3d/4f Sandwich Complex Based on Metallacrowns

Abstract

A novel lanthanide double-decker complex with nickel metallacrowns (MCs) as coordinating ligands has been synthesized. In the 3d/4f metallacrown complex TbIII[12-MCNiIIN(shi)-4]2, the central lanthanide ion is sandwiched between two [12-MC-4] units, forming an almost ideal square-antiprismatic coordination sphere. The resulting zenithal angles at the central lanthanide ion are smaller than those for previously reported sandwich compounds. Magnetic measurements reveal an energy barrier of 346 K under zero field and up to 585 K under 3200 Oe, the highest reported for metallacrowns with D 4d symmetry.

Synergistic Experimental and Theoretical Studies of Luminescent–Magnetic Ln2Zn6 Clusters

“…Optimization of the desired physiochemical properties of value-added products using various nonconventional strategies remains the primary motive of researchers working on exploratory inorganic functional materials. − In a nutshell, unlike the purist inorganic chemists’ approach of solving a mystery with orthodox methods, excelling materialistic properties of commercial importance are at the heart of these types of scientific endeavors. − Interestingly, most of the physiochemical features of inorganic compounds are strongly related to the electronic and magnetic interactions in terms of their valence orbital overlap of either among the metal centers or between the metal center and the functional moiety of coordinating organic ligands. − Naturally, any judicious plan aiming to boost the utility of the compound should put more emphasis on enhancing the interactions among the related functional orbitals …”

“…One such prime example would be 3d–4f mixed-metal complexes. − Notwithstanding the initial skepticism, the concomitant presence of transition metals and lanthanides for the construction of a polynuclear cage and clusters has proven to be highly rewarding, with markedly improved magnetic, chemical, optical, and other physical properties. − Of particular interest is the deliberate mixing of f and d electrons to induce stronger interactions vis-a-vis individual d–d or f–f electrons to transcend the magnetic, electronic, and optical properties, and their mutual interplay is now well documented. , Subsequently, the last few decades have witnessed a phenomenal upsurge of interest in studies of mixed-metal complexes. , Almost every possible combination of 3d–4f complexes has been explored. − The emphasis of initial works is more or less “one-dimensional”; that is, they aim to optimize one particular property like magnetism or optics. − With advancement of the subject, however, other potential uses of these complexes soon become increasingly apparent . Moreover, instead of using randomly chosen pairs, a specific combination of 3d and 4f metals with the aim of culminating their characteristic properties starts to dominate the design strategy, aiming to kill two birds with one stone .…”

Insight into ferromagnetic interactions in CuII–LnIII dimers with a compartmental ligand

“…[18][19][20][21] Furthermore, Matsumoto and co-workers successfully synthesized the first 3d-4f SMM complex [Cu II Tb III L 1 (hfac) 2 ] 2 (H 3 L 1 = 1-(2-hydroxybenzamido)-2-(2hydroxy-3-methoxy-benzylideneamino)-ethane), in which the magnetic interaction between Cu II and Tb III ions has been proven to be critical for its SMM behaviour, 22 and thereafter, the 3d-4f system is found to be increasingly important owing to its promising applications in quantum storage and spintronic devices. [23][24][25][26][27][28] The preparation of complexes containing only a limited number of 3d and 4f ions is crucial, particularly when the study is focused on gaining an in-depth understanding of the 3d-4f magnetic interactions. In such a case, the automatic choice is a simple heterobimetallic 3d-4f complex, well isolated from its congeners.…”

“…18–21 Furthermore, Matsumoto and co-workers successfully synthesized the first 3d–4f SMM complex [Cu II Tb III L 1 (hfac) 2 ] 2 (H 3 L 1 = 1-(2-hydroxybenzamido)-2-(2-hydroxy-3-methoxy-benzylideneamino)-ethane), in which the magnetic interaction between Cu II and Tb III ions has been proven to be critical for its SMM behaviour, 22 and thereafter, the 3d–4f system is found to be increasingly important owing to its promising applications in quantum storage and spintronic devices. 23–28…”

Single‐ vs Double‐Decker Copper 12‐MC‐4 Metallacrown Using the Coordination Flexibility of a Soft Donor Ligand

“…Since metallacrowns (MC) were first introduced in 1989 by Pecoraro, they have been of great interest in various fields of research including molecular recognition, host-guest chemistry, catalysis, magnetism and luminescence. [1][2][3][4][5][6] Like their organic analogues crown ethers MC have À [MÀ NÀ O] n -repeating units of metal ions, nitrogen and oxygen atoms leading to different ring sizes and enabling MC to coordinate guest metal ions. The most common crown types are 9-MC-3, 12-MC-4 and 15-MC-5.…”