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53 Cards in this Set
- Front
- Back
Ifmolecule contains only C, H and O - How do you calculate DBE? |
CaHbOc - DBE = [(2a + 2) - b]/ 2 |
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How do trivalent atoms alter the DBE? |
Count monovalent atoms (Cl, Br etc) ashydrogens and add them to b Count trivalent atoms (N, P etc) asd CaHbOcNd - DBE = [(2a + 2) - (b - d)]/2 |
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If ε is high – electronic transition occurs? |
If ε is high – electronic transition occurs readily. |
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If ε is low – electronic transition ... ? |
If ε is low – electronic transition does not occur readily. |
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What is an "allowed" ε transition? |
ε > x103 ‘allowed’ transition |
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What is a "forbidden" ε transition? |
ε <100 ‘forbidden’ transition |
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Substituentswhich increase the extinction coefficient are ... ? |
Substituentswhich increase the extinction coefficient are hyperchromic |
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Substituentswhich decrease the extinction coefficient are ... ? |
Substituents which decrease the extinction coefficient are hypochromic |
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What is the Beer-Lambert Law? |
A= Log(Io/I) = εcL Where: A - Absorbance Io - Intensity of incident light I - Intensity of transmitted light ε - Molar absorptivity c - Concentration in mol/L L - Path length in cm |
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π→π* happens at what wave length? And in what systems? |
λmax ~ 200 nm, conjugated or aromatic systems |
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n → π* happens at what wave length? And in what systems? |
λmax ~300 nm, aldehyde or ketones |
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INFRA-RED -OH ? |
Broad absorption - 3000-3500 |
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INFRA-RED ≡C-H ? |
Sharp and strong ~3300 |
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IR C-H? Sp2/Sp3?? |
- 2700 -3100 strong for sp3, weaker for sp2 |
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IR COOH |
Broad - 2500-3500 |
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IR Aldehyde? Confirmed at what peak? |
1690-1750 confirmed by C-H ~2700-3100 |
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IR Ester? Confirmed by? |
1735 - 1750 confirmed by C-O ~1000-1300 |
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IR
C=C,C=N? |
1500-1650 |
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IR C=C,Aromatic? |
~1600 |
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IR NO2 |
Strong ~ 1550 |
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IR N-H |
Broad, - 3000-3500 |
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IR Amide? |
1690-1700 |
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IR C-O |
1000-1300, if strong alcohol/ester/ether |
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2Jab is what coupling? |
Geminal |
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3Jab is what coupling? |
Vicinal |
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4Jab is what coupling? |
Long Range |
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C13 R-CH3 |
8-35 |
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C13 R-CH2-R |
15-50 |
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C13 R-CH-(R)2 |
20-60 |
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C13 (R)4C |
30-40 |
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C13 TRIPLE - C |
65-85 |
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C13 = C |
100-150 |
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C13 BENZENE C |
110-170 |
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C13 C-N |
40-60 |
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C13 AMIDE |
165-175 |
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C13 ESTER |
165-175 |
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C13 COOH |
175-185 |
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C13 ALDEHYDE |
190-200 |
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C13 KETONE |
200-250 |
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H1 CH3R |
0.8-1.2 |
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H1 RCH2R |
1-1.5 |
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RCHRR |
1.2-1.8 |
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H1 C=CCH2 |
2-3 |
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H1 N-CH3 |
2.3-3.3 |
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H1 O-CH3 |
3.4-4 |
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H1 C=CH |
5-8 |
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H1 AROMATIC |
6-9 |
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H1 CH=O |
9-10 |
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H1 COOH |
10-12 |
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H1 R-OH |
2-5 |
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H1 RNH2 |
3-5 |
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H1 CH3CN |
2 |
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H1 BENZENE |
~7 |