opportunities to change the structures in cation and anion, and the length of the side
chain can also be altered to the organic cation to achieve tailored/ functionalized
ionic liquid of special properties.
12.3 Functionalization of Ionic Liquids
The chemo-physical properties of ionic liquids depend on the cation-anion combination and the length of alkyl chain. The functionality of ionic liquids also has a
strong effect on the properties. Thus, the synthesis of functionalized ionic liquids is
generally performed by the integration of functional groups into the cation of ionic
liquid. Till date, mostly, the imidazolium cations are functionalized, and a few
functionalized anions are known. Imidazolium cations can be modified using
functionalized groups such as alkyl halides, hydroxyl groups, carboxylic groups,
thiol groups, alkene groups, diene groups, and so on (Ye and Shreeve 2004; Fei et al.
2005). Using the quaternization method, most of the functional groups directly
added imidazolium moiety and give the desired functionalized ionic liquids. Certain
functionalities require other synthetic routes to be connected to the imidazole
Fig. 12.2 Structure of
common cations and anions
of ionic liquids. (Sun and
Armstrong 2010)
12 Functionalized Ionic Liquids for the Photodegradation of Dyes
395
chain can also be altered to the organic cation to achieve tailored/ functionalized
ionic liquid of special properties.
12.3 Functionalization of Ionic Liquids
The chemo-physical properties of ionic liquids depend on the cation-anion combination and the length of alkyl chain. The functionality of ionic liquids also has a
strong effect on the properties. Thus, the synthesis of functionalized ionic liquids is
generally performed by the integration of functional groups into the cation of ionic
liquid. Till date, mostly, the imidazolium cations are functionalized, and a few
functionalized anions are known. Imidazolium cations can be modified using
functionalized groups such as alkyl halides, hydroxyl groups, carboxylic groups,
thiol groups, alkene groups, diene groups, and so on (Ye and Shreeve 2004; Fei et al.
2005). Using the quaternization method, most of the functional groups directly
added imidazolium moiety and give the desired functionalized ionic liquids. Certain
functionalities require other synthetic routes to be connected to the imidazole
Fig. 12.2 Structure of
common cations and anions
of ionic liquids. (Sun and
Armstrong 2010)
12 Functionalized Ionic Liquids for the Photodegradation of Dyes
395