Synthesis, crystal structures and magnetic properties of two Ni-Dy heterometallic complexes with the structural topologies regulated by employing different Schiff base ligands

Synthesis, crystal structure and magnetic properties of octanuclear Ni4Ln4 complexes constructed using a Schiff base ligand and di-2-pyridyl ketone

“…Recently, we reported Ni 2 Dy and Ni 2 Dy 2 complexes by employing 2-[(2-hydroxyethylimino)methyl]-6-methoxyphenol (H 2 hmmp) or 2-(((2-hydroxy-3-methoxyphenyl)methylene)amino)-2-(hydroxymethyl)-1,3-propanediol (H 4 L) with dpk reacting with Ni and Dy salts. 27 However, only Ni 2 Dy results in the tails of out-of-phase ac susceptibility ( χ ′′) signals, but the peaks of χ ′′ are not present. 27 To obtain Ni–Dy complexes with higher SMM performance, we herein employ N -3-methoxysalicylidene-2-amino-3-hydroxypyridine (H 2 L) ligand and dpk for constructing Ni–Dy complexes.…”

“…Recently, we concentrated on the regulation of the structural topologies and magnetic relaxation behavior of 3d and 3d-Dy SMMs by employing two kinds of organic ligands, in which one type is Schiff base ligands, while the other ligands are common commercial organic ligands containing N and/or O atoms (auxiliary ligands), such as di-2-pyridyl ketone (dpk), triethanolamine (teaH 3 ), 2,6-pyridinedimethanol (pdmH 2 ). 14,19,27,[42][43][44]53,54 The auxiliary ligands were also usually employed for constructing polynuclear 3d SMMs and 3d-Dy SMMs by us and other research groups. 19,27,[42][43][44][53][54][55][56] Moreover, volumes of the auxiliary ligands are smaller than that of Schiff base ligands.…”

“…14,19,27,[42][43][44]53,54 The auxiliary ligands were also usually employed for constructing polynuclear 3d SMMs and 3d-Dy SMMs by us and other research groups. 19,27,[42][43][44][53][54][55][56] Moreover, volumes of the auxiliary ligands are smaller than that of Schiff base ligands. Therefore, two kinds of ligands can synergistically construct polynuclear 3d-Dy SMMs, with the topologies and magnetic relaxation regulated compared to SMMs with unitary ligands.…”

“…We believe this synthetic strategy is an effective method for the regulation of the topologies and magnetic properties of 3d and 3d-4f SMMs because most of the obtained complexes possess SMM properties. So far, many Mn-Dy, 53 Fe-Dy, 42,43 Co-Dy, 44 Cu-Dy 54 and Zn-Dy 19 27 However, only Ni 2 Dy results in the tails of out-ofphase ac susceptibility (w 00 ) signals, but the peaks of w 00 are not present. 27 To obtain Ni-Dy complexes with higher SMM performance, we herein employ N-3-methoxysalicylidene-2-amino-3-hydroxypyridine (H 2 L) ligand and dpk for constructing Ni-Dy complexes.…”

“…[19][20][21][22][23][24][25] Among the 3d metal ions, Ni II might be one of the better candidates for constructing SMMs because it often possesses a large single-ion zero-field splitting. Up to now, many Ni-Dy heterometallic complexes with different nuclearities like NiDy, 26 Ni 2 Dy, 27 Ni 2 Dy 2 , [28][29][30] Ni 3 Dy, 31 Ni 4 Dy 2 , 32 Ni 4 Dy 4 , 33 and Ni 8 Dy 4 , 34 and other high-nuclearity Ni-Dy 35 have been reported. Surprisingly, the highest U eff value for these reported Ni-Dy complexes is about 100 K, 29 which is much lower than the values of other 3d-Dy SMMs, such as Fe-Dy, 36 Co III -Dy SMMs, 37 Cu-Dy SMMs 38 and Zn-Dy SMMs.…”