Self-assembly of two fluorescent supramolecular frameworks constructed from unsymmetrical benzene tricarboxylate and bipyridine

Two new supramolecular compounds, [Ag(4,4'-bipy)](n) [Ag(HBTC)(n) (1) and [Cu(H(2)BTC)2,2-bipy)] (2) (HBTC/H(2)BTC = 1,2,4-benzenetricarboxylate, 4,4'-bipy/2,2'-bipy = 4,4'/2,2'-bipyridine), have been synthesized and characterized by elemental analyses, IR spectra, ultraviolet-visible diffuse reflection integral spectra (UV-Vis DRIS), fluorescent spectra, thermogravimetric analysis and single crystal X-ray diffraction analysis. It is noteworthy that there were two kinds of one-dimensional stairs-chain including cationic [Ag(4,4'-bipy)(n) chain and anionic [Ag(HBTC)(n) chain in 1. Furthermore, a two-dimensional double layer supramolecular framework was constructed through coordination bonds, hydrogen bonds, pi-pi stacking interactions and Ag center dot center dot center dot O weak coordinative interactions. The one-dimensional supramolecular chain of 2 was built from combining mononuclear [Cu(H(2)BTC)(2,2'-bipy)] by inter- and intramolecular hydrogen bonding interactions. Additionally, the two complexes exhibit intense blue or olivine luminescence at room temperature. (c) 2007 Elsevier B.V. All rights reserved.