Could someone please explain the difference between these. I understand that each gives a different baseline shift (a \"lock\" for the NMR machine), but why would one be better than another?
b. D2O, CDCIs, and DMSO-ds are common deuterated solvents used for NMR analysis. If the Chem 30BL student had isolated the HCl salt of compound J above, which of these solvents should s/he use for NMR analysis. Circle the answer (2 points). D20 CDCl3 DMSO-d
Solution
Cost wise D2O is cheapeast, followed by CDCl3 and most expensive is DMSO-d6
But D2O peaks may shift and is not stable in position in NMR, whereas CDCl3 and DMSO-d6 peaks come at a specific position only.
Most compounds dissolve easily in DMSO and therefore it is better solvent if the compound is stable in DMSO (aqueous conditions). But compounds dissolved in DMSO are difficult to recover. On the other hand CDCl3 most commonly used solvent for NMR is essy to use and compounds once dissolved are recoverable easily. Thus CDCl3 is preferred in most cases followed by DMSO (wherein compound has less solubility in CDCl3).
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Could someone please explain the difference between these- I understan.docx
1. Could someone please explain the difference between these. I understand that each gives a
different baseline shift (a "lock" for the NMR machine), but why would one be better than
another?
b. D2O, CDCIs, and DMSO-ds are common deuterated solvents used for NMR analysis. If the
Chem 30BL student had isolated the HCl salt of compound J above, which of these solvents
should s/he use for NMR analysis. Circle the answer (2 points). D20 CDCl3 DMSO-d
Solution
Cost wise D2O is cheapeast, followed by CDCl3 and most expensive is DMSO-d6
But D2O peaks may shift and is not stable in position in NMR, whereas CDCl3 and DMSO-d6
peaks come at a specific position only.
Most compounds dissolve easily in DMSO and therefore it is better solvent if the compound is
stable in DMSO (aqueous conditions). But compounds dissolved in DMSO are difficult to
recover. On the other hand CDCl3 most commonly used solvent for NMR is essy to use and
compounds once dissolved are recoverable easily. Thus CDCl3 is preferred in most cases
followed by DMSO (wherein compound has less solubility in CDCl3).
