Heterometallic MIILnIII (M = Co/Zn; Ln = Dy/Y) Complexes with Pentagonal Bipyramidal 3d Centers: Syntheses, Structures, and Magnetic Properties

Fu-Xing Shen; Hong-Qing Li; Hao Miao; Dong Shao; Xiao-Qin Wei; Le Shi; Yi-Quan Zhang; Xin-Yi Wang

doi:10.1021/acs.inorgchem.8b02875

Heterometallic M^IILn^III (M = Co/Zn; Ln = Dy/Y) Complexes with Pentagonal Bipyramidal 3d Centers: Syntheses, Structures, and Magnetic Properties

Inorg Chem. 2018 Dec 17;57(24):15526-15536. doi: 10.1021/acs.inorgchem.8b02875. Epub 2018 Nov 30.

Authors

Fu-Xing Shen¹, Hong-Qing Li¹, Hao Miao¹, Dong Shao¹, Xiao-Qin Wei¹, Le Shi¹, Yi-Quan Zhang², Xin-Yi Wang¹

Affiliations

¹ State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , China.
² Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology , Nanjing Normal University , Nanjing 210023 , China.

PMID: 30500167
DOI: 10.1021/acs.inorgchem.8b02875

Abstract

We herein reported the syntheses, structures, and magnetic properties of three dinuclear heterometallic M^IILn^III complexes, namely, [M^IILn^III(H₂L)(CH₃OH)₂(NO₃)₂](NO₃)·S (M = Co, Ln = Dy, S = MeOH (1_CoDy); M = Zn, Ln = Dy, S = MeOH (2_ZnDy); M = Co, Ln = Y, S = MeNO₂ (3_CoY), H₄L = 2,6-diacetylpyridine bis[2-(semicarbazono) propionylhydrazone]. Synthesized from the predesigned multidentate ligand H₄L, which has two different coordination pockets (smaller N₃O₂ and larger N₂O₄ pockets) suitable for either a 3d or a 4f metal center, all these complexes have very similar structures, where the M^II centers possess a pentagonal bipyramidal (PBP) geometry and the Ln^III sites have a tetradecahedron geometry. Magnetic measurements on these compounds revealed the existence of weak ferromagnetic coupling between the Co²⁺ and Dy³⁺ centers and the field-induced slow magnetic relaxation of all three complexes. Furthermore, theoretical calculation on all these complexes indicates that although the change of the diamagnetic Zn²⁺ ion to the paramagnetic Co²⁺ ion only slightly modifies the local magnetic anisotropy of the Dy³⁺ ion, the weak Co-Dy magnetic interaction decreases the energy barrier. These compounds are the first systematic results of a heterometallic 3d-4f single-molecule magnet containing predesigned PBP 3d metal ions.