Photoluminescent Honeycomb Structures from Polyoxometalates and an Imidazolium-Based Ionic Liquid Bearing a π-Conjugated Moiety and a Branched Aliphatic Chain

Graphical Honey trap : Highly-ordered, photoluminescent honeycomb structures with rich electrochemical properties have been fabricated by complexing {Mo 72 Fe 30 } and a room-temperature ionic liquid which bears naphthyl unit and a long, branched aliphatic chain. Honeycomb-structured films represent an intriguing class of two-dimensional porous materials. Specifically, polyoxometalate (POM) macroanions can be introduced into these films by complexing with oppositely charged, double-tailed surfactants. Here highly-ordered honeycomb structures are reported that can be constructed by the complexes between POMs and a room temperature ionic liquid ( IL1 ) having an imidazolium moiety in the middle and a naphthyl unit and a branched aliphatic chain at the ends. The complexes can be produced through phase transfer between an aqueous solution of POMs (typically {Mo 72 Fe 30 }) and a CS 2 (or chloroform) solution of IL1 . Based on the intrinsic properties of {Mo 72 Fe 30 } and the functional groups of the IL1 , the honeycomb structures show multiple functions with bright photoluminescence and rich electrochemical properties. This work shows that by simply engineering the organic ligands involved in the POM-based inorganic–organic complexes, supramolecular structures with improved properties and wide applications can be obtained.