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.