Design, synthesis, and structures of two-dimensional copper(I) coordination polymers by variation of co-ligands in a facile one-pot reaction

Two new coordination polymers [Cu2(μ3-I)2(μ-bbd)]n (1) and [Cu2(μ3-Br)2(μ-bbd)]n (2) based on ladders with Cu2X2 (X = I, Br) structural units were prepared at room temperature by the reactions of the respective copper(I) halides with a ditopic flexible linker ligand 1,4-bis(3,5-dimethypyrazol-1-yl)butane (bbd) in DMF as solvent. The complexes have been characterised by elemental analyses, IR spectroscopy, thermal analysis, and single-crystal X-ray diffraction. In the crystal structures of 1 and 2, parallel [Cu2X2]n ladders or staircases are cross-linked into two-dimensional sheets by μ-bbd ligands with a fully extended conformation. The ladders and sheets have the same structural topology and almost identical geometry in the two structures, but pack in different crystal systems and space groups, the structures being related to each other as polytypes.

Reaction of CuI or CuBr and the ligand bbd having two pyrazole rings linked by a (CH2)4 chain gives complexes in which parallel [Cu2X2]n staircase polymers are linked into polymeric sheets by μ-bbd ligands with a fully extended conformation. These ladders and sheets have essentially the same geometry, but pack differently in the two polytypic structures.Figure optionsDownload as PowerPoint slide