A Ferromagnetically Coupled, Bell-Shaped [Ni4Gd5] Cage

Foteini E Kakaroni; Demetrios I Tzimopoulos; Hector W L Fraser; Milosz Siczek; Tadeusz Lis; Marco Evangelisti; Euan K Brechin; Constantinos J Milios

doi:10.1021/acs.inorgchem.9b00946

A Ferromagnetically Coupled, Bell-Shaped [Ni₄Gd₅] Cage

Inorg Chem. 2019 Sep 3;58(17):11404-11409. doi: 10.1021/acs.inorgchem.9b00946. Epub 2019 Aug 15.

Authors

Foteini E Kakaroni¹, Demetrios I Tzimopoulos², Hector W L Fraser³, Milosz Siczek⁴, Tadeusz Lis⁴, Marco Evangelisti⁵, Euan K Brechin³, Constantinos J Milios¹

Affiliations

¹ Department of Chemistry , The University of Crete , Voutes , 71003 Herakleion , Greece.
² Department of Chemistry , Aristotle University of Thessaloniki , 54124 Thessaloniki , Greece.
³ EaStCHEM School of Chemistry , The University of Edinburgh , David Brewster Road , Edinburgh EH9 3FJ , U.K.
⁴ Department of Chemistry , University of Wroclaw , 50-283 Wroclaw , Poland.
⁵ Instituto de Ciencia de Materiales de Aragón (ICMA) , CSIC-Universidad de Zaragoza , 50009 Zaragoza , Spain.

PMID: 31414600
DOI: 10.1021/acs.inorgchem.9b00946

Abstract

Reaction between NiCl₂·6H₂O, 2-hydroxy-4-methyl-6-phenyl-pyridine-3-amidoxime (H₂L), benzoic acid, and M(NO₃)₃·6H₂O (M = Gd, Y) in MeCN under basic conditions yields the complexes [Ni^II₄Gd^III₅(PhCOO)₁₀(HL)₄(HL_zw)₄(OH)₂(NO₃)₂]Cl·13.6MeCN·H₂O (1·13.6MeCN·H₂O) and [Ni^II₄Y^III₅(PhCOO)₁₀(HL)₄(HL_zw)₄(OH)₂(NO₃)_1.5(H₂O)_0.5]0.5Cl(NO₃)·3H₂O (2·3H₂O). Both clusters display similar structures, consisting of a bell-shaped {Ni^II₄M^III₅} unit, in which a linear "zigzag" {Ni₄} subunit bisects the central {M^III₅} "ring". Direct (dc) and alternating current (ac) magnetic susceptibility measurements carried out in the 2-300 K temperature range for complexes 1 and 2 revealed ferromagnetic intermolecular interactions, while heat-capacity measurements for the Gd analogue suggest that complex 1 lowers its temperature from T = 9.6 K down to 2.3 K by adiabatically demagnetizing from B_i = 7 T to B_f = 0.