Multiple anion···π interactions with a soft selenium atom: Accommodation of NCSe− anions inside hydrophobic pockets of adamantane/1,2,4-triazole coordination framework

A new framework coordination polymer {[Cd3(tr2ad)6](NCSe)6·12H2O}n [tr2ad-4,4′-(adamantane-1,3-diyl)bis(1,2,4-triazole)] exhibits 3D primitive cubic topology adopted by trinuclear [Cd3(tr)12] net nodes and tridentate tr2ad links. The structure reveals unprecedented multiple anion ···π interactions employing the soft Se site of the ambifunctional NCSe− anion and three triazole groups pre-arranged on a tricadmium matrix. The framework generates hydrophobic pockets serving for hosting the uncoordinated anions by a concerted action of Se···π and CH···Se interactions.

Graphical AbstractA new bis(1,2,4-triazolyl)adamantane framework coordination polymer reveals unprecedented multiple anion interactions employing the soft Se site of the ambifunctional NCSe-anion.Figure optionsDownload as PowerPoint slideResearch Highlights
► Se···π interactions are relevant for the host-guest chemistry of selenocyanate.
► Cd/1,2,4-triazole moiety provides hydrophobic pockets for hosting the anions.
► Adamantane bitriazole supports trinuclear nodes of the 3D metal-organic framework.