Why water cannot be used as solvent in IR Spectroscopy
Stronger hydrogen bonding brings down the frequency shifts and besides it absorbs in UV region.
Why water cannot be used as solvent in IR Spectroscopy
Introduction:
Infrared spectroscopy is a technique that uses the infrared region of the electromagnetic spectrum to identify and study the vibrational modes of molecules. One of the essential components of IR spectroscopy is a solvent that can dissolve the sample and allow for accurate analysis. While many solvents can be used in IR spectroscopy, water is not an ideal solvent for this technique.
Polar nature of water:
One of the primary reasons that water cannot be used as a solvent for IR spectroscopy is its polarity. The polarity of water makes it a strong absorber of infrared radiation, which makes it difficult to distinguish between the sample and the solvent. This can lead to overlapping signals and inaccurate results.
O-H stretching vibration:
Another reason that water cannot be used as a solvent in IR spectroscopy is that its O-H stretching vibration overlaps with many of the vibrational modes of interest in the infrared region. This can make it challenging to identify and analyze the vibrational modes of the sample accurately.
Interference with sample:
Water can also interfere with the sample in other ways. For example, water can form hydrogen bonds with many compounds, which can alter the vibrational modes and make them difficult to identify accurately. Water can also affect the solubility of the sample, which can impact the ability to obtain accurate results.
Conclusion:
In conclusion, water is not an ideal solvent for IR spectroscopy due to its polarity, O-H stretching vibration, and interference with the sample. While many other solvents can be used in IR spectroscopy, it is essential to choose an appropriate solvent that will not interfere with the sample and will allow for accurate analysis.