The reaction of 2-methoxy-6-(pyridin-2-ylhydrazonomethyl)phenol (LH) with Ln(III) (Ln = Gd, Tb, Dy, Ho) salts in the presence of an excess of triethylamine afforded [Gd4(L)4(μ4-OH)(μ3-OH)2(NO3)4]·(NO3)·4CH3CN·CH3OH·2H2O (1), [Tb4(L)4(μ4-OH)(μ3-OH)2(NO3)4]·(NO3)·4CH3CN·3H2O (2), [Dy4(L)4(μ4-OH)(μ3-OH)2(NO3)4]·(NO3)·6CH3CN·H2O (3), and [Ho4(L)4(μ4-OH)(μ-OH)2(NO3)4]·(NO3)·8CH3CN·3CH3OH·2H2O (4). All four complexes contain a monocationic tetranuclear core with a unique seesaw topology. The tetranuclear assembly is formed through the coordination of four [L](-), one μ4-OH, two μ3-OH, and four chelating nitrate ligands, with a charge-balancing nitrate counteranion. Magnetic studies reveal a weak antiferromagnetic coupling throughout the series. Compound 1 can be modeled well with an isotropic exchange between all centers parametrized by J = -0.09 cm(-1). Compound 3 exhibits slow magnetic relaxation at low temperatures.
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Dalton Trans
August 2023
Department of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland.
The linking of two dinuclear macrocyclic units of large triphenolic hexaazamine by two carbonate anions results in the formation of dimeric tetranuclear Sm(III), Eu(III) and Gd(III) complexes. These complexes were initially obtained serendipitously by fixation of atmospheric carbon dioxide and subsequently obtained in a rational way by the application of carbonate salts. The X-ray crystal structures of these isomorphic complexes show highly folded conformation of the macrocycle.
View Article and Find Full Text PDFACS Omega
June 2022
Beijing National Laboratory for Molecular Sciences, Center for Molecular Science, Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
It is challenging to use achiral ligands to spontaneously construct chiral molecular magnets. In this work, two new Ln cluster complexes based on ,'-(1,3-propanediyl)bis[-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]amine] (HL) have been assembled, which are crystallized in a chiral space group due to the asymmetric distribution of acetate (OAc) groups and hexafluoroacetylacetonate (Facac) groups on both sides of the parallelogram-like Ln core. Complex , [Dy(HL)(OAc)(Facac)]·5MeOH·2HO, exhibits single-molecule magnet properties at the zero field with the / value of 48.
View Article and Find Full Text PDFDalton Trans
September 2021
N.S. Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninsky prosp. 31, Moscow 119991, Russia.
Two series of heterometallic Ln-Cu compounds containing a butterfly-like tetranuclear metal core were synthesized and characterized by X-ray diffraction and magnetometry. The structures of the new compounds were shown to depend on the nature of the hydroxide used for the synthesis. The reactions of copper(II) and lanthanide(III) salts with Hpiv (Hpiv is trimethylacetic acid) and LiOH in a MeCN-EtOH mixture afford the molecular complexes [LnCu(μ-OH)(piv)(HO)]·4EtOH (1Ln, Ln = Gd, Tb, Dy, Ho, Yb), whereas the similar reactions using NaOH instead of LiOH give the 1D coordination polymers [NaLnCu(μ-OH)(piv)(EtOH)]·EtOH (2Ln, Ln = Gd, Tb, Dy, Ho, Yb).
View Article and Find Full Text PDFInorg Chem
June 2018
Department of Applied Biology and Chemical Technology , The Hong Kong Polytechnic University, Hung Hom , Kowloon 999077 , Hong Kong.
Discrete lanthanide(III) tetranuclear cubane-like clusters seldom occur throughout the Ln series and behave as single-molecule magnets (SMMs). Herein, a series of cubanes, [Ln(μ-OH)(μ-tfa)(hfa)(phen)] (1-9, Ln = La-Dy (except Pm), tfa = trifluoroacetate, hfa = hexafluoroacetylacetonate, phen = 1,10-phenanthroline), and dinuclear clusters, [Ln(μ-OH)(hfa)(phen)] (10-16, Ln = Tb-Lu), were synthesized and characterized. Two types of clusters were formed due to the change of preferred coordination geometry for lighter and heavier Ln ions which favor nine-coordinated cubanes and eight-coordinated dimers, respectively.
View Article and Find Full Text PDFDalton Trans
May 2018
Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 1-7 Gh. Polizu Street, 011061 Bucharest, Romania.
A new series of {FeIII2LnIII2} heterobimetallic squares of general formula [FeIII{HB(pz)3}(CN)(μ-CN)2Ln(pyim)x(NO3)2(H2O)y]2·zH2O [Ln = La (1), Gd (2), Tb (3) and Dy (4); {HB(pz)3}- = hydrotris(pyrazolyl)borate and pyim = 2-(1H-imidazol-2-yl)pyridine; x = 2, y = 0 (1), x = y = 1 (2-4) and z = 10 (1), 6 (2), 2.76 (3), 4 (4)] were synthesized by reacting the low-spin [FeIII{HB(pz)3}(CN)3]- complex anion with the preformed [LnIII(pyim)x(NO3)2(H2O)y]+ complex cation [formed in situ by mixing the lanthanide(iii) salt and the pyim ligand]. Single-crystal X-ray diffraction shows that 1-4 crystallize in the P1[combining macron] triclinic space group, 2-4 being isomorphous.
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