Assembly of 1,2,3,4-Benzenetetracarboxylic Acid and Zinc(II) Metal Centers to a Chiral 3D Metal-organic Framework: Syntheses, Structure and Properties

A new three-dimensional metal-organic framework {[Zn(mpda)(0.5)(bix)]center dot(H2O)(1.5)}(n) (1) (H(4)mpda = 1,2,3,4-benzenetetracarboxylic acid, m-bix = 1,3-bis(imidazol-1-ylmethyl)-benzene) has been synthesized and characterized by single-crystal X-ray diffraction and IR spectra. In 1, homochiral helical chains are formed in the Zn-mpda layer through spontaneous resolution by mpda(4-). Such layers are further connected through the second m-bix ligand to form a 3D chiral metal-organic framework. The individual (4,4)-connected net in 1 can be specified by the Schlafli symbol (6(6))(2)(6(4).8(2)). Bulk material of 1 has good second-harmonic generation (SHG) activity, approximately 0.4 times that of urea. In addition, a thermogravimetric analysis was carried out, and the photoluminescent behavior of the complex was also investigated.