The gelling ability of some geminal imidazolium salts was investigated
both in organic solvents and in water solution. Organic
salts differing either in the cation or anion structure
were taken into account. In particular, the effects on the gelphase
formation of isomeric substitution on the cation or
anion as well as of the use of mono- or dianions were evaluated.
As far as the cation structure is concerned, isomeric cations,
such as 3,3’-di-n-octyl-1,1’-(1,4-phenylenedimethylene)diimidazolium
and 3,3’-di-n-octyl-1,1’-(1,3-phenylenedimethylene)
diimidazolium, were used. On the other hand, in addition
to the bromide anion, isomeric dianions, such as the 1,5- and
2,6-naphthalenedisulfonate anions, were also examined. After
preliminary gelation tests, different factors affecting the obtained
gel phases, such as the nature of the solvent, organogelator
concentrations, and action of external stimuli, were analyzed.
The gel-phase formation was also studied as a function
of time, by using resonance light scattering measurements. Gel
morphologies were analyzed by scanning electron microscopy.
To further support the understanding of the different behavior
shown by the isomeric cations, some representative ion pairs
were analyzed by DFT-based investigations. The collected data
underline the significant role played by isomeric substitution
of both cation and anion structures in determining the gelling
capability of the investigated salts, as well as the properties of
the gel phases. Finally, DFT investigations were helpful in the
identification of the structural features affecting the self-assembly