A New Metal-organic Framework Constructed from Flexible Polycarboxylate Acid and Rigid Imidazole-based Ligands

A new complex, [Ni3(L)2(BTA)2]·2H2O (1, L=1,4-di(1H-imidazol-4-yl)benzene, H3BTA=benzene-1,3,5-triacetic acid), has been hydrothermally prepared and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis, TG and PXRD. The complex crystallizes in monoclinic, space group P1 with a=9.0303(12), b=10.0796(13), c=12.7966(17) , α=99.268(2), β=94.490(2), γ=103.722(3)o, V=1108.5(3) 3 , Z=2, C48H38N8O14Ni3 , Mr=1126.99, Dc=1.688 g/cm3 , μ=1.344 mm-1 , S=1.001, F(000)=578, the final R=0.0389 and wR=0.0895 for 3083 observed reflections (I > 2σ(I)). In the title complex, the flexible BTA3- ligands utilize oxygen atoms of carboxylate groups to coordinate with Ni(II) ions to form two-dimensional double-layer networks which are further pillared into a three-dimension framework via the rigid ditopic ligand L. Topological analysis revealed that complex 1 is a typical (3,8)-connected tfz-d 3D network based on the trinuclear [Ni3(CO2)6N4] subunits.