Carbon tetrachloride (CCl4):
- Transparent in the IR region (except for a weak band around 780 cm-1).
- Suitable for non-polar and slightly polar samples.
- Inert and does not interact strongly with most samples.
Chloroform (CHCl3):
- Transparent in the IR region (except for a few weak bands).
- Good solvent for a wide range of organic compounds.
- Can interact with polar groups through hydrogen bonding.
Methylene chloride (CH2Cl2):
- Similar characteristics to chloroform.
- May be preferred over chloroform for certain samples due to differences in solubility and interactions.
Acetonitrile (CH3CN):
- Transparent in the mid-IR region, but has strong absorption in the far-IR region.
- Polar solvent, suitable for polar samples.
- Can form hydrogen bonds with functional groups.
Methanol (CH3OH):
- Has a broad absorption band in the OH stretching region (around 3300 cm-1).
- Suitable for samples that are soluble in polar solvents.
- May interact with polar groups through hydrogen bonding.
Water (H2O):
- Strong absorption in the OH stretching region (broad band around 3200-3500 cm-1) and bending region (around 1640 cm-1).
- Useful for studying aqueous samples or samples with strong interactions with water.
Deuterated solvents (CDCl3, CDCl2, etc.):
- Isotopically substituted solvents that contain deuterium (D) instead of hydrogen (H).
- Useful for avoiding interferences from strong C-H stretching bands in the spectrum.
It is essential to choose a solvent that is compatible with the sample, does not interfere with the analysis, and provides good solubility. Additionally, the solvent's transparency in the desired spectral region is crucial to ensure accurate and reliable IR measurements.
