Supramolecular 2D and 3D frameworks based on 1-amino-2-phenylethane-1,1-diphosphonic acid

The 1-amino-2-phenylethane-1,1-diphosphonic acid (APhEDPH(4)) is easily assembled to form two-dimensional (2D) supramolecular layer. It crystallizes from water solution to form hydrated compound APhEDPH(4)center dot 3H(2)O (1). By introducing a base bridging ligand 4,4'-bipyridyl (4,4'-bipy), another supramolecular compound (APhEDPH(3))(2)center dot(4,4'-bipyH(2)) (2) is obtained. Both of them were characterized by X-ray diffraction (XRD), elemental analysis (EA), infrared spectrometry (IR), thermogravimetric analysis (TGA) and single crystal X-ray diffraction. In compound 1, APhEDPH(4) molecules form 2D supramolecular layers and extend to 2D sandwich type supramolecular architecture with the existence of water molecules. Whereas, compound 2 contains 2D supramolecular layers constructed by APhEDPH(3)(-) anions, and shows a three-dimensional (3D) tessellate-type supramolecular structure via the bridging effect of 4,4' - bipyH(2)(2+). Compound 2 shows intense blue photoluminescence with when excited by ultraviolet ray. The effect of bridged ligand on the dimensions of the final product is also discussed. (C) 2008 Elsevier B.V. All rights reserved.