0000000001311484
AUTHOR
Angeliki A. Athanasopoulou
Metallacrown Complexes Reaching the Nanosize Regime
Abstract The chapter discusses the merit of metallacrown complexes to achieve multifunctional and multidimensional molecular materials. It introduces basic design strategies for discrete metallacrown complexes and discusses the predictability of molecular properties. Thereafter, it reviews two of the most outstanding molecular properties of metallacrown complexes, namely, the magnetic and luminescence characteristics. Most interestingly, for metallacrown complexes, such properties could be combined in one single molecule, giving rise to stable “multifunctional” molecular materials. Moreover, MCs are suitable building blocks to construct multidimensional coordination polymers. The chapter pr…
Element-specific magnetic properties of mixed 3d−4f metallacrowns
Single molecule magnets comprising rare earth metals are of high interest due to the unquenched orbital moments of the rare earth ions that result in a large energy barrier for magnetization reversal. We investigate the magnetic properties of polynuclear $3d\text{\ensuremath{-}}4f15$-MC-5 metallacrowns using x-ray magnetic circular dichroism of powder samples at a temperature of 7 K in a magnetic field of 7 T. The sum rule analysis reveals element-specific spin and orbital moments. The magnetic moments of the $3d$ transition metal Ni(II) ions are coupled antiferromagnetically to each other and contribute only little to the total molecular moment. The spin and orbital moments of the rare ear…
Slow relaxation of magnetization in a {Fe6Dy} complex deriving from a family of highly symmetric metallacryptands
The synthesis and characterization of a new family of isostructural {Fe6Ln} complexes, (pipH)3{Fe6Ln(shiH)3(shi)6}·1.5 pip·xH2O (Ln = Gd (1), Dy (2), Tb (3) and Y (4), pip = piperidine, and shi3− = salicylhydroxamic acid) is reported. The resulting compounds possess an exceptionally unique structure of a metallacrown-like motif while the overall complexes feature more the structure of metallacryptates. Magnetic studies are reported and reveal that the {Fe6Dy} analogue belongs to the single-molecule magnet (SMM) family.
Field-Induced Slow Magnetic Relaxation In the First Dy(III)-centered 12-Metallacrown-4 Double-Decker
The reaction of Dy(O2CMe)3·xH2O and Ga(NO3)3·xH2O led to the isolation of (nBu4N)[GaIII8DyIII(OH)4(shi)8] (1). The compound possesses a unique chemical structure enclosing the central magnetic DyIII ion between diamagnetic GaIII-based metallacrown 12-MC-4 ligands. The double-decker complex exhibits field-induced single-molecule magnet (SMM) behaviour with an effective energy barrier (Ueff) of 39 K (27.1 cm−1). Consistent with the observed slow relaxation of magnetization, theoretical calculations suggest a ground state mainly determined by |±11/2> in the easy axis direction.
CCDC 1873577: Experimental Crystal Structure Determination
Related Article: Angeliki A. Athanasopoulou, Luca M. Carrella, Eva Rentschler|2019|Dalton Trans.|48|4779|doi:10.1039/C9DT00552H
CCDC 1873578: Experimental Crystal Structure Determination
Related Article: Angeliki A. Athanasopoulou, Luca M. Carrella, Eva Rentschler|2019|Dalton Trans.|48|4779|doi:10.1039/C9DT00552H
CCDC 1903450: Experimental Crystal Structure Determination
Related Article: Angeliki A. Athanasopoulou, José J. Baldoví, Luca M. Carrella, Eva Rentschler|2019|Dalton Trans.|48|15381|doi:10.1039/C9DT02432H
CCDC 1873576: Experimental Crystal Structure Determination
Related Article: Angeliki A. Athanasopoulou, Luca M. Carrella, Eva Rentschler|2019|Dalton Trans.|48|4779|doi:10.1039/C9DT00552H
CCDC 1873575: Experimental Crystal Structure Determination
Related Article: Angeliki A. Athanasopoulou, Luca M. Carrella, Eva Rentschler|2019|Dalton Trans.|48|4779|doi:10.1039/C9DT00552H