Copper(II) coordination polymers constructed from aromatic polycarboxylate and flexible triazole ligands with different spacer lengths: syntheses, structures, and properties

{[Cu-2(btm)(2)(Hbtc)(H(2)btc)(2)(H2O)]center dot 9.5H(2)O}(n) (1), [Cu(bte)(H(2)btc)(2)](n) (2) {[Cu(btp)(H(2)btc)(2)]center dot 0.25H(2)O}(n) (3) (btm=bis(1,2,4-triazol-1-yl)methane, bte=bis(1,2,4-triazol-1-yl)ethane, btp=bis(1,2,4-triazol-1-yl)propane, H(3)btc=benzene-1, 3, 5-tricarboxylic acid) have been synthesized and structurally characterized. 1 features a 1-D double chain, which is interconnected by classical hydrogen-bonding (O-H center dot center dot center dot O) and pi-pi interactions to lead to a 3-D supramolecular architecture. 2 and 3 are both 1-D single chains, which are interconnected by pi-pi interactions to 2-D layer architectures. Elemental analysis, XRD, IR, TG and EPR spectra have been carried out and discussed.