A flexible iron(ii) complex in which zero-field splitting is resistant to structural variation

Abstract

The zero-field splitting parameters D and E in the iron(ii) complex [Fe(C3S5)2]2– are shown to be remarkably resistant to a twist of the inter-ligand dihedral angle (θd) from 90 to 70°.

Role of Coordination Number and Geometry in Controlling the Magnetic Anisotropy in FeII, CoII, and NiII Single‐Ion Magnets

“…Although no ab initio analysis has been carried out in this work, the positive D in complex 64 may be attributed to the different orbital splitting, and also it is four‐coordinate rather than three‐coordinate as in complex 63 . Four‐coordinate Fe II SIMs have been thoroughly investigated by us and others to probe the origin of magnetic anisotropy [53, 63] . It was found that both positive and negative D values can be obtained in four‐coordination Fe II systems depending on the dihedral or interplanar angle.…”

Rotaxane CoII Complexes as Field-Induced Single-Ion Magnets

“…Tailoring the size and sign of D therefore represents a promising strategy to design molecules with a large U. 33 Single-ion magnets (SIMs) containing only one metal center are of particular interest due to the possibility of predicting anisotropy based on ligand field theory. 34,35 However, most transition-metal SIMs are still discovered serendipitously, at least in part both because D relies on subtle geometric effects and accurately predicting a priori the geometry or even stoichiometry of heteroleptic complexes formed from a mixture of ligands remains challenging.…”

Transformation of the coordination complex [Co(C3S5)2]2− from a molecular magnet to a potential qubit

“…While there is ample literature concerning maximizing D , and thus the spin reversal barrier ( U = DS 2 ), considerably fewer reports are devoted to understanding the rational tuning of E through ligand field variations. 9 , 10 A large body of literature in particular exists on magneto-structural correlations in systems with large, negative D values. Yet, in such systems it is very difficult to probe E spectroscopically or magnetically.…”