title: Exceptional self-penetrating networks containing unprecedented quintuple-stranded molecular braid, 9-fold meso helices, and 17-fold interwoven helices.
abstract: Self-assembly of long V-shaped ligands and d10 metal salts in the presence of a linear bidentate ligand affords two unprecedented self-penetrating coordination networks {[Zn4(bptc)2(bpy)4].(C5H3N).4H2O}n (1) and {[Cd2(sdba)2(bpy)(H2O)2].2H2O}n (2) (bptc = 3,3',4,4'-benzophenonetetracarboxylate, sdba = 4,4'-sulfonyldibenzoate, bpy = 4,4'-bipyridine). Their structures were determined by single-crystal X-ray diffraction analyses and further characterized by elemental analyses, IR spectra, X-ray powder diffraction, and TG analyses. 1 adopts a novel 3D framework containing three types of molecular braids, among which the quintuple-stranded molecular braid represents the highest-stranded molecular braid presently known for entangled systems. 2 is an uncommon self-penetrating 2D network containing pseudo-Borromean links and double-stranded helices. More interestingly, when the strong hydrogen bonds between layers are taken into account, the resulting net of 2 becomes an eight-connected 3D self-penetrating network with an unprecedented (421.67) topology, which represents the highest connected topology presently known in self-penetrating systems. Furthermore, the photoluminescent properties of 1 and 2 were studied.
authors: Key Laboratory of Polyoxometalate Science of Ministry of Education, Institute of Polyoxometalate Chemistry, Department of Chemistry, Northeast Normal University, Changchun 130024, People's Republic of China.
authors: Dong-Rong
authors: DR
authors: Xiao
authors: Yang-Guang
authors: YG
authors: Li
authors: En-Bo
authors: EB
authors: Wang
authors: Lin-Lin
authors: LL
authors: Fan
authors: Hai-Yan
authors: HY
authors: An
authors: Zhong-Min
authors: ZM
authors: Su
authors: Lin
authors: L
authors: Xu