Hexacyanometallate as an effective building unit: Soft supramolecular networks to 3D functional porous coordination frameworks

Abstract

Modular synthesis of soft materials, e.g. block copolymers, organic thin films and molecular inclusion compounds, promise precession engineering of specific properties and functions. Amongst them, the class of molecular compounds (also termed as inclusion compounds) is of particular interest because of their widespread applications in the field of magnetism,1 ferroelasticity,2 non-linear optical effects,3 chemical storage4 and catalysis.5 Moreover, extended networks sustained solely by non-covalent interactions exhibit a greater degree of flexibility resulting in selectivity in terms of guest accommodation.6 The flexible structure could be compared to a human hand as it is very easy to recognize forms and shapes which is also having multifunctional characters. Crystalline solids have intrinsic advantages where crystallinity allows an efficient collection of guests because of the large number of same repeating porous units, whereas flexibility produces a highly selective capture of guests. Designing new class of functional host materials based on the art of host–guest systems, one could easily extrapolate the attributes of both crystallinity and flexibility in such type of materials. Such modular nature of a host framework would provide not only rigid properties, but also enzyme-like soft specificity, producing intelligent host materials that are responsive to guests under the appropriate conditions.