1H-NMR SPECTROSCOPY2008

UnknownC4H8O2

1H-NMR

1H-NMR - Theory

3.1 Nuclear Spin States

3.2 Nuclear Magnetic Moments

3.3 Absorption of Energy

1H-NMR - Theory

1H-NMR - Theory

3.4 Absorption / Resonance 3.4 Absorption / Resonance

1H-NMR

3.7 The Spectrometer

The FID (Free Induction Decay)

Fourier Transform (time domain signal converted to frequency domain signal)

1H-NMR – Chemical Shift

Chemical equivalence

Hybridization effects

Electronegativity Effects

Shielding (vs deshielded)

hexane

1H-NMR Chemical Shift

Hybridization effects

Electronegativity Effects

1H-NMR – Chemical Shift

1H-NMR – Chemical Shift

Acidic and Exchangeable Protons - Chemical Shift Ranges

Exchangable proton

Chemical Shift Range (ppm)

Acids RCOOH 10.5 - 12

Phenols ArOH 4.0-7.0

(as high as 9.0)

Alcohols ROH 0.5 – 5.0

Amines RNH2 0.5 – 5.0

Amides RCONH2 5.0 - 9.0

1H-NMR – Chemical ShiftMagnetic Anisotropy (3.12)

1H-NMR – CouplingSpin-Spin Splitting (3.13)

1H-NMR – CouplingSpin-Spin Splitting (3.13)

1H-NMR – CouplingSpin-Spin Splitting (3.13)

1H-NMR – CouplingThe Coupling Constant (3.17)

1H-NMR – CouplingThe Coupling Constant (3.17)

1H-NMR – CouplingThe Coupling Constant (3.17)

1H-NMR – CouplingThe Coupling Constant (3.17)

1H-NMR – Coupling The Coupling Constant (3.17)

C6H5-CH=CH-CO2CH3

C10H10O2

1H-NMR – Coupling - The Coupling Constant (3.17)30

89.

830

73.

8

258

7.6

257

1.6

1H-NMR - Aromatics (3.19C)

1H-NMR4-n-propylphenol

1H-NMR - Aromatics Chemical Shift Calculation

OH

CH2CH2CH3

6.75 vs 7.03 ppm

1H-NMR – Unknown (C6H4Br)

1H-NMR – Unknown (C6H6BrN)

C7H7OBr

1H-NMR – Unknown (C7H7BrO)

Unknown A (C7H14)

Unknown B (C7H14)

1H-NMR – Unknown isomers