Effect of anions on architectures of transition metal complexes with 1,4-bis(1,2,4-triazol-1-yl)butane

Abstract

Reaction of transition metal(II) salts with 1,4-bis(1,2,4-triazol-1-yl)butane (btb) formed a series of coordination polymers, [Cu(btb)Cl₂] (1), [Cu(btb)₂]Br₂ (2), [Cu(btb)₂(H₂O)₂](ClO₄)₂ (3), [Cu(btb)_0.5(Ac)₂] (4), [Ni(btb)(H₂O)₃(SO₄)] (5), [Ni(btb)₃](ClO₄)₂ (6), [Ni(btb)₃](NO₃)₂ (7), [Co(btb)(H₂O)₃(SO₄)] (8), [Co(btb)₂(NCS)₂]·H₂O (9), and [Co(btb)_1.5(bdc)(H₂O)] (10) (bdc²⁻ = 1,4-benzenedicarboxylate). These compounds were characterized by single-crystal X-ray diffraction. 1 displays a 1D linear chain and further constructs a 3D supramolecular structure via C–H⋯Cl hydrogen bonds. 2 possesses a 2D helical layer structure. The layers stacked in an AB fashion are linked by C–H⋯Br hydrogen bonds, forming a 3D supramolecular structure. 3 has a threefold interpenetrating diamondoid network with unique helical channels. 4 shows a 1D chain, in which dimeric [Cu₂(Ac)₄] units are bridged by btb ligands. 7 exhibits a threefold interpenetrating α-polonium cubic porous architecture comprising of triple-stranded helices. 10 shows a 3D metal–organic framework constructed from btb and bdc²⁻ligands. Structural results for the complexes 1–10 and reported works show that anions Cl⁻, Br⁻, ClO₄⁻, Ac⁻, SO₄²⁻, NO₃⁻, NCS⁻ and bdc²⁻ play an important role in the assembly of transition metal complexes with 1,4-bis(1,2,4-triazol-1-yl)butane.