Nitronyl nitroxide–metal complexes as metallo-ligands for the construction of hetero-tri-spin (2p–3d–4f) chains

Abstract

A novel approach for the preparation of hetero-tri-spin magnetic compounds is described. It consists in using preformed metal-nitronyl nitroxide complexes as metallo-ligands in an assembling process involving an additional metal centre. This is illustrated by two unprecedented radical-Cu-Ln chain compounds (Ln = Gd(3+), Tb(3+)).

2p–3d–4f hetero-tri-spin molecule-based magnetic compounds

“…Moreover, these NO units also carry the unpaired electron which leads to strong magnetic exchange coupling with the paramagnetic metal ions to which they bind. 30 The synthetic approach consisted of using preformed Ln-nitronyl nitroxide complexes as metallo-ligands toward Cu(hfac) 2 . 28 More recently, 1D assembly of anisotropic 4f or Co(II) ions with nitronyl nitroxides attracted interest in relation to SCM behavior.…”

Analysis of the Magnetic Exchange Interactions in Yttrium(III) Complexes Containing Nitronyl Nitroxide Radicals

“…In these architectures, significant magnetic coupling can be observed that induces 0-, 1-, 2-or 3-dimensional overall magnetic behaviors. [25][26][27][28][29][30][31][32][33] Such materials can also give rise to unique magnetic behavior such as next-nearest neighbor interactions, 34 one-dimensional helimagnetism [35][36][37] or Single…”

Hetero‐tri‐spin [2p‐3d‐4f] Chain Compounds Based on Nitronyl Nitroxide Lanthanide Metallo‐Ligands: Synthesis, Structure, and Magnetic Properties

“…For these, the moiety bearing the unpaired electron directly coordinates to the metal ion leading thus to the strongest possible exchange interaction. [11] In an extension of this work, we have investigated the effect of chemical changes at periphery of the radical molecule on the assembling process as well as on the magnetic features of the resulting chain compounds. An illustration of it was given by a series of nitronyl nitroxide-lanthanide 1D compounds featuring different relaxation features.…”

“…A total of eleven novel 1D compounds, namely [Ln 3 Cu(hfac) 11 (NitPhOAll) 4 ] (Ln III = Gd, 1 Gd ; Tb, 1 Tb ; Dy, 1 Dy and hfac = hexafluoroacetylacetonate), [Ln 3 Cu(hfac) 11 -(NitPhOPr) 4 ] (Ln III = Gd, 2 Gd ; Tb, 2 Tb ; Dy, 2 Dy ; Ho, 2 Ho ; Yb, 2 Yb ), and [Ln 3 Cu(hfac) 11 (NitPhOBz) 4 ] (Ln III = Gd, 3 Gd ; Tb, 3 Tb ; Dy, 3 Dy ), have been investigated. We report on three families of chains of general formula [{Ln(hfac) 3 } 3 {Cu(hfac) 2 }(NitPhOR) 4 ] (Nit stands for nitronyl nitroxide, that is, 4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide, and R groups are allyl, propyl, and benzyl, respectively) that all exhibit the same assembling motif but differ by the radical molecules.…”