1D tubular chains and 3D polycatenane frameworks constructed with Cu2X2 dimers (X = Br-, I-, CN-) and flexible dipyridyl spacers

Five new coordination polymers based on copper( I) halides or pseudohalide, [Cu2Br2(bpe)(2)] ( 1), [Cu-2(CN)(2)(bpe)] ( 2), [Cu2Br2(bpp)(2)] ( 3), [Cu2I2(bpp)(2)] center dot(toluene) ( 4), and [Cu2I2(bpp)(2)] center dot (naphthalene) (5) (bpe = 1,2-bis(4-pyridyl) ethane, bpp) 1,3-bis(4-pyridyl) propane), have been synthesized by solvothermal methods and characterized by X-ray crystallography. All structures can be deconstructed into rhomboid Cu2X2 (X = Br, I, CN) dimers and flexible bridged dipyridyl ligands. In 1, two sets of (4,4) layers adopt the "diagonal- diagonal" 4-fold interpenetration mode, giving high catenation and generating a novel 2D --> 3D interpenetrating framework. 2 is a 3D (3,6)-connected rutile-like net of 2-fold interpenetration. Each 3D rutile-like net consists of 2D flat [Cu-2(mu(3)-CN)(mu-CN)] layers and bpe pillars. 3 is a 2D polycatenane formed by interlocking of 1D double-stranded tubular chains. 1D double-stranded tubular chains are also present in 4 and 5, similar to that found in 3; however, the presence of toluene or naphthalene guests prevents the 1D double-stranded tubular chains from interpenetration. The photoluminescent properties of 1 and 3 in the solid state have been studied.