Flashcards
IR SAS
Cards in this deck (21)
- 1at what frequency do alcohols and phenols absorb?3600-3200 cm-1
very broad - 2at what frequency do carboxylic acids absorb?3000-2500 cm-1
very broad OH stretch superimposed on sharp CH signals - 3at what frequency does N-H absorb3500-3300 cm-1
broad
- primary amines and amides typically show 2 bands - 4at what frequency do sp3 hybridised CH absorb<3000 cm-1
- 5at what frequency do sp and sp2 hybridised CH>3000 cm-1
- 6at what frequency does aldehydic CH absorb2900-2700 cm-1
often 2 bands - 7at what frequency does SH absorb2600-2550 cm-1
weak and not as broad as OH - 8at what frequency does C=C absorbNON CONJUGATED
1680-1620 cm-1
weak/medium
CONJUGATED
lowered by 40 cm-1 - 9whats the range of frequencies C=O absorbs at1
- 10at what frequency does acid chloride C=O1800cm-1
- 11at what frequency does anhydride C=Otwo bands
1820 and 1750 cm-1 - 12at what frequency does ester C=O1750-1735 cm-1
- 13at what frequency does aldehydic C=O1740-1720 cm-1
- 14at what frequency does ketone C=O1720-1705 cm-1
- 15at what frequency does carboxylic acid C=O1725-1700 cm-1
- 16at what frequency does amide C=O1700-1670 cm-1
- 17if a carbonyl is conjugated with C=C or phenol what happens to the absorption and what is the exceptionreduced by 20 cm-1
except for amides which increases by 15 cm-1 - 18at what frequency does N-O in NO2 group absorb1600-1500 strong
1400-1300 medium to strong - 19at what frequency does C-O absorb1300-1000 cm-1
medium-strong - 20at what frequency does C-Cl absorb800-600 cm-1
- 21whats the effect of ring size on cyclic ketone absorptionas the ring size decreases the absorption increases as the sp3 hybridised carbons have increased p character due to constraints in smaller rings, this is compensated for by an increase in s characted by carbonyl bond. increase in bond energy for carbonyl group as s orbitals are lower lying than p orbitals
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- Chemistry (sas) Flashcards on IR SAS, created by Casey Champion on 23/04/2023.
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- Casey Champion
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