Synthesis, structure, fluorescent and magnetic properties of a series of coordination polymers based on a long and flexible bis-triazole ligand

Using the long and flexible bis(4-(4H-1,2,4-triazol-4-yl)phenyl)methane (BTPM) as a ligand, six novel coordination polymers have been synthesized under hydrothermal conditions. {[Zn(BTPM)(HCOO)](NO ₃)·2.25H ₂O} _n (1) and {[Cd(BTPM)(HCOO)](NO ₃) ·H ₂O} _n (2) exhibit 2D bi-wave layers with one dimensional microchannels of 9 × 9 Å ², which can form 3D supramolecular structures by intermolecular hydrogen bonds. Both {[Zn ₂(BTPM) ₃(H ₂O) ₄](NO ₃) ₄·H ₂O} _n (3) and {[Cd ₂(BTPM) ₃(H ₂O) ₄](NO ₃) ₄·3. 5H ₂O} _n (4) are composed of multiple pairs of interpenetrating (4,4) sheets. {[Cu ₈(μ ₄-O) (μ ₂-H ₂O) ₂(BTPM) ₁₂](ClO ₄) ₁₄·4H ₂O} _n (5) and {[Co ₃(BTPM) ₃(H ₂O) ₆](NO ₃) ₆·7H ₂O} _n (6) are 3D interpenetrating frameworks. In complex 5, a rare square planar tetra-coordinate oxygen (ptO) and two different tetranuclear copper(ii) clusters, [Cu ₄(μ ₂-H ₂O) ₂N ₂₀] and [Cu ₄(μ ₄-O)N ₂₀], have been observed. Complex 6 shows a 6-connected topology based on linear trinuclear clusters. The fluorescent properties of 1-4, as well as the magnetic properties of 5 and 6 are studied.