Modulating the structural topologies from star-shape to cross-shape for Co–Dy heterometallic complexes with slow magnetic relaxation behavior

Abstract

Two novel Co-Dy heterometallic complexes, namely, [CoIII2DyIII2(HL)L{(py)2CO2}{(py)2C(OCH3)O}(NO3)4CH3OH]·2CH3CN·2.5H2O (1, H3L = 2-((2-hydroxy-benzylidene)amino)propane-1,3-diol, (py)2C(OH)2 = the gem-diol form of di-2-pyridyl ketone (dpk) and (py)2C(OCH3)OH = the hemiacetal form of dpk) and [CoIII{(py)2C(OH)O}2][CoII2CoIII4DyIII(HL)4(L)4]·3CH3CN·15H2O...

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

“…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 SMMs have been reported by us. 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.…”

“…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 ). 14,19,27,42–44,53,54 The auxiliary ligands were also usually employed for constructing polynuclear 3d SMMs and 3d-Dy SMMs by us and other research groups. 19,27,42–44,53–56 Moreover, volumes of the auxiliary ligands are smaller than that of Schiff base ligands.…”

“…14,19,27,42–44,53,54 The auxiliary ligands were also usually employed for constructing polynuclear 3d SMMs and 3d-Dy SMMs by us and other research groups. 19,27,42–44,53–56 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.…”

“…5b), which has been reported for other SMM complexes. 44,68 The Cole–Cole plots of 2 can be fitted well by employing the generalized single relaxation process Debye model, 67 with the related parameters listed in Table S10 (ESI†). The ln( τ ) values of 2 continuously increase with increasing T −1 (Fig.…”

“…To our knowledge, employing two kinds of organic ligands can be viewed as an effective method for constructing novel 3d-Dy SMMs. 10,19,42–44 For H 2 L and dpk, they could react with Ni and Dy salts to form the Ni–Dy complexes with novel topologies.…”