Cu(II) coordination polymers based on 1,3,5-tris(triazol-1-ylmethyl)-2,4,6-trimethylbenzene: synthesis, structure, and biological properties

Two new Cu(II)-based coordination polymers, [Cu(TTTMB)(Hbtrc2−)]n (1) and {[Cu(TTTMB)2(H2O)2](NO3)2(H2O)4}n (2), were synthesized under hydrothermal conditions (TTTMB = 1,3,5-tris(triazol-1-ylmethyl)-2,4,6-trimethylbenzene; H3btrc = 1,3,5-trimesic acid). The structures of these polymers were established by elemental analysis, IR, and single-crystal X-ray diffraction analysis. Polymer 1 displays a three-dimensional (3-D) structure with the Schläfli symbol (4·62)(4·67·82) and crystallizes in the monoclinic space group P2(1)/n. Each Cu(II) in 1 is five-coordinate in a slightly distorted rectangular pyramid geometry. Polymer 2 has a 2-D network structure with (4,4) topology and each Cu(II) ion has a slightly distorted octahedral coordination geometry. The antidiabetic activity against α-amylase and antioxidant activity against DPPH of the two Cu(II)-based complexes were evaluated in vitro. Polymers 1 (IC50 = 1.43 mg/mL) and 2 (IC50 = 2.45 mg/mL) exhibited more effective inhibition on α-amylase than the standard drug acarbose (IC50 = 2.94 mg/mL). The results of the antioxidant studies revealed that 2 demonstrated a potent scavenging effect on DPPH with IC50 values of 2.59 mg/mL, slightly lower than that of vitamin E (2.67 mg/mL).