in a one dimensional chain. The structural similarity together with the high tendency of the crystallites to align under an applied magnetic field allowed an overall DC magnetic data treatment to extract phenomenological crystal field parameters and hence to determine the ground state multiplet energy level splitting. The Dy(iii) member is the only one showing slow relaxation of magnetization under zero DC applied field, while all the others need a small DC applied field.

Two Series of Substituent‐Group‐Directed Adipate‐Based Lanthanide Coordination Polymers: Syntheses, Structures, Photoluminescence, and Magnetism

“…CPs 6 and 12 exhibit the frequency‐dependent out‐of‐phase (χ'') signals from 100 to 1000 Hz (Figure and Figure ), indicating a weak slow magnetic relaxation behavior. However, no obvious peaks were observed, which is possibly attributed to the quantum tunneling of the magnetization . In order to suppress the quantum tunneling effect, a moderate external dc field of 2000 Oe was applied to re‐measure the temperature‐dependent ac magnetic susceptibilities of 6 and 12 .…”

“…However, no obvious peaks were observed, which is possibly attributed to the quantum tunneling of the magnetization. [35] In order to suppress the quantum tunneling effect, a moderate external dc field of 2000 Oe was applied to re-measure the temperature-dependent ac magnetic susceptibilities of 6 and 12. Unfortunately, the frequency-dependent out-ofphase ( ′′) signals under 2000 Oe dc field are similar to these under zero dc field ( Figures S19 and S20).…”

Syntheses, Structures, and Magnetic Properties of Two Series of 3d–4f Heterometallic Coordination Polymers Derived from Pyrazine‐2,3‐dicarboxylic Acid

“…Unfortunately, no noticeable in‐phase ( χ′ ) or out‐of‐phase ( χ′′ ) signals are observed above 2 K (Figures S11 and S12), which can be attributed to quantum tunneling of the magnetization. An optimum external DC field of 2000 Oe was applied to reduce the quantum‐tunneling effect …”

Syntheses, Crystal Structures, and Magnetic Properties of a Series of Defect‐Dicubane Tetranickel(II) Systems with Variable, Mixed, and Interchangeable µ3‐Core Ligands

“…For tetrametallic clusters, one familiar motif is defect‐dicubane. It may be mentioned that there are a number of defect‐dicubane compounds having only 3d metal ions,[3b], [3c], [3d], [3e], [3f], [3g], only 4f metal ions[8e] and both 3d and 4f metal ions …”

“…The choice or design of ligands and self‐assembling[3h], [3i] are crucial for stabilizing clusters, , (as well as coordination polymers, CPs, ). The symmetric two‐compartmental Schiff base ligands (like H 3 L; two O(alcohol)N(imine)O(phenol) sites; Scheme ) that are obtained from [1+2] condensation of a 4‐R‐2,6‐diformylphenol (R = Me, Et, n ‐butyl, tert ‐butyl, Cl, CF 3 , etc.)…”