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Additional Office Hour Time
• Every Thursday, 2-3pm in Mol Sci 4100 (the person leading this office hours will be different each week)
• BEGINS TOMORROW and will go to the end of the quarter
NMR practice problemsSources:Web Spectra:
http://www.chem.ucla.edu/~webspectra/
Spectral Database of Organic Compounds (SDBS)http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/cre_index.cgi
LEGEND:-1H means an integration value of “1”, while 2H means an intergration value of “2” etc.- s = singlet- d = doublet- t = triplet- m = multiplet
Ch14C, Spring 2012Prof. Dong
Rough 1H-NMR guidelines• Aldehyde 10 ppm
• Aromatic 7-9
• Vinylic 5-7
• -OCH3 3-4
• Ketone (α position) 2
• H-C≡C-R 2
• -CH3 0-1
• TMS Si(CH3)4 0 (we use this as reference)
For next several slides, the chemical structure and its 1H-NMR spectra is given to you. Please try to assign as many of the protons to the peaks shown. Confirm the following 4 features:1.Number of equivalent protons2.Chemical shift3.Integration4.Splitting
Also, using the molecular formula, calculate the DBE and confirm that it matches the structure shown
Position of peak on 1H-NMR depends on the “chemical” environment around the proton
• Each of the molecules below give 1 peak on 1H-NMR because all the protons experience the same chemical environment
H2C
H2CCH2
CH2
H2C
H
H
H
H
H
H O
Beginner #7, C14H14
H
H
H
H
H
H H
H H
H
H
H
H
H
10H,m (overlap)
4H,s
Beginner #10, C10H10O2
3H, s
H
O
OCH3
H
H
H
H
H
H
1H,m 1H,m1H,m
1H,m
1H,m1H,m
1H,m
Beginner #12 C6H12O2
H3C
O
O
H2C
CH2
H2C
CH3
3H,s
2H, t 2H,pentet
2H,sextet
3H,t
Beginner #27, C3H7OCl
1H, s2H, t
Cl
H2C
CH2
H2C
OH
2H, t 2H, pentet
Beginner #25, C4H8O
H3C
O
CH2
CH3
2H, q
3H, s3H, t
Int1 #1, C3H4O
O
HH
H
H
1H,d3H (overlapping peaks)
Int2 #13, C10H15N N
H2C
H2C
CH3H3C
H
H
H
H
H
2H,m 3H,m
4H,q
6H,t
Int#12, C7H9NO NH2
OCH3
H
H
H
H
4H,m
2H,s
3H,s