Syntheses, structures and magnetic properties of a family of one-dimensional M(II)-lanthanide(III) (M = Ni(II) and Zn(II)) coordination polymers

Abstract

A series of 1D nickel(II)/zinc(II)-lanthanide(III) coordination polymers, [M(μ-L) 2 Ln(NO 3 ) 3 ] n ·solvents (HL = bis(2-pyridylcarbonyl)amine; M = Ni, Ln = Gd (1·NiGd), Tb (2·NiTb), Dy (3·NiDy), Ho (4·NiHo), Y (5·NiY); M = Zn, Ln = Gd (6·ZnGd), Tb (7·ZnTb), Dy (8·ZnDy), Ho (9·ZnHo); solvents = H 2 O or H 2 O-ethanol), was synthesized and characterized. All of the complexes are isostructural at 293 K and crystallize in the orthorhombic space group Fddd. Magnetic measurements were performed on 1-9, where weak ferromagnetic interaction is found in 1·NiGd, ferromagnetic interaction in 2·NiTb and 3·NiDy, and antiferromagnetic interaction in 4·NiHo. A remarkable dc magnetic field dependence of ac susceptibilities was found in this series of complexes.nickel, lanthanide, 3d-4f coordination polymer, magnetic property Molecule-based magnetic materials have attracted increasing attention in recent years due to their significance in fundamental research and potential applications in molecular devices [1][2][3][4] . In the process of exploring novel molecular magnetic materials, the nature and spatial arrangement of the spin carriers are two of the most decisive factors to determine the magnetic behaviors of the resulting materials [5][6][7] . This is especially true in the constructions of single-molecule magnets (SMMs) [8] and single-chain magnets (SCMs) [9] , in both of which a high spin ground state (S ) and a large and negative axial zero-field splitting (D < 0) of that ground state are required.Paramagnetic lanthanide ions have begun to be adopted in the field of molecule-based magnetic materials because most of them can exhibit large anisotropic magnetic moments, which are required by magnetically ordered materials with large coercive fields [10] . Up to now, the incorporation of lanthanide ions with 3d metal ions (i.e., 3d-4f complexes) or radicals have resulted in various heteronuclear complexes exhibiting interesting magnetic behaviors, such as SMMs and SCMs [11][12][13][14][15][16][17][18][19][20][21] . The idea of incorporation of lanthanide ions into 3d-4f chain complexes opens a new way to build novel SCMs, though the rational design and synthesis of extended structures of coordination polymers are still a challenge.The multi-dentate ligand bis(2-pyridylcarbonyl)amine (HL) has long been used as a tridentate N ligand to form mononuclear complex [M(L) 2 ] [22,23] . The four free carbonyl C-O groups in the resulting [M(L) 2 ] can further participate in coordination with metal ions, through which [M(L) 2 ] acts as a bis-bidentate bridging complex ligand to afford polynuclear [24][25][26] and multi-dimensional

3d−4f Combined Chemistry: Synthetic Strategies and Magnetic Properties

“…The symmetry of the lanthanide polyhedron plays also an important role . Interestingly, the slight modification of the crystallization procedure, by changing the solvents, leads to other types of chains (wavelike instead of linear), with all of the nitrato groups coordinated to the lanthanide cations: [{Ln(O 2 NO) 3 }{Ni(bpca) 2 }]· n H 2 O (Ln = Gd, Tb, n = 6.5; Ln = Dy, Ho, n = 5.5) . The magnetic measurements revealed negligible interactions for the gadolinium derivative, weak ferromagnetic interactions for [NiTb] and [NiDy], and weak antiferromagnetic interactions for [NiHo].…”

Metallo‐Ligand Based 3d/4f Coordination Polymers: Synthesis, Structure and Magnetic Properties

“…[36][37][38][39][40][41][42][43][44][45] Nevertheless, there have been several reports of polymeric 3d/4f species obtained by the so called "metal complex as ligand" strategy, where a pre-isolated metal complex serves as a "metalloligand". [46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61] This strategy is based on ligands with usually N and O donor atoms on their inner shell and N or O atoms on their outer shell. Such organic ligands form a discrete, usually a mononuclear, metal complex with a 3d metal ion such as Cu 2 + , Ni 2 + or Co 2 + that has uncoordinated N or O donor atoms on its periphery where other metal ions such as lanthanides coordinate to form polymeric species.…”

“…Polymeric 3d/4f complexes have also been isolated by such an in situ synthesis [36–45] . Nevertheless, there have been several reports of polymeric 3d/4f species obtained by the so called “metal complex as ligand” strategy, where a pre‐isolated metal complex serves as a “metallo‐ligand” [46–61] . This strategy is based on ligands with usually N and O donor atoms on their inner shell and N or O atoms on their outer shell.…”

Synthesis, crystal structures and magnetic properties of two three-dimensional heterotrimetallic compounds [Cu(en)2Li(H2O)][Fe(CN)6] and [Cu(en)2Li(H2O)][Co(CN)6] (en = ethylenediamine)

“…This strategy has been properly used in the magnetic studies of 3d-4f complexes as an empirical approach to qualitatively analyze the type of magnetic interaction between the metal centers [31][32][33][34][35][36][37]. In our case, two analogues, i.e., 2 (Co(III)-Cu(II)) and Fe(III)-Zn(II), should be synthesized for such an analysis.…”