The document discusses ionic liquids, which are organic salts that are liquid below 100°C. They can be used as solvents in various applications such as electrochemical devices and chemical synthesis. The document outlines the history of ionic liquids and different types including protic and aprotic ionic liquids. It also discusses the use of ionic liquids in applications like electrolytes and catalysis. Furthermore, it covers switchable ionic liquids that can change polarity and discusses their synthesis and potential to reduce solvent use. The document emphasizes the need to consider the full life cycle and disposal of ionic liquids to determine their sustainability.

1. Seminar Project 2
Submitted by Rakhi Shyamlal Vishwakarma
16GRT209
Mtech Green Technology

2.  Organic salts having melting points below 100°C.
 Used by modification of cation, anion, or both.
 Mainly used in electrochemical devices, chemical synthesis and heat transfer fluids
 Non-volatile and thermally stable

3.  19th century First ionic liquid: Red oil: Friedal-craft reaction
 The structure of red oil as a salt having a cation NMR spectroscopy
 Prof. Jerry Atwood from university of Missouri indicated this early ionic liquid
 20th century Aluminium nitrate
 1960s Prof. John Yoke Oregon State University mixture of copper (I) chloride and alkyl
aluminium chloride

4. Protic ionic liquid Aprotic liquid Inorganic ionic liquids Solvate (Chelate) ionic
liquid
Proton transfer from a
brØnsted acid to a brØnsted
base
Liquids involving cations
are organic molecular ions
(contains no acidic protons)
Present in both protic and
aprotic ionic liquid
Unexplored class of ionic
liquids
High fluidity and
conductivity
Low melting points
Low fluidity and
conductivity
High melting points
Advantage of similar
packing problem that result
in low melting ILs of the
organic cation type
Multivalent cation salts that
does not satisfy the criteria
of low melting points
Cheaper and easy to
synthesis
Less ability to react quickly
with fresh metallic surface
Aprotic example
Lithium chlorate
Melting point 115°C
Molten salt hydrates like
calcium nitrate
tetrahydrates, which forms
ideal mixtures with alkali
metals
Alkylammonium nitrate
Ethanolammonium nitrate
Hexafluorophosphate
Tetrafluoroborate
Protic example
Hydrazinium nitrate
Melting point 80°C

5. Alkylammonium- Dialkylamidazolium- Phosphonium- N-alkylpyridinium
Electrolytes
Electrochemical devices
Develops reactions time
and yield
Hydroformylation
Palladium-catalyst
Heck reaction
Palladium-catalyst
Suzuki cross coupling
reaction
Friedal-craft and
Grignard reactions
Pharmaceutical agents
Good electrochemical
cathodic stabilities
Low melting point and
viscosity
Stability in reductive
and oxidative
conditions
Low viscosity
Easy synthesis
Thermally stable upto
400°C
Stability, reactivity and
catalytic role are still to
be recognized

6. Applications of Ionic liquids

7. Investigate Environmental factor and
efficiency of ILs synthesis
Environmental factor (E-factor)
The ratio of weight of waste per unit product
Atom economy
The ratio mass of atoms of product and mass of atoms of
reactants
Energy Consumption
Deetlefs and seddon, 2010 Evaluated greenness of lab-scale IL synthesis and proved that
the synthesis of 1-alkyl- 3-methylimidazolium halide is 100
percent atom efficient due to no formation of by-product.
1-alkyl-3-methylimidazolium halide salts in organic solvent and
excess of alkyl halide results in undesirable value, while the 1-
alkyl-3-methylimidazolium halide salts purification also yields
poor E-factor.
Conventional process for the quaternization step take 24-48 h at
elevated temperature (50-80°C) need considerable energy input
which is inappropriate from economical and environmental
point of view

8. “Before we can say that ionic liquids are green, we have to
look at their entire life cycle. People are calling ionic
liquids green because they are not volatile, but we have to
look at how they are made all the way through to recycling
and disposal”

9. Attri et al. (2010) • Recovered ILs from binary mixtures of ILs/N,N-dimethyl formamide
(DMF) by the removal of the DMF component under vacuum.
• No appreciable change in the physical properties of the recovered ILs
was
observed and the recovered ILs were reused at least four times
without loss of their purity.
Kanel (2003) Mentioned methods developed for recovery of ILs like :
• Heating or evaporation of volatiles under vacuum
• Supercritical CO2 extraction
• Distillation/stripping of the solute from ILs (for thermally stable ILs)
Separation of solutes
from ionic liquids by
distillation/stripping
• Distillation can be used to recover ILs from compounds with low
boiling points, because of the ILs negligible vapor pressure
Extraction with
supercritical CO2
(scCO2)
The unique property of (scCO2):
• Solutes can be separated from ILs without contamination of gas
phase

11. bmpy][N(Tf)2 : 1-butyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide

12. “The best solvent for any process step is
bad for the next step”

13. • Helps in organic synthesis and separation by eliminating the demand to remove and
change solvents after reaction steps
• Enables the application of same solvent for several reaction or separation steps
• Application of solvents is a challenge in chemical industries for green chemical
processing
• Using different solvents to solvate the processing steps increases costs

14. The “switching” of a
switchable solvents

15. Synthesize of switchable ionic liquids (SWILs) using 2,2,2-Trifluoroethanol
(TFE;99%),2,2,3,3-tetrafluoro-1-propanol(TFP;99%),1,8-diazabicyclo-[5.4.0]-undec-
7-ene(DBU;98%),1,1,3,3-tetramethyguanidine(TMG;99%)and phenolphthalein (99%),
Nile Red (99.5%), analytical grade heptane and CO2.

16. Switchable polarity images of four switchable polarity of ionic liquids with a CO2
as the gas trigger: (a)[DBUH][TFE],(b)[TMGH][TFE],(c)[DBUH][TFP], and
(d) [TMGH][TFP].

17. Miscibility of four
SWILs with
conventional
solvents before and
after CO2 bubbling
at room
temperature

18. Polarities of SWILs in low
polarity and high polarity
form as indicated in the
solvatochromic dye nile red.
Regenerated SWILs was
obtained by heating
fluoroalkylcarbonate ILs for
2.5 h at 65°C ∆λmax was
shift of λmax value in the
absence and presence of
CO2

19. Prepared as two-liquid component mixtures, either 1,8-
diazabicyclo-[5.4.0]-undec-7-ene DBU and an alcohol shown
in figure below or DBU and a primary amine

20. Primary and secondary amines react with CO2 to
produce carbamate salts via carbamic acid.

21.  SWILs reduces the requirement to add and remove multiple solvents
 Easy separation of product
 Ability to recycle
 Synthesis of ionic liquids requires CO2 which is cheap and less toxic
 Reduces the cost
 Decreases environmental issues of industries

22.  ILs continue to be an important medium for catalysts for many reactions.
 Effect of water content, contaminant sensitivity, thermal stability, life-cycle costs,
recyclable data, are significant in determining commercial applications of ILs.
 Reuse of ILs is limited to a precise number of cycles when the concentration of
contaminant makes them unusable for a particular motive and converts them into waste.
 Hence it is important to determine an appropriate solution of disposal
 Understanding the transformation of degraded products and their economic and
environmental impacts is significant for designing

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