Experiment a groupPeak Observed (PPM)Peak Phase (-/+) 1CH39.12+2CH224.91_3CH262.76_ Propanol

Experiment 1: Identification of unknown alcohol based on 1H and 13C NMR analysisEsther LandeCHM 2211 L Section 002Lab was performed on January 22, 2018                     IntroductionThis experiment was performed to identify an unknown alcohol. The TA set up the spectrometer, the unknown alcohol was provided by our TA and I received sample 1. A pre-run  DEPT- 135 spectrum was also given to us. We used three different types of  NMR spectrums which included 1H NMR, 13C NMR and DEPT- 13C NMR to identify the unknown alcohol a benchtop 42.5 MHz Spinsolve Carbon NMR spectrometer. We evaluated the four components of a 1H (proton) NMR of my sample which included integration,  the number of signals, the chemical shift, and the splitting of the peaks in the spectrum. The peaks observed for unknown sample 1  were of (A)-OH at 4.89 ppm, (B)-CH2 at 3.01 ppm, (C)-CH2 at 1.01 ppm, and (D) -CH2 at 0.43 ppm in the 1H NMR. The 1H NMR spectrum that I obtained for my unknown sample of alcohol contained two signals overlapping and this can be a source of error. The predicted peaks for propanol includes (A)-OH at 4.80 ppm, (B)-CH2 at 3.30 ppm, (C) –CH3CH2 at 1.0 ppm and (D)-CH3CH2 at 0.50 ppm in 1H NMR. The observed peaks for unknown sample 1  in 13C NMR were of (1) –CH3 at 9.06 ppm, (2) -CH2 at 24.84 ppm, and (3) -CH2 at 62.69 ppm. The predicted peaks for propanol in 13C NMR included (1) -CH3 at 17.0 ppm, (2) -CH2 at 24.5 ppm, and (3) – CH2 at 60.0 ppm. Two negative peaks were observed in DEPT- 13C spectrum. The DEPT – 135 spectrum confirmed the  chemical shifts seen at (1) 9.12 ppm for -CH3, (2) at 24.91 ppm for – CH2, and (3)  at 62.76 ppm for -CH2.. Results:Table 1: Figure 1.1H NMR of PropanolAtomAtom is part of a groupPeak multiplicity Peak Observed (PPM)    AOHTriplet4.89BCH2Quartet3.01CCH3 CH2Multiplet overlap1.01 DCH3CH2Multiplet overlap0.43     Table 2: Figure 2. 13C NMR of PropanolAtomAtom is part of a groupPeak Observed (PPM)     1CH39.06 2CH224.84 3CH262.69    Table 3: Figure 3. DEPT – 135 NMR of PropanolAtomAtom is part of a groupPeak Observed (PPM)Peak Phase (-/+)    1CH39.12+2CH224.91_3CH262.76_   Propanol StructurePropanolC3H8O    DiscussionIn table 1, splitting pattern of a triplet peak is  the most downfield signal in the 1H NMR affected  by the 2 H’s in group CH2.The lowest peaks observed in table 1  were multiplets overlapping part of the group CH3CH2. Since there was no clear pattern of spltting, one could conclude that the two of the peak were multiplets. The peaks of 13 C NMR was almost similar to the pre-run DEPT 135 NMR with a slight difference in the number of the peaks observed.  Three different carbon peaks were observed  in the unknown alcohol sample that was given for DEPT- 135 NMR. As seen in table 3 , the pre-run DEPT-135 NMR had atom 1 with a  positive peak   that was part of the CH3 group and atom 2 and 3 with a negative peak that was part of the CH2 group. The negative peaks shown indicated that it is part of the CH2 group while the positive peak indicated it is part of the CH3 group. ConclusionThe  purpose of this experiment was to learn  how 1H and 13C NMR spectroscopy can be used to recognize the structure of organic compounds. We were taught how to use  a benchtop 42.5 MHz Spinsolve Carbon NMR Spectrometer (Magritek)  to identify the unknown alcohol sample that were provided  to us. To conclude, the observed peaks for the unknown alcohol sample that was provided to me was close to that of the predicted peaks for propanol and that  proved that