An odd-numbered heptameric water cluster containing a puckered pentamer self-assembled in a Ag(I) polymeric solid

Abstract

A mixed-ligand Ag(I) coordination polymer {[Ag 2 (bpe) 2 (H 2 O) 2 ](chd)·5H 2 O} n ( 1 ) (bpe = 4,4′-bipyridylethylene, H 2 chd = 1,4-cyclohexanedicarboxylic acid), has been synthesized and structurally characterized. Complex 1 exhibits a three-dimensional (3-D) supramolecular sandwich architecture that is composed of cationic chains of Ag(I) ions and bpe ligands, alternating with anionic sheets in which uncoordinated chd 2 − anions and water molecules form a 2-D hydrogen-bonded network. An odd-numbered (H 2 O) 7 cluster is trapped inside the water-chd aggregation. The discrete water heptamer consists of a puckered pentameric core and two pendent water molecules and structurally shows similarity to the simple hydrocarbon (1,1)-dimethylcyclopentane. A discrete and odd-numbered (H 2 O) 7 cluster which consists of a puckered water pentamer and two dangling water molecules and shows a similar to the simple hydrocarbon (1,1)-dimethylcyclopentane, is unambiguously trapped in a Ag(I) mixed-ligand coordination polymer {[Ag 2 (bpe) 2 (H 2 O) 2 ](chd)·5H 2 O} n ( 1 ) (bpe = 4,4′-bipyridylethylene, H 2 chd = 1,4-cyclohexanedicarboxylic acid). ► One novel Ag(I) complex was synthesized and characterized. ► The complex contains a 2D hydrogen-bonded water-chd aggregation based on odd-numbered (H 2 O) 7 clusters. ► The (H 2 O) 7 cluster consists of a puckered water pentamer and two dangling water molecules. ► The (H 2 O) 7 cluster shows similarity to the simple hydrocarbon (1,1)-dimethylcyclopentane.