Iminiumsions

Iminiumsions is a coined term used in speculative chemistry to describe proposed extended networks built from iminium centers linked into two- or three-dimensional frameworks. An iminium node arises from a positively charged nitrogen-containing center, typically described by a resonance form such as R2C=NR+. In this concept, such nodes serve as junctions that connect with covalent or noncovalent bridges to form delocalized, ion-rich structures. The term implies a hybrid between ionic character and extended conjugation, potentially yielding unique electronic and catalytic properties.

Structural motifs in iminiumsions are envisaged as arrays where iminium nodes are connected by polytopic linkers, including aryl, vinyl, or heteroatom bridges. Frameworks could be 2D sheets or 3D networks, with counterions balancing overall charge. The linking chemistry may involve condensation-type iminium formation, reversible iminium–amine exchanges, or supramolecular interactions that stabilize the assembly.

Synthesis routes in the concept range from in situ generation of iminium bonds via condensation of carbonyl compounds with amines to the stabilization of these linkages through controlled oxidation or reduction. Alternatively, preformed iminium nodes can be assembled with multivalent linkers under supramolecular guidance, aided by hydrogen-bonding, π–π stacking, or coordination chemistry.

Properties often predicted for iminiumsions include tunable electronic structure, redox activity, and ionic conductivity, with potential stability in polar media. Reported interest centers on possible applications in catalysis, sensing, energy storage, and ion-transport materials. As a theoretical construct, iminiumsions remain at the speculative stage, with limited experimental realization to date. See also iminium, covalent organic frameworks, and poly(iminium) materials.