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Organic Chemistry Laboratory II EXAMPLE IR AND NMR (#1) 16-IR and NMR Analysis 100 WAVEHUMBER CM* 630 425 4000 3000 2300 2000 1300 1309 1100 1000 900 800 700 90 70 60 30 40 30 20 10 о 2.5 3 ก S NEAT Pappas and Goicoechea-Pappas 20 10 11 12 13 Aldrich Chemical Company 14 15 16 WAVELENGTH IN MICRONS 100 16-8 Scanned with CamScanner Organic Chemistry Laboratory II IR and NMR ANALYSIS CHM 2211L 16-IR and NMR Analysis MODULE 16 NAME Example 1 YOU MUST SUPPORT YOUR REASONING BY FILLING IN ALL BLANKS Major Functional Group Analysis carboxylic acid, amide (primary or secondary), aldehyde, ester, ketone, alcohol, phenol, amine (primary or secondary), terminal alkyne, or nitrile. O || (6) Major Functional Group Present: - C-OR (ester) Reasoning using IR spectrum: Give specific location of absorption(s) Reasoning using NMR spectrum: Only RCOOH and RCHO need justification. Minor Functional Group Analysis @ 1754 cm¯ and C-O @ 1198 cm Indicate the presence or absence of each of the following minor functional groups, by placing an A for Absent, P for Present, or M for Maybe in the space provide. You must include your justification. (6) Aromatic Group Presence IR Peak(s) indicating Presence or Absence = C-H @ 3021 cm- (due to alkene) Absent no 1575-1625 cm- (157 1475 1525 cm- If aromatic, type of substitution (mono, ortho, meta, para): Reasoning: (4) Alkene Group Presence Present IR Peak(s) indicating Presence or Absence = C H @ 3021 cm¯ C=C @ 1666 cm- Pappas and Goicoechea-Pappas NMR Peak(s) indicating Presence or Absence no peaks in NMR between 6.0 - 9.5 ppm NMR Peak(s) indicating Presence or Absence peak @ 4.6 ppm 16-9 Scanned with CamScanner Organic Chemistry Laboratory II Н R₁ H 16- IR and NMR Analysis Ro" or RCC or RC-CH C=C Η H 'R _ R R If alkene, type of substitution: H H R H R H C=C C=C H´ H H H H H R R' R R 900 cm¯ R 963 cm- Η H Reasoning: C= C 833 cm- -->{-- >{\|-->< IR Peak(s) indicating Presence or Absence H R C= R R Group (3) Alkyl (3) Ether (3) Nitro Presence Present Maybe Absent C H@2941 cm- I can't be confirmed due to presence of C-O from ester. no N=O @ 15151560 cm & @ 1345 1385 cm- NMR Analysis (4) 1. How many different types of protons are there? 3 Reasoning: There are 3 different peaks (singlets) (5) 2. Give the area (proton ratio) for each signal. (When the signal is split, consider the center of the signal to denote its location) 1. Peak @ 4.6 ppm ---> Area = 2 4. Peak @ ppm -> Area = 2. Peak @ 2.1 ppm- ---> Area = 3 5. Peak @ ppm ---> Area = 3. Peak @ 1.9 ppm ---> Area = 3 6. Peak @ ppm ---> Area = (6) 3. Taking all the above information into account, draw the structural formula for the compound. R H R R is eliminated because the NMR indicates that there are 2 alkene protons and this would only have one. H C' Η is eliminated because the alkene protons from this type of R molecule would be split and no splitting is seen in NMR. Since all 3 signals are singlets, we must come up with a structure in which the C's have no adjacent H's. Pappas and Goicoechea-Pappas 2.1 ppm CH3-C. бот 4.6 ppm CH 3 1.9 ppm 16-10 Scanned with CamScanner Organic Chemistry Laboratory II EXAMPLE IR AND NMR (#2) 16-IR and NMR Analysis 4000 3000 2300 2000 2000 1900 1300 1100 1000 900 WAVENUMBER CM 700 650 625. 30 10 DEAT 100 80 500 400 300 Pappas and Goicoechea-Pappas ° Aldrich Chemical Company 12 13 100 90 10 16 14 15 WAVELENGTH IN MICRONS 16-11 Scanned with CamScanner Organic Chemistry Laboratory II IR and NMR ANALYSIS CHM 2211L 16-IR and NMR Analysis MODULE 16 NAME Example 2 YOU MUST SUPPORT YOUR REASONING BY FILLING IN ALL BLANKS Major Functional Group Analysis carboxylic acid, amide (primary or secondary), aldehyde, ester, ketone, alcohol, phenol, amine (primary or secondary), terminal alkyne, or nitrile. (6) Major Functional Group Present: -OH (phenol or aromatic alcohol) Reasoning using IR spectrum: Give specific location of absorption(s) -OH @ 3448 cm (broad) and =C-H @3040 cm and benzene ring @ 1587 cm and 1492 cm Reasoning using NMR spectrum: Only RCOOH and RCHO need justification. Minor Functional Group Analysis Indicate the presence or absence of each of the following minor functional groups, by placing an A for Absent, P for Present, or M for Maybe in the space provide. You must include your justification. (6) Aromatic Group Presence Present IR Peak(s) indicating Presence or Absence = C H @ 3040 cm¯ 1587 cm- 1492 cm- NMR Peak(s) indicating Presence or Absence multiplet centered @ 7 ppm If aromatic, type of substitution (mono, ortho, meta, para): ortho or para Reasoning: 749 cm (ortho) ог 837 cm (para) (4) Alkene Group Presence Absent IR Peak(s) indicating Presence or Absence = C H @ 3040 cm no C = C @ 1630-1680 cm- NMR Peak(s) indicating Presence or Absence peak @ 4.7 is in alkene region, but upon further examination it is due to the -OH Pappas and Goicoechea-Pappas 16-12 Scanned with CamScanner