Hydrothermal Synthesis, Crystal Structure and Properties of a Novel 3D Metal-Organic Cd(II) Coordination Polymer Based on Helical Units

Institute of Environmental and Municipal Engineering, North China University of Water Conservancy and Electric Power, Zhengzhou 450011, P. R. China

A metal-organic framework based on 4-methylphthalic acid (H₂L) and 4,4′-bipyridine (bpy), namely {[Cd(L)(bpy)_1.5]·2(H₂O)}_n (1), has been synthesized hydrothermally and characterized by IR spectroscopy, elemental analysis, thermogravimetry, and single-crystal X-ray crystallography. Complex 1 exhibits a 3D coordination network based on layers. Each layer consists of left- or right-handed {Cd-L-Cd-bpy-Cd-L-Cd-bpy}_n double helices. Water molecules are also incorporated in the network. Compound 1 shows fluorescence at ca. 360 nm upon excitation at 304 nm.