Two 3D Triazolate−Tricarboxylate-Bridged Cu^II/I Frameworks by One-Pot Hydrothermal Synthesis Exhibiting Spin-Canted Antiferromagnetism and Strong Antiferromagnetic Couplings

Abstract

Two 3D coordination polymers with the same components but different structures, [Cu(II)(2)Cu(I)(trz)(3)(Hbtc)](n) (1) and [Cu(4)(Htrz)(2)(mu(3)-OH)(2)(btc)(2)](n) (2), were obtained together by a one-pot hydrothermal reaction of Cu(OAc)(2).H(2)O, 1,2,4-triazole (Htrz), and 1,3,5-benzenetricarboxylic acid (H(3)btc). Complex 1 is a mixed-valence Cu(I/II) honeycomb built from wavy Cu(II)-trz-carboxylate layers and Cu(I) nodes with doubly deprotonated Hbtc(2-) ligands covalently filled in the channels. In contrast, 2 is a tetranuclear [Cu(4)(Htrz)(2)(mu(3)-OH)(2)](6+) cluster-based framework extended by a fully deprotonated btc(3-) ligand, displaying a 3,6-connected topological network. More interestingly, spin-canted antiferromagnetism and overall strong antiferromagnetic couplings up to -147.1 cm(-1) are respectively observed for 1 and 2, which are significantly due to the antisymmetric magnetic exchange in the wavy Cu(II)-trz-carboxylate sublayer of 1 and the cooperative 4-fold heterobridges within the tetranuclear cluster of 2.

A novel Cu5II cluster-based 3D magnetic framework with an overall S= 1/2 spin ground state

“…Secondly, polycarboxylate-based conjugated aromatic ligand with conformation-dependent three-atom carboxylate bridges and the relatively rigid skeleton prefers to mediate efficient superexchange interactions between spin-carriers and to endow the robustness of the connectivity, which can essentially contribute to long-range bulk magnetic properties and high thermal stability of the resulting frameworks. Finally, the synthesis of MCCPs is usually involved in the controllable hydrolysis of metal salts with the aid of carboxylate ligand under the hydrothermal reactions, in which the co-coordination of the bi-/ tridentate hydroxyl group and/or water molecule can help to induce the aggregation of more metal ions and to consolidate the local cluster motif [5,8]. Up to date, a series of carboxylate-aggregated polynuclear MCCPs including tetra- [5,9], hexa-[10], hepta-[11] and even nonanuclear aggregates [12], have been successively obtained and exhibited interesting magnetic properties, such as spin glassy, metamagnetism, single molecule magnets, etc.…”

“…Finally, the synthesis of MCCPs is usually involved in the controllable hydrolysis of metal salts with the aid of carboxylate ligand under the hydrothermal reactions, in which the co-coordination of the bi-/ tridentate hydroxyl group and/or water molecule can help to induce the aggregation of more metal ions and to consolidate the local cluster motif [5,8]. Up to date, a series of carboxylate-aggregated polynuclear MCCPs including tetra- [5,9], hexa-[10], hepta-[11] and even nonanuclear aggregates [12], have been successively obtained and exhibited interesting magnetic properties, such as spin glassy, metamagnetism, single molecule magnets, etc. As our continuing interest in the preparations and properties of MCCPs [5,12,13], herein, a novel Cu 5 II cluster-based 3D coordination framework extended by fully deprotonated 5-nitroisophthalate (nip 2− ) ligand, {[Cu 5 (μ 3 -OH) 2…”

“…Among diverse core-formation ligands with typically chelating groups such as polyazole [4,5], azide [6], carboxylate group [7] and so on, conjugated aromatic polycarboxylate ligand can be regarded as one of good candidates for MCCPs. Firstly, short carboxylate group can tightly aggregate two or more metal ions into a small molecular entity by its various coordination modes [7].…”

Exploring the copper(II)–aminotriazole complex-binding sites of human serum albumin

“…Specifically, the interest in these ligands often derives from their versatility to bridge metal centers in different motifs [10][11][12]. As an area to explore, the use of the aminotriazole systems to obtain metal complexes could interact with HSA and produce HSA cleavage.…”

A novel 3D homochiral helical coordination polymer based on a flexible tripodal ligand

“…On the other hand, 1,2,4-triazole groups can freely twist around the -CH 2 -groups, so tttmb can adopt two different coordination conformations (cis,trans, trans-and cis,cis,cis-conformations) to prepare coordination polymers with charming structures. In addition, the application of mixed ligands is presently an effective approach for constructing compounds [22][23][24]. Thus, the employment of flexible tripodal N-donor ligands and aromatic polycarboxylate species may have great potential for the construction of a variety of fascinating structures.…”