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Year: 2009 | Volume: 62 | Issue: 23 | Page No.: 3782 - 3794
Xiao-Li Yang, Shi-Bin Ren, Jun Zhang, Yi-Zhi Li, Hong-Bin Du and Xiao-Zeng You
Abstract
Using 4-methylbenzenethiolates of Zn or Cd as precursors and 4,4’-bipyridine (4,4’-bpy) as bridges, we have synthesized three new Zn(II)/Cd(II) coordination polymers, {[Cd(4,4’-bpy)2(NCS)2] · 2(SC6H4CH3-4)2}n (1), {[Zn(4,4’-bpy)(SC6H4CH3-4)2] · DMF}n (2) and {[Zn(4,4’-bpy)(SC6H4CH3-4)2] · H2O · 0.5CH3OH}n (3). Compound 1 is a 2-D sheet-like square polymer in which four 4,4’-bpy ligands and two isothiocyanate ligands complete the octahedral Cd(II) coordination sphere. Compounds 2 and 3 have similar coordination around Zn(II), but have different polymer structures. In 2, Zn(II) centers are linked via a bidentate 4,4’-bipyridine to form 1-D twisted arched chains, which is a new structural type for Zn(II). Compound 3 has 1-D zigzag chains. The 2-D sheets in 1 and 1-D chains in 2 and 3 are assembled via intermolecular C-H … π and C-H … S interactions into 3-D supramolecular networks. C-H …S interactions are a vital factor in constructing the sulfur-containing coordination polymers. Different coordination modes and packing schemes in 1-3 show that the guest molecule has a critical influence on formation of polymers.