Construction of Designated Heptanuclear Metal 8-hydroxyquinolates with Different Ions and Auxiliary Coligands

Abstract

The series of metal 8-hydroxyquinolates {[Ni7 (μ2-L 1 )6­(μ3-L 1 )2(OAc)2­(μ7-L 2 )­(OCH3)]·CH3OH·CH3CN} (1), {[Ni7(μ2-L 1 )6­(μ3-L 1 )3­(SCN)2­(μ7-L 2 )­(CH3CN)]·(CH3OH)2·CH3CN} (2), [Ni5Dy2(μ2-L 1 )6­(OAc)4(μ7-L 2 )2] (3), [Ni6Dy­(μ2-L 1 )6­(μ3-L 1 )2(OAc)3­(μ7-L 2 )­(OCH3)] (4), and [Ni6Dy­(μ2-L 1 )6­(μ3-L 1 )2­(OAc)2­(NO3)­(OH)2­(OCH3)2] (5) (HL 1 = 8-hydroxyquinoline, H3 L 2 = 1,1,1-tris­(hydroxymethyl)­ethane) has been solvothermally prepared. Those clusters feature a heptanuclear disklike structure with 8-hydroxyquinolines as corner ligands restricting the expansion of the triangular lattice in spite of the metal ions or auxiliary coligands. The magnetic properties of those complexes vary according to metal ions and auxiliary coligands, for which slow magnetic relaxation is found in 5.

Superb Alkali-Resistant DyIII2NiII4 Single-Molecule Magnet

“…The Ni1···Ni2, Dy1···Ni1, Dy1···Ni2 and Dy1···Dy1A distances are 3.1173(7), 3.2443(4), 3.2524(4) and 5.3811(5) Å, respectively (Figure b). To the best of our knowledge, in comparison with the reported 8-hydroxyquinolinolate lanthanide complexes [hqH 2 ]­[Ln 2 (hq) 4 (NO 3 ) 3 ]·MeOH (Ln = Y, Tb, Dy, Ho, Er, Yb, Lu) and [Ln 3 (OQ) 9 ] (Ln = Gd, Tb, Dy) and the heterometallic complexes Ln 2 M­(OQ) 8 (Ln = Dy, Er; M = Ca, Mg), M 2 Dy­(L) 3 (OH)·2H 2 O (M = Cd, Co, Fe), M 2 Eu­(L) 3 (OH)·2H 2 O (M = Zn, Cd, Co, Ni), M 2 Ln­(L) 3 (OH)·2H 2 O (Ln = Tb, Sm; M = Zn, Co, Ni), M 2 Gd­(L) 3 (OH)·2H 2 O (M = Cd, Co, Ni), and [Ni 6 Dy­(μ 2 -L 1 ) 6 (μ 3 -L 1 ) 2 (OAc) 2 (NO 3 )­(OH) 2 (OCH 3 ) 2 ], 1 is the first hexanuclear 8-hydroxyquinolinolate heterometallic compound.…”

“…Similarly to the geometry of Ni1, Ni2 also has a six-coordinated environment, which is constructed by three O atoms (O1, O2 and O3) from three L − anions, one O atom (O5) from one CH 3 COO − anion, and two N atoms (N1 and N2) from two L − anions (Figure S1c). The Ni−O and Ni− N bond lengths are in the ranges of 2.013(2)−2.1525 (19) 10 1 is the first hexanuclear 8-hydroxyquinolinolate heterometallic compound.…”

“…According to the classic hard–soft acid–base (HSAB) theory, 4f metal ions are hard acids and easily coordinate with O atoms, while 3d metal ions such as Ni 2+ ions and Fe 2+ ions are borderline acids and exhibit strong affinity with both N and O atoms . Thus, to obtain 3d–4f heterometallic compounds, the choice of appropriate polydentate ligands (e.g., Schiff base, Mannich base, oxime and 8-hydroxyquinoline) possessing N and O atoms is viewed as the most effective synthetic strategy in all of the explored methods. − …”

LnIII/MnII–LnIII complexes derived from a salicylic azo dye ligand: synthesis, structures, magnetic and fluorescence properties

“…The azo ligand usually shows trans to cis photoisomerization and azo-hydrazone tautomerism under light irradiation, pH-control and metal-ion complexation. 29–32 In our previous studies, a series of lanthanide complexes based on azo ligands display SMM, fluorescence and photochromic properties. 33–35 To the best of our knowledge, heterometallic 3d–4f complexes, using the salicylaldehyde-based azo dye compound as a ligand, have not been reported up to now.…”

A Stable 3d–4f Heterometallic Cluster with Magneto-Optical Activity

“…Many bifunctional ligands with different electron-donating groups, such as −NH 2 , −Py (Py = Pyridyl), −OH, −COOH, −SO 3 , −PO 3 , and so on, are favorable structure-directing agents to integrate 3 d and 4 f metal ions into heterometallic clusters. − The employment of polydentate ligands containing both N and O donors for obtaining 3 d –4 f heterometallic products has attracted increasing attention due to the distinct affinity and/or preference of the 3 d and 4 f metal ions to N/O donors. − 8-Hydroxyquinoline, a naphthalene-like molecule containing both −N and −OH donors at positions 1 and 8, respectively, can serve as a bifunctional chelating ligand to integrate 3 d and 4 f ions to form hybrid structures. − …”