Abstract: В ТЕЗИСАХ 2 БЛАГОДАРНОСТИ. Stable oxazolidine nitroxyl radicals (ONRs) functionalized with coordinating heterocycles are promising in the design of molecular magnetic materials because they have a predictable way of coordination. This is particularly relevant for obtaining low-coordination magneto-anisotropic trivalent lanthanide complexes with controlled uniaxial symmetry and ligand field strength around the central Ln ion, which is essential to suppress under barrier magnetization tunnelling in SMM. Moreover, our previous studies of a series of monoradical [LnRad(NO3)3] (1) complexes [1] have unveiled the presence of a sufficiently strong magnetic exchange interaction between ONR and Ln, which should also contribute to the suppression of the tunnelling effect. Magnetization tunnelling is the greater than the lower the symmetry of the coordination sphere, is characteristic of coordination-capacious lanthanides. For this reason, the design of paramagnetic ligands to create complexes with coordination sphere geometries suitable for either prolate-type or oblate-type of Ln3+ ions is a challenging task. As it turned out, [Ln(Rad)2(OTf)3] (2) - biradical sandwich-like complexes (Fig. 1) have bent character structure. Triflate ligands in the equatorial plane of 2 are well suited for the oblate type Ln3+ ions, while their absence is more appropriate for the prolate ones. To fine-tuning the geometry and composition of the coordination sphere of complexes 2 for both types of metal ions, the Rad-ligand should be more symmetrical. On the other side, in order to prevent coordination of either anionic ligands or solvent molecules at the equator, it is necessary to use the sterically more demanded radical. The report presents approaches for solving these problems. Figure 1. [Ln(Rad)2(OTf)3] [2]. [1] M. Perfetti, A. Caneschi, T.S. Sukhikh and K.E. Vostrikova Inorg. Chem., 2020, 59, 16591. [2] P. Rey, A. Caneschi, T.S. Sukhikh and K.E. Vostrikova. Inorganics 2021, 9, 91.

Cite: Vostrikova K.E.
Rational design of the Ln3+ complexes with tripodal nitroxyl radicals
HIGH-SPIN MOLECULES AND MOLECULAR MAGNETS 09-14 Jul 2023