Table 1.
Comparison of ionic liquids with organic solvents [49].
| Property | Organic Solvents | Ionic Liquids | |||
|---|---|---|---|---|---|
| Number of solvents | >1,000 | >1,000,000 | |||
| Applicability | Single function | Multifunction | |||
| Catalytic ability | Rare | Common and tunable | |||
| Chirality | Rare | Common and tunable | |||
| Vapour pressure | Obeys the Clausius-Clapeyron Equation | Negligible under normal conditions | |||
| Flammability | Usually flammable | Usually nonflammable | |||
| Solvation | Weakly solvating | Strongly solvating | |||
| Tunability | Limited range of solvents available | Unlimited range means 'designer solvents' | |||
| Polarity | Conventional polarity concepts apply | Polarity concept questionable | |||
| Cost | Normally inexpensive | 2 to 100 times the cost of organic solvents | |||
| Recyclability | Green imperative | Economic imperative | |||
| Viscosity/cP | 0.2-100 | 22-40,000 | |||
| Density/g cm-3 | 0.6-1.7 | 0.8-3.3 | |||
| Refractive index | 1.3-1.6 | 1.5-2.2 |