ИСТИНА

Acylpyrazolonate ligands were extensively used for the preparation of variety of complexes with d-elements and selected lanthanides [1]. Two main type of complexes with lanthanides were obtained for these ligands – neutral tris complexes (I) and anionic tetrakis complexes (II), bearing cation on the outer sphere of complex. In some cases free acids with H3O+ or (H5O2) + cations were isolated. The coordination polyhedron for Ln3+ in tetrakis complexes is represent by perfect square antiprism, and such environment is favorable for manifestation of SMM properties. Unfortunately, known synthetic pathways to these complexes are unreliable and often led to unpredictable result. We have investigated complicated temperature-depended equilibrium between tris and tetakis species in solutions and elaborated direct pathways to both types of complexes. Besides, some aspects of crystal structures and luminescent properties of lanthanide complexes with different composition will be discussed in the presentation. [1] C. Pettinari, F. Marchetti and A. Drozdov, in Comprehensive Coordination Chemistry II, ed. J. A. McCleverty and T.J. Meyer, Elsevier, 2003, 97-139. Acknowledgements We are grateful to the Russian Science Foundation (grant No.19-13-00272) and Russian Fund for Basic Research (grant No. 18-02-00653) for financial support.