Chapter 5 - Spectroscopy Flashcards
An IR graph that shows a peak of 1700 indicates a compound with what functional group?
carbonyl
An IR graph that shows a large, broad trough to the left of 3000 indicates a compound with what functional group?
OH
What will the IR graph look like for a compound with a COOH?
a widened and shorter peak on top of the OH trough around 3000
If an IR graph shows “vampire teeth” around 1500-1600 or from 1300-1400, this indicates a ____ group
NO2
A sharp peak to the left of 3000 will indicate a ____ group
NH
1 peak for NH, 2 peaks for NH2
a medium sized peak around 2200 will indicate a ______ group
nitrile
What is UV vis used for?
analyze compounds with conjugated double bonds
Degrees of Unsaturation Formula
Degrees of unsaturation = 2C + 2 + N - H - X
_______________
2
When determining degrees of unsaturation, triple bonds will count as ____ degree, and ring will count as ___ degree
2, 1
Where would alkanes, alkenes, and aromatics show up in NMR spectroscopy?
*types of carbons
alkanes - 0 to 70
alkenes - 90 to 120
aromatics - 110 to 160
Where would carbonyls, aldehydes, and ketones show up in NMR spectroscopy?
carbonyls - 160 to 180
aldehydes and ketones - greater than 200
H’s stuck to sp3 hybridized atoms (such as in CH3, CH2, CH groups) will be found where on H-NMR?
Where would H’s in a C=C double bond be found?
H’s on an aromatic ring?
H’s in sp3 hybridized atoms = 1 to 5 ppm
H’s in C=C double bond = 4 to 6 ppm
Aromatic H’s = 6 to 8 ppm
Where would the following hydrogens be found on H-NMR?
Aldehyde
Carboxylic acid
Phenol
Amide
aldehyde and and phenol H’s = approximately 10 ppm
COOH = 12 to 14 ppm
Amide = 11 to 13
Where would the following hydrogens be found on H-NMR?
Alcoholic OH’s
Amine
0.5 to 5.5 ppm
