A 2D Copper(Ⅱ) Complex with Half Paddlewheel-like Building Block Controlled by 1,2,4,5-Benzenetetracarboxylic Acid: Synthesis,Crystal Structure and Luminescence Property

Self-assembly reaction of 1,2,4,5-benzenetetracarboxylic acid(H_4 btc) with CuCl_2 in mixed N,N-dimethylformamide(DMF), methanol and aqueous solution at room temperature generated a 2D complex, [Cu(btc)_(0.5)(DMF)(H_2 O)]_n(1) which was further characterized by X-ray diffraction, IR spectrum, elemental analysis and TG-DTA experiments. The structure determination reveals that the fundamental unit of complex 1 contains one Cu(Ⅱ) ion, half a btc~(4–), one DMF molecule and one water molecule, forming a half paddlewheel-like building block [Cu_2(btc)(DMF)_2(H_2 O)_2] which is different from those previous Cu-btc(Ⅱ) polymers obtained either in water or other media without water. It crystallizes in monoclinic system, space group C2/c with a = 22.8209(14), b = 9.2244(6), c = 10.8876(7) ?, b = 117.5210(10)o, V = 2032.6(2) ?~3, Z = 2, C_8 H_(10) CuNO_6, M_r = 279.71, D_c = 1.828 g/cm~3, μ = 2.162 mm-1, F(000) = 1136, the final R = 0.0225 and wR = 0.0652 with I 2s(I). Furthermore, the thermal stability of complex 1 is observed to be dependent on the polymeric structure nature. And the luminescent measurements show that complex 1 produces strong emission at room temperature.