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12 Nov 2019
Organic chemistry lab- CNMR question. For # 4, peaks are on the left that need to be placed correctly in the table.
2-Triluoroaceame Esters C. SPECTROSCOPIC ANALYSIS, 16 POINTS NMR SPECTROSCOPY, 12pts 1. Record the letter of your assigned alcohol unknown pt 2. Draw your ester and label carbons on the structure. Label the CF3 carbon "a" and the carbonyl carbon·b" Label the remaining carbons with letters of the alphabet as they are removed from the carbonyl- an example using the ester of 1-butanol is shown. 2 pts Example Drawing Drawing of your trifluoroester labeled for NMR 3. How many peaks are reported for the CNMR of your unknown ester? 4. Using CNMR data provided complete the table identifying the CNMR Shifts of the each labeled carbon in your drawing above. (Note you may only have 5 unique carbons) 2 pts Carbon Chemical shift (ppm) Carbon Chemical shift (ppm) letter Ca Cb Ce Cd Ce cr 5. The provided data for CNMR of the ester show that two carbon peaks in each ester are quartets. Can you explain why these carbons appear as quartets in CNMR? 2pts E quortct. 6. Besides your unknown, list three additional alkyl groups from Table 2 that can produce a trifluoroacetate ester with the same number of CNMR peaks as your unknown. 2 pts 7. Attach a labeled IH NMR spectrum of your ester. Identify the protons on your HINMR with corresponding letters of their carbon on your drawing above. For the example above the terminal methyl protons would be labeled "f" on the HNMR. 2 pts
Organic chemistry lab- CNMR question. For # 4, peaks are on the left that need to be placed correctly in the table.
2-Triluoroaceame Esters C. SPECTROSCOPIC ANALYSIS, 16 POINTS NMR SPECTROSCOPY, 12pts 1. Record the letter of your assigned alcohol unknown pt 2. Draw your ester and label carbons on the structure. Label the CF3 carbon "a" and the carbonyl carbon·b" Label the remaining carbons with letters of the alphabet as they are removed from the carbonyl- an example using the ester of 1-butanol is shown. 2 pts Example Drawing Drawing of your trifluoroester labeled for NMR 3. How many peaks are reported for the CNMR of your unknown ester? 4. Using CNMR data provided complete the table identifying the CNMR Shifts of the each labeled carbon in your drawing above. (Note you may only have 5 unique carbons) 2 pts Carbon Chemical shift (ppm) Carbon Chemical shift (ppm) letter Ca Cb Ce Cd Ce cr 5. The provided data for CNMR of the ester show that two carbon peaks in each ester are quartets. Can you explain why these carbons appear as quartets in CNMR? 2pts E quortct. 6. Besides your unknown, list three additional alkyl groups from Table 2 that can produce a trifluoroacetate ester with the same number of CNMR peaks as your unknown. 2 pts 7. Attach a labeled IH NMR spectrum of your ester. Identify the protons on your HINMR with corresponding letters of their carbon on your drawing above. For the example above the terminal methyl protons would be labeled "f" on the HNMR. 2 pts
Lelia LubowitzLv2
15 Jun 2019