What is Effect of Solvent on UV Absorption Spectra | Spectroscopy | Organic Chemistry
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5 سال پیش
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Solvents used in preparation of
Solvents used in preparation of sample for UV spectra can be of two types, Polar and Non Polar.
Polar solvents like ethyl alcohol have electronegative atom with lone pair of electrons or non bonding electrons. This non bonding electron can form solute-solvent complexes through H-bonding, hence, if the lone pair of electrons is in conjugation with the chromophoric group, the 𝛌max increases to higher value.
Also it is seen that the polar solvents or solvents interacting with sample molecules diminishes the hyper fine structure of UV spectra. That means peaks become broad.
Non-polar solvents do not form H- bond with solute, so “fine structure” is often observed. Which is called hyper fine peak structure.
Basic Requirement:
1. Solvent should not absorb UV light in the region where our sample is absorbing, else peaks will overlap.
2. Solvent should not interact chemically with the sample molecules, even small hydrogen bonds affect the peak position and its width.
3. If possible avoid the use of polar solvents as they interact with chromophoric groups.
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Polar solvents like ethyl alcohol have electronegative atom with lone pair of electrons or non bonding electrons. This non bonding electron can form solute-solvent complexes through H-bonding, hence, if the lone pair of electrons is in conjugation with the chromophoric group, the 𝛌max increases to higher value.
Also it is seen that the polar solvents or solvents interacting with sample molecules diminishes the hyper fine structure of UV spectra. That means peaks become broad.
Non-polar solvents do not form H- bond with solute, so “fine structure” is often observed. Which is called hyper fine peak structure.
Basic Requirement:
1. Solvent should not absorb UV light in the region where our sample is absorbing, else peaks will overlap.
2. Solvent should not interact chemically with the sample molecules, even small hydrogen bonds affect the peak position and its width.
3. If possible avoid the use of polar solvents as they interact with chromophoric groups.
Ask a question at http://bit.ly/2GrIMbs
Answer a question at http://bit.ly/2V26gM5
Other Subjects:
Adult Education @ http://bit.ly/2KFPK0s
Analytical Chemistry @ http://bit.ly/2Gq24Ok
Applied Physics @ http://bit.ly/2Xh4S64
Engineering Drawing @ http://bit.ly/2IHro43
English @ http://bit.ly/2V8FSk4
Environmental Studies @ http://bit.ly/2UGKlLa
General Medicine @ http://bit.ly/2Gtn8Uh
Mathematics @ http://bit.ly/2UEZVqH
Organic Chemistry @ http://bit.ly/2GkXvTY
Physical Chemistry @ http://bit.ly/2v5EQX5
Soft Skills @ http://bit.ly/2Zf6wa3
5 سال پیش
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