A (3, 4, 14)-connected framework with various distorted triangular magnetic lattices exhibiting field-induced metamagnetism, spin competition and spin reorientation

Abstract

A (3, 4, 14)-connected framework with complicated distorted triangular magnetic lattices, {[Co(7)(H(2)O)(4)(trz)(8)(sip)(2)]·3H(2)O}(n) (trz = 1,2,4-triazolate, sip = 5-sulfoisophthalate), exhibits continuous field-induced metamagnetic transition from an antiferromagnetic ordering to a ferrimagnetic state at 15 kOe, spin competition at 26 kOe and spin reorientation at 50 kOe, respectively.

Three 3-amino-1,2,4-triazole-based cobalt(II) complexes incorporating with different carboxylate coligands: synthesis, crystal structures, and magnetic behavior

“…As shown in figure 1(a), the sole Co II ion in 1 is hexa-coordinated by four equatorial carboxylate O donors from three separate nip 2− coligands and two axial triazolyl N atoms from two individual Hatz molecules, adopting distorted octahedral coordination geometry. The Co-O distances are between 2.0272(15) and 2.2436(15) Å and the Co-N separations fall in the normal range of 2.1458(17) to 2.1528(17) Å (see table 2), which are comparable with those Co II -based complexes with mixed carboxylate and tri-/tetrazolyl ligands [13,14,22]. Notably, the Co-O distances for the chelating carboxylate are obviously longer (ca.…”

“…The Co II ⋅⋅⋅Co II separation in 3 is slightly shorter than that of 2 (3.8749(5) Å), but somewhat longer than those observed in [Co 2 (datrz) 2 (nb) 2 ] n (3.7017(6) and 3.5679(6) Å) [13] and {[Co 7 (H 2 O) 4 (trz) 8 (sip) 2 ]⋅3H 2 O} n (3.6936(4) and 3.2708(3) Å, sip 3− = 5-sulfoisophthalate) [14] bridged by the datrz -and 1,2,4-triazolate (trz -) ligands. The linear trinuclear entities are further connected with N-H⋅⋅⋅O hydrogen bonding interaction between the exocyclic amino/endocyclic imino moiety of Hatz ligand and the carboxylate group of btc 3− anion (table 5), leading to a 3D non-covalent network ( figure 3(b)).…”

“…For example, a series of Cu II 4 cluster-based three-dimensional (3-D) coordination polymers with interesting framework connectivity have recently been obtained by varying the polycarboxylate-containing coligands [10,18], which, resulting from the cooperate interactions of the multiple heterobridges, have displayed strong antiferromagnetic interactions with the coupling constant up to 206 cm −1 [10,11]. In contrast to the isotropic magnetic systems, the magnetic samples containing anisotropic Co II ion possess interesting pillaredlayered architecture or mixed corner-and/or edge-sharing triangular magnetic lattices, and display field-induced multiple-step magnetic transitions [13,14]. Obviously, the single-ion anisotropy, the spin-orbit coupling of the spin carriers, the coordination preference of the mixed magnetic mediators, and the diverse magnetic lattices generated by the paramagnetic ion and triazolyl group were found to significantly govern the magnetic behaviors.…”

“…Collecting paramagnetic transition metal ions (Mn 2+ , Fe 2+ , Co 2+ , Ni 2+ , Cu 2+ , and so on) with appropriate bridging ligands through a bottom-up approach has becoming one of general strategies for the preparation of a magnetic sample [3]. Acting as a large family of versatile ligands to coordinate with spin carriers in selective bi-, tri-and tetradentate bridging modes, five-membered N-heterocyclic azoles with two or more N donors separated by ring carbon atoms (imidazole, triazole, and tetrazole) and their abundant derivatives have been extensively employed as short magnetic mediators to construct novel magnetic metal complexes [4][5][6][7][8][9][10][11][12][13][14][15][16][17]. More interestingly, the structural and magnetic diversities of these polyazolyl-based magnetic entities can be significantly triggered by introducing different spin carriers and secondary mediators [3,6,10,11].…”

Structures and magnetic properties of mixed triazolyl-aromatic polycarboxylate-based metal complexes

“…卢灿忠课题组 [16] 于 2007 年报道了 含 H 4 btec 的三唑-金属配合物[Zn 7 (trz)(btec) 2 (H 2 O) 6 ] n • 8nH 2 O, 在该配合物中, 由于 btec 4 配体中相邻两个 羧基与三唑的协同配位作用, 该配合物中形成了具有 七核子单元的一维宽带(图 6(d)). Dalai 课题组 [40] 与乐 善堂等 [41] [18] 将 1,2,4-苯三酸(1,2,4-H 3 btc) 与 Htrz 混配, 合成了具有金属-三唑带状结构的锌(II)配 图 6 三唑-金属一维链/带状子结构 [16,18,30,34,36,40,41] 合物[Zn 5 (trz) 4 (1,2,4-btc…”