A simple methodology for constructing ferromagnetically coupled Cr(iii) compounds

Abstract

A large family of chromium(III) dimers has been synthesised and magneto-structurally characterised using a combination of carboxylate and diethanolamine type ligands. The compounds have the general formula . Removal of the carboxylate to produce the dialkoxide-bridged compound 9 resulted in antiferromagnetic (AFM) exchange between the Cr(III) ions. DFT calculations reveal the ferromagnetic exchange is the result of an orbital counter-complementarity effect occuring upon introduction of the bridging carboxylate.

An [FeIII34] Molecular Metal Oxide

“…In order to estimate the magnitude of the magnetic exchange interactions in 1 we have employed a DFT methodology (B3LYP/TZVP) known to yield excellent numerical estimates of J values . Calculations were performed using the model structures shown in Figures S8–S12 (see the computational details in the Supporting Information for discussion).…”

Pentanuclear Spirocyclic Ni4Ln Derivatives: Field Induced Slow Magnetic Relaxation in the Dysprosium and Erbium Analogues

“…3d and 4f metal ions in a same compound is not a trivial task. Chemists have to devise appropriate organic ligands with specific functionalities for preferential aggregation of both 3d and 4f metal ions, at the same time where magnetic exchanges can occur among the metal centres via a suitable single‐atom or by means of multiatom bridges . Based on the above requirements in mind we prepared a new chelating, multisite, coordinating Schiff base ligand ( E )‐2‐(hydroxymethyl)‐6‐{[(2‐hydroxyphenyl)‐imino] methyl}‐4‐methylphenol (LH 3 ), leading to the formation of heterometallic 3d/4f complexes.…”

An [FeIII34] Molecular Metal Oxide

“…In order to estimate the magnetic exchange interactions in 1 we have employed a DFT methodology (B3LYP/TZVP) known to yield excellent numerical estimates of J values. [12], [13], [14], [15] Calculations were performed using the model structures shown in Figures S9-S13 (see computational details in ESI for discussion). The symmetric nature of the cage reduces the number of unique exchange interactions to five, describing those between: (i) inner tetrahedral Fe(III) ions (J1) connected by µ3-O 2ions; (ii) inner tetrahedral and outer octahedral Fe(III) ions (J2) connected by µ3/µ4-O 2ions; (iii) outer octahedral Fe(III) ions (J3) connected by µ3-O 2ions; (iv) outer tetrahedral Fe(III) ions (J4) connected by µ3-O 2ions; and (v) outer tetrahedral and outer octahedral Fe(III) ions (J5) connected by µ3-O 2ions (Scheme S1).…”