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The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500...

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The C=O stretching frequency aldehydes and ketones
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Page 1: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

The C=O stretching frequency

aldehydes and ketones

Page 2: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

C=O aldehydes R(C=O)H 1740-1720 S(sh) 14 ketones R(C=O)R 1730-1710 S(sh) 35 esters R(CO2)R 1750-1735 S(sh) 33, 34 carboxylic acids RCO2H 1720-1680 S(sh) 26,27,30 amides (Amide I) RCONH2, RCONHR 1670-1640 S(sh) 19, 21 (Amide II) RCONH2 1650-1620 S(sh) 19, 21 (Amide II) RCONHR 1550 S(sh) 19, 21 amide RCONR2 1650-1620 S(sh) 23 anhydrides R(CO2CO)R 1820, 1750 S, S(sh) 36 carboxylates R(CO2)-, M+ 1600, 1400 S,S(sh) 42 C=C olefins R2C=CR2 1680-1640 W(sh) 10, 39, 40 R2C=CH2 1600-1675 M(sh) 9, 35 R2C=C(OR)R 1600-1630 S(sh) 41 -NO2 nitro groups RNO2 1550, 1370 S,S(sh) 28

A summary of the principle infrared bands and their assignments. R is an aliphatic group.

Page 3: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Wavenumbers, cm-1

5001000150020002500300035004000

% T

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H-C=OImpurity peak,probably O-H

Figure IR-14. Butanal, neat liquid, thin film: CH3 CH2 CH2 CHO

Aliphatic Aldehyde

1730 cm-1

Page 4: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Wavenumbers, cm-1

5001000150020002500300035004000

% T

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Figure IR-35. 5-Hexene-2-one, neat liquid: CH2 =CH2 CH2 CH2 COCH3

Aliphatic Ketone

1715 cm-1

Page 5: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

The C=O stretching frequency

esters

Page 6: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

C=O aldehydes R(C=O)H 1740-1720 S(sh) 14 ketones R(C=O)R 1730-1710 S(sh) 35 esters R(CO2)R 1750-1735 S(sh) 33, 34 carboxylic acids RCO2H 1720-1680 S(sh) 26,27,30 amides (Amide I) RCONH2, RCONHR 1670-1640 S(sh) 19, 21 (Amide II) RCONH2 1650-1620 S(sh) 19, 21 (Amide II) RCONHR 1550 S(sh) 19, 21 amide RCONR2 1650-1620 S(sh) 23 anhydrides R(CO2CO)R 1820, 1750 S, S(sh) 36 carboxylates R(CO2)-, M+ 1600, 1400 S,S(sh) 42 C=C olefins R2C=CR2 1680-1640 W(sh) 10, 39, 40 R2C=CH2 1600-1675 M(sh) 9, 35 R2C=C(OR)R 1600-1630 S(sh) 41 -NO2 nitro groups RNO2 1550, 1370 S,S(sh) 28

A summary of the principle infrared bands and their assignments. R is an aliphatic group.

Page 7: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Wavenumbers, cm-1

5001000150020002500300035004000

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Top: CHCl3 vs CHCl3

Bottom: 2.5 % v/v un CHCl3

Aliphatic Ester

Figure IR-33. Methyl acetate in 0.1 mm NaCl cells: CH3 CO2 CH3

1720 cm-1

Page 8: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Wavenumbers, cm-1

5001000150020002500300035004000

% T

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Top: CHCl3 vs CHCl3

Bottom: 2.5 % v/v un CHCl3

CCl4 neat1746 cm-1

1748 cm-1

1720 cm-1

Page 9: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Wavenumber, cm-1

1000150020002500300035004000

% T

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liquid film

vapor: 106 °C

Figure IR-34. Vapor and liquid spectra of ethyl n-hexanoate: CH3 CH2 CH2 CH2 CH2 CO2 CH2 CH3

Aliphatic EsterThe effect of phase on IR frequencies

Page 10: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

The C=O stretching frequency

aliphatic acids

Page 11: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

C=O aldehydes R(C=O)H 1740-1720 S(sh) 14 ketones R(C=O)R 1730-1710 S(sh) 35 esters R(CO2)R 1750-1735 S(sh) 33, 34 carboxylic acids RCO2H 1720-1680 S(sh) 26,27,30 amides (Amide I) RCONH2, RCONHR 1670-1640 S(sh) 19, 21 (Amide II) RCONH2 1650-1620 S(sh) 19, 21 (Amide II) RCONHR 1550 S(sh) 19, 21 amide RCONR2 1650-1620 S(sh) 23 anhydrides R(CO2CO)R 1820, 1750 S, S(sh) 36 carboxylates R(CO2)-, M+ 1600, 1400 S,S(sh) 42 C=C olefins R2C=CR2 1680-1640 W(sh) 10, 39, 40 R2C=CH2 1600-1675 M(sh) 9, 35 R2C=C(OR)R 1600-1630 S(sh) 41 -NO2 nitro groups RNO2 1550, 1370 S,S(sh) 28

A summary of the principle infrared bands and their assignments. R is an aliphatic group.

Page 12: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Aliphatic Acid

Figure IR-26. The liquid,

vapor and CCl4 soln

spectra of hexanoic acid:

CH3 (CH2 )4 CO2 H

Wavenumber, cm-1

1000150020002500300035004000

% T

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liquid film

vapor: 134 °C

1710 cm-1

Page 13: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

The C=O stretching frequency

aliphatic amides

Page 14: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

C=O aldehydes R(C=O)H 1740-1720 S(sh) 14 ketones R(C=O)R 1730-1710 S(sh) 35 esters R(CO2)R 1750-1735 S(sh) 33, 34 carboxylic acids RCO2H 1720-1680 S(sh) 26,27,30 amides (Amide I) RCONH2, RCONHR 1670-1640 S(sh) 19, 21 (Amide II) RCONH2 1650-1620 S(sh) 19, 21 (Amide II) RCONHR 1550 S(sh) 19, 21 amide RCONR2 1650-1620 S(sh) 23 anhydrides R(CO2CO)R 1820, 1750 S, S(sh) 36 carboxylates R(CO2)-, M+ 1600, 1400 S,S(sh) 42 C=C olefins R2C=CR2 1680-1640 W(sh) 10, 39, 40 R2C=CH2 1600-1675 M(sh) 9, 35 R2C=C(OR)R 1600-1630 S(sh) 41 -NO2 nitro groups RNO2 1550, 1370 S,S(sh) 28

A summary of the principle infrared bands and their assignments. R is an aliphatic group.

Page 15: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Amide I 1662 cm-1

Amide II; 1634 cm-1

KBr pellet

Page 16: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Wavnumbers, cm-1

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Amide I Amide II

Figure IR-21. N-Methyl acetamide, neat liquid; thin film: CH3 CONHCH3

Secondary Amide

Page 17: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Wavenumbers, cm-1

5001000150020002500300035004000

% T

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Figure IR-23. N,N-Dimethylacetamide, neat liquid; thin film: CH3 CON(CH3 )2

Tertiary Amide

No amide II band

Page 18: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

The C=O stretching frequency

anhydrides

Page 19: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

C=O aldehydes R(C=O)H 1740-1720 S(sh) 14 ketones R(C=O)R 1730-1710 S(sh) 35 esters R(CO2)R 1750-1735 S(sh) 33, 34 carboxylic acids RCO2H 1720-1680 S(sh) 26,27,30 amides (Amide I) RCONH2, RCONHR 1670-1640 S(sh) 19, 21 (Amide II) RCONH2 1650-1620 S(sh) 19, 21 (Amide II) RCONHR 1550 S(sh) 19, 21 amide RCONR2 1650-1620 S(sh) 23 anhydrides R(CO2CO)R 1820, 1750 S, S(sh) 36 carboxylates R(CO2)-, M+ 1600, 1400 S,S(sh) 42 C=C olefins R2C=CR2 1680-1640 W(sh) 10, 39, 40 R2C=CH2 1600-1675 M(sh) 9, 35 R2C=C(OR)R 1600-1630 S(sh) 41 -NO2 nitro groups RNO2 1550, 1370 S,S(sh) 28

A summary of the principle infrared bands and their assignments. R is an aliphatic group.

Page 20: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Wavenumber, cm-1

50010001500200025003000350040004500

% T

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Figure IR-36. Propionic anhydride, neat liquid: CH3 CH2 CO2 COCH2 CH3

Anhydrides

Page 21: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

The C=O stretching frequency

carboxylates

Page 22: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

C=O aldehydes R(C=O)H 1740-1720 S(sh) 14 ketones R(C=O)R 1730-1710 S(sh) 35 esters R(CO2)R 1750-1735 S(sh) 33, 34 carboxylic acids RCO2H 1720-1680 S(sh) 26,27,30 amides (Amide I) RCONH2, RCONHR 1670-1640 S(sh) 19, 21 (Amide II) RCONH2 1650-1620 S(sh) 19, 21 (Amide II) RCONHR 1550 S(sh) 19, 21 amide RCONR2 1650-1620 S(sh) 23 anhydrides R(CO2CO)R 1820, 1750 S, S(sh) 36 carboxylates R(CO2)-, M+ 1600, 1400 S,S(sh) 42 C=C olefins R2C=CR2 1680-1640 W(sh) 10, 39, 40 R2C=CH2 1600-1675 M(sh) 9, 35 R2C=C(OR)R 1600-1630 S(sh) 41 -NO2 nitro groups RNO2 1550, 1370 S,S(sh) 28

A summary of the principle infrared bands and their assignments. R is an aliphatic group.

Page 23: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

1410 cm-11560 cm-1

Page 24: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,
Page 25: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

The C=C bond stretch

Page 26: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

C=O aldehydes R(C=O)H 1740-1720 S(sh) 14 ketones R(C=O)R 1730-1710 S(sh) 35 esters R(CO2)R 1750-1735 S(sh) 33, 34 carboxylic acids RCO2H 1720-1680 S(sh) 26,27,30 amides (Amide I) RCONH2, RCONHR 1670-1640 S(sh) 19, 21 (Amide II) RCONH2 1650-1620 S(sh) 19, 21 (Amide II) RCONHR 1550 S(sh) 19, 21 amide RCONR2 1650-1620 S(sh) 23 anhydrides R(CO2CO)R 1820, 1750 S, S(sh) 36 carboxylates R(CO2)-, M+ 1600, 1400 S,S(sh) 42 C=C olefins R2C=CR2 1680-1640 W(sh) 10, 39, 40 R2C=CH2 1600-1675 M(sh) 9, 35 R2C=C(OR)R 1600-1630 S(sh) 41 -NO2 nitro groups RNO2 1550, 1370 S,S(sh) 28

A summary of the principle infrared bands and their assignments. R is an aliphatic group.

Page 27: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,
Page 28: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,
Page 29: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Wavenumbers, cm-1

5001000150020002500300035004000

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HC=Cstretches

CH3,CH2 symmetric and asymmetric stretches

C=Cstretch

CH3,CH2 bending vibrations

(CH2)4

rocking

out of plane H wag of vinylgroup 900, 1000 cm-1)

Figure IR-9. 1-Heptene; neat sample, thin film:

H2 C=CH-CH2 CH2 CH2 CH2 CH3

Page 30: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

The C=C bond stretch when next to a heteroatom

Page 31: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

C=O aldehydes R(C=O)H 1740-1720 S(sh) 14 ketones R(C=O)R 1730-1710 S(sh) 35 esters R(CO2)R 1750-1735 S(sh) 33, 34 carboxylic acids RCO2H 1720-1680 S(sh) 26,27,30 amides (Amide I) RCONH2, RCONHR 1670-1640 S(sh) 19, 21 (Amide II) RCONH2 1650-1620 S(sh) 19, 21 (Amide II) RCONHR 1550 S(sh) 19, 21 amide RCONR2 1650-1620 S(sh) 23 anhydrides R(CO2CO)R 1820, 1750 S, S(sh) 36 carboxylates R(CO2)-, M+ 1600, 1400 S,S(sh) 42 C=C olefins R2C=CR2 1680-1640 W(sh) 10, 39, 40 R2C=CH2 1600-1675 M(sh) 9, 35 R2C=C(OR)R 1600-1630 S(sh) 41 -NO2 nitro groups RNO2 1550, 1370 S,S(sh) 28

A summary of the principle infrared bands and their assignments. R is an aliphatic group.

Page 32: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Wavenumbers, cm-1

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Figure IR-40. 2,5-Dimethoxy2,5-dihydrofuran, neat liquid:

O OCH3CH3O

Page 33: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Wavenumbers, cm-1

5001000150020002500300035004000

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Figure IR-41. 2,3-Dihydrofuran, neat liquid:O

1610 cm-1

Page 34: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

1652 cm-1

Page 35: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

The cumulative C=C bond stretch

Page 36: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

1958 cm-1

Page 37: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

The NO2 stretching frequency

Page 38: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

C=O aldehydes R(C=O)H 1740-1720 S(sh) 14 ketones R(C=O)R 1730-1710 S(sh) 35 esters R(CO2)R 1750-1735 S(sh) 33, 34 carboxylic acids RCO2H 1720-1680 S(sh) 26,27,30 amides (Amide I) RCONH2, RCONHR 1670-1640 S(sh) 19, 21 (Amide II) RCONH2 1650-1620 S(sh) 19, 21 (Amide II) RCONHR 1550 S(sh) 19, 21 amide RCONR2 1650-1620 S(sh) 23 anhydrides R(CO2CO)R 1820, 1750 S, S(sh) 36 carboxylates R(CO2)-, M+ 1600, 1400 S,S(sh) 42 C=C olefins R2C=CR2 1680-1640 W(sh) 10, 39, 40 R2C=CH2 1600-1675 M(sh) 9, 35 R2C=C(OR)R 1600-1630 S(sh) 41 -NO2 nitro groups RNO2 1550, 1370 S,S(sh) 28

A summary of the principle infrared bands and their assignments. R is an aliphatic group.

Page 39: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

N

O

O

+N

O

O

+-

-

1556 cm-1 1367 cm-1

Page 40: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Wavenumbers, cm-1

5001000150020002500300035004000

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symmetric and asymmetric-NO2 stretch

4-Chloro-2-nitrophenol, KBr pellet:

1510 and 1320 cm-1

Page 41: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Aromatic Rings

Ring breathing motions

1600-1585

1500-1400

Both often appear as doublets

Page 42: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Wavenumbers, cm-1

5001000150020002500300035004000

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carbon-carbontriple bond stretch

H

Page 43: The C=O stretching frequencychickosj/c365/lectureIR2.pdf · Wavenumbers, cm-1 4000 3500 3000 2500 2000 1500 1000 500 % Transmittance 0 20 40 60 80 100 Figure IR-35. 5-Hexene-2-one,

Wavenumbers, cm-1

5001000150020002500300035004000

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overtones of the benzene ring

Benzene, neat, thin film:


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