N.M.R. Spectroscopy Flashcards

1
Q

What does NMR stand for?

A

Nuclear Magnetic Resonance

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2
Q

What can NMR spectroscopy give details about?

A

The position of 13C or 1H atoms in a molecule

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3
Q

What is used to calibrate the HNMR and CNMR spectrum?

A

TMS (tetramethylsilane) (Si(CH3)4

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4
Q

Why is TMS a suitable standard?

A

Signal away from all the others (strong but only gives one)
Non toxic
Inert/unreactive
Low boiling point (so easy to remove)

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5
Q

Why is CDCl3 a suitable solvent for HNMR, despite an H being present? (deuterium)

A

It is 2^H
As it is an even number, the spins cancel out

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6
Q

Why must samples for HNMR be dissolved in a sample free of H1 atoms?

A

The H1 from the solvent would be present on the reading and so throw it

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7
Q

How are the samples for HNMR spectra obtained?

A

Samples are dissolved in CCl4 (non polar) or deuterated solvents (e.g. CDCl3 (polar) or D2O/heavy water)

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