Skip to main content
Chemistry LibreTexts

5.6: More Practice with 2D

  • Page ID
    189780
  • The following problems involve real samples. Note that you may need to check for peaks due to solvent. Helpful tables may be found here.

    Exercise \(\PageIndex{1}\)

    The following problems involve real samples. Note that you may need to check for peaks due to solvent. Helpful tables may be found here.

    clipboard_ec0078d77b5d67bc717a28d1fced6c662.png

    Note that the m beside one of the integral values stands for milli (one thousandth). 61.29m = 0.06129 units.

    An expansion of the 1H NMR spectrum:

    clipboard_e7781ce3359d1e6c190cdb5e3e03da5ba.png

    Another expansion:

    clipboard_e7f1a8deddaf5dc21aa48917a7badc54b.png

    A 13C NMR spectrum:

    clipboard_eb99be834c3bcbe73817ad3164c22ef33.png

    COSY spectrum:

    clipboard_e55c3e3b0a4a2c67c78b0f3ae5315ec1f.png

    HMQC spectrum:

    clipboard_e1ce19af094b007d9d9c7a1b7622c55c2.png

    HMBC spectrum:

    clipboard_eca55b2bfe172ee2b9711188658e07702.png

    Answer

    1H NMR

    Chemical shift (ppm) Integration Multiplicity Partial Structure
    5.54 2H multiplet CH=C (x 2)
    4.17 2H doublet O-CH2-CH
    2.08 2H quintet CH-CH2-CH3
    1.47 1H boad singlet OH
    0.95 3H triplet CH2-CH3

    * total # H: 10

    13C NMR

    Chemical shift (ppm)

    Type of carbon
    134 sp2
    128

    sp2

    58 sp3-O
    21 sp3
    14 sp3

    *total # C: 5

    COSY

    Assignment 1H COSY
    A 0.95 2.08
    B 2.08 0.95, 5.54
    C 4.17 5.54
    D 5.54 2.08
    E 5.54 4.17

    *HMQC indicates two hydrogens at 5.54 are in two different environments

    HMQC

    Assignment 13C 1H
    A 14 0.95
    B 21 2.08
    C 58 4.17
    D 128 5.54
    E 134 5.54

    Formula:

    C5H10O (1 O indicated from shift in 13C, 1H NMR)

    FW = \(5 \times 12) + (10 \times 1) + (1 \times 16) = 86\)

    Compare C5H10 ratio to C5H12 in hydrocarbon

    Degrees of unsaturation = \(\frac{(2 \times 5) + 2 - 10}{2} = 1 unit (1 double bond)

    The data tables should be consitent with this structure:

    pent-2-en-1-ol (could be cis or trans based on this analysis)

    Exercise \(\PageIndex{2}\)

    Present an analysis of the following data and propose a structure.

    MW: 202 amu

    The full 1H NMR spectrum in D2O:

    clipboard_ef023c39bc18785c0591f25e6649d8c0d.png

    An expansion:

    clipboard_e2d38ec70a1e2bc2d8ff85f1349c8b7ad.png

    13C NMR:

    clipboard_e0ae5a78b51babb8a3383482ff2829528.png

    COSY:

    clipboard_e4d70242ff5b204a0d8476a39f2bd0225.png

    Answer

    1H NMR:

    Chemical shift (ppm) Integration Multiplicity Partial structure
    4.7 5H singlet solvent
    3.93 1H triplet CH2-CH-N
    2.40 2H multiplet CH2-CH2?
    2.09 2H multiplet CH2-CH2?
    1.4 9H singlet C(CH3)3

    *Total number of H: 19 H

    13C NMR:

    Chemical shift (ppm) Type of carbon
    170 sp2 (C=O)
    80 sp3 (C-O)
    52 sp3 (C-N)
    32 sp3
    28 sp3
    26 sp3

    *Total number of C: 6 apparent, but two more suggested by symmetry (3 methyl groups in 1H NMR) for 8 C; a third extra suggested by MW fit for 9 C

    COSY:

    Assignment 1H COSY
    Solvent 4.7 --
    B 3.93 2.40
    D 2.40 2.09
    C 2.09 2.40, 2.09
    A 1.4 --

    Formula:

    C9H18O3N2 (extra O indicated from shift in 13C, 1H NMR; second O suggested by C=O in 13C NMR; additional CO needed to fit MW)

    FW = \((9 \times 12) + (18 \times 1) + (3 \times 16) + (2 \times 14) = 202\)

    FW = ((9 \times 12) + (18 \times 1) + (3 \times 16) + (2 \times 14) = 202\)

    Compare C9H18 to C9H22 for the corresponding hydrocarbon corrected for two nitrogens (therefore two extra hydrogens)

    Degrees of unsaturation = \(\frac{(2 \times 9) + 2 + 2 - 10}{2} = 2\) units (2 double bonds)

    The data tables should be consistent with this structure:

    clipboard_ead408645f2f062bc2fa72c1030ec8294.png

    Exercise \(\PageIndex{3}\)

    Present an analysis of the following data and propose a structure.

    MW: 164 amu

    The full 1H NMR spectrum in CDCl3:

    clipboard_e9c61757c468cf0676f12edf2514e4efa.png

    An expansion of the 1H NMR spectrum:

    clipboard_ecdbf3d556abe0a6e8830db1e7bc9a686.png

    Another expansion:

    clipboard_e8b63e87d7e59de6b4c13b33401e7cd91.png

    13C NMR spectrum:

    clipboard_e9b416e8be544a74d7b1c2d4a7f9a573a.png

    COSY spectrum:

    clipboard_e00831f53ea6371f403c36018591cebe0.png

    HMQC:

    clipboard_e82d4a921b6d912f73c2919bd26482ae3.png

    HMBC:

    clipboard_eabdbb9cb6ad1a3b587e512f6cb74e330.png

    Answer

    The data should be consistent with this structure:

    clipboard_ece9c5ea821dd696fe8402a6b611a9260.png

    Exercise \(\PageIndex{4}\)

    Present an analysis of the following data and propose a structure.

    MW: 131 amu

    The full 1H NMR spectrum in D2O:

    clipboard_e47c15dd67549ac70c3aea75b7c56e74c.png

    An expansion:

    clipboard_e9a98305806cf3039706556bf74231636.png

    13C NMR:

    clipboard_eda7101a649585ad50d0130093be7ab13.png

    COSY:

    clipboard_ecdd83bbb696f39bc8d0e180c7204d88b.png

    HMBC:

    clipboard_e20541ddb4c21f59a3fc03486b8945697.png

    Answer

    1H NMR:

    Chemical shift (ppm)

    Integration Multiplicity Partial Structure
    4.71 -- singlet solvent
    4.17 1H doublet? CO-CH-N
    3.75 3H singlet O-CH3
    2.25 1H multiplet CH-CH-(CH3)2
    0.92 6H triplet? 2 x CH3

    13C NMR:

    Chemical shift (ppm) Type of carbon
    170 sp2 C=O
    60 sp3 C-N
    52 sp3 C-O
    30 sp3 C
    19 sp3 C

    COSY:

    Assignment 1H COSY
    A 4.17 2.25
    B 3.75 --
    C 2.25 4.17
    D 0.92 2.25

    Formula:

    C6H13O2N (1 O indicated from shift in 13C, 1H NMR)

    FW = \((6 \times 120 + (13 \times 1) + (2 \times 16) + (1 \times 14) = 131\)

    Degrees of unsaturation = \(\frac{(2 \times 6) + 2 + 1 - 13}{2} = 1\) unit (1 double bond)

    The data should be consistent with this structure:

    clipboard_ed8329eeae8d4515423ef3e4828369129.png

    Exercise \(\PageIndex{5}\)

    Present an analysis of the following data and propose a structure.

    MW: 144 amu

    The 1H NMR spectrum in CDCl3:

    clipboard_e3c4eab591c88f6459615a3371c85bc3c.png

    An expansion of the 1H NMR spectrum:

    clipboard_ea5785d84eba91866a6f0facd919167a1.png

    13C NMR spectrum:

    clipboard_e3b25ca35b2983bdac1a9ec203e0f27bf.png

    COSY:

    clipboard_e10f00f1b0a47bbe803c8ef196314e949.png

    An expansion of the COSY spectrum:

    clipboard_ee50ff43b432de5ab250b7fe08e84cb80.png

    HMBC:

    clipboard_ec6d3945dc1266a9656b667f60683055b.png

    An expansion of the HMBC spectrum:

    clipboard_ec50c8fa9dcd78077d9bcc2cda0ec5390.png

    Answer

    clipboard_e94eb1b86f7320e2ed8c8b25b77b559fe.png

    Exercise \(\PageIndex{6}\)

    Present an analysis of the following data and propose a structure.

    MW: 164 amu

    The full 1H NMR spectrum in CDCl3:

    clipboard_e847b7c63b459fc023a9ad1eb6f4780a8.png

    AN expansion:

    clipboard_e858bc72494be6a0f6051dc3958a8f896.png

    13C NMR:

    clipboard_e64a173c31944545cf037962f0020af1e.png

    COSY:

    clipboard_e0b6eea1a8c24854a5234a4783a405af5.png

    Expansion of COSY spectrum:

    clipboard_eb8b085b0f6bdf04d579fdec656040234.png

    Answer

    The data should be consistent with this structure:

    clipboard_e61a6b7aa2d4738f631bde31840f44066.png

    Exercise \(\PageIndex{7}\)

    Present an analysis of the following data and propose a structure.

    MW: 129 amu

    The full 1H NMR spectrum in D2O:

    clipboard_e00cadcfc9daafeeea1c639b742b42462.png

    13C NMR spectrum:

    clipboard_e3ec02047708929ce2798879eef6b57d3.png

    COSY spectrum:

    clipboard_eddf29d419a8623c1fe4cb34f1ac20785.png

    Answer

    The data should be consistent with this structure:

    clipboard_e5d98b582ca345f3d0767e7b6de1c3297.png

    Exercise \(\PageIndex{8}\)

    Present an analysis of the following data and propose a structure.

    MW: 173 amu

    The full 1H NMR spectrum in CDCl3:

    clipboard_e929b6effb761a507d52506f7a8b8b0e3.png

    An expansion of the 1H NMR spectrum:

    clipboard_eb6bde7515d3c85150ed5d41b84e532f9.png

    13C NMR spectrum:

    clipboard_e2057520797d282258ab3c87d9a94550f.png

    COSY:

    clipboard_eb020d62d1b685293a76a0473a5debca4.png

    HMQC:

    clipboard_e1dd149e8cf99ef916a77312bc4507aa3.png

    HMBC:

    clipboard_e38cc23c39999a22c168aaf6c3020bcca.png

    Answer

    The data should be consistent with this structure:

    clipboard_e2f638d4b318bc1bb740dd38cfe4e09bc.png

    Exercise \(\PageIndex{9}\)

    Present an analysis of the following data and propose a structure.

    MW: 145 amu

    The full 1H NMR spectrum in D2O:

    clipboard_eff9c14002cafc447a37737e81a2e8070.png

    An expanded view of 1H NMR spectrum:

    clipboard_e719a254005b25a797403d99b9b3f7d64.png

    Another expanded view:

    clipboard_ec5cedc3fc609146f8e444f5b8d3df31f.png

    13C NMR spectrum:

    clipboard_e42f72f5916644dd07aaf36163cf29ee9.png

    COSY spectrum:

    clipboard_e4a8799d54ab55246e3ea4b2b2834ede7.png

    Answer

    The data should be consistent with this structure:

    clipboard_e9bfbabdd794d8e1f2095ccbca8ad834c.png

    Exercise \(\PageIndex{10}\)

    Present an analysis of the following data and propose a structure.

    MW: 251 amu

    The full 1H NMR spectrum in DMSO-d6:

    clipboard_e3c83b28c4c6be15eeeb4bf15f2f608f4.png

    An expanded view of the 1H NMR spectrum:

    clipboard_e48b6457b65c384bf0dba0a929b80e27b.png

    Another expansion:

    clipboard_edc0a4e2325885b206b7a9ba666149157.png

    13C NMR spectrum:

    clipboard_e569b18dabaf3ef6d537233e1fa9b10e8.png

    COSY spectrum:

    clipboard_e854be55ab46d24441d2e121293c153bb.png

    Expansion of COSY:

    clipboard_ee47911411fb7377e9235b44e4b382e32.png

    HMQC spectrum:

    clipboard_e5426eeb3d8dd2bc052f04ad99a36b675.png

    Answer

    The data should be consistent with this structure:

    clipboard_ee6134fbc46addb5e4d88525de6b9109f.png

    Exercise \(\PageIndex{11}\)

    Present an analysis of the following data and propose a structure.

    MW: 244 amu

    The full 1H NMR spectrum in DMSO-d6:

    clipboard_e8b0ae6385ae4380acc720d11879d090d.png

    An expanded view of the 1H NMR spectrum:

    clipboard_ececc3516f6dae6e26faf5e442f607a7c.png

    Another expansion of the 1H NMR spectrum:

    clipboard_e998ac929fb318bea5b0ae210a8e11605.png

    13C NMR spectrum:

    clipboard_ecc1eca6f495737b73e8380d3fc94f71f.png

    COSY:

    clipboard_e4a19db2e6e2e7cf565c255ac514b3d17.png

    An expanded view of the COSY spectrum:

    clipboard_e2dd5a658ad426314e17ca7850f2c4ad2.png

    Answer

    The data should be consistent with this structure:

    clipboard_e97eab53cd7a5d4700a2f147ad5418308.png

    Exercise \(\PageIndex{12}\)

    Present an analysis of the following data and propose a structure.

    MW: 242 amu

    The full 1H NMR spectrum in DMSO-d6:

    clipboard_efb9108ae0e7d24cd1a653b8ca4943359.png

    Expansion of the 1H NMR spectrum:

    clipboard_e6e75aa1deee9cb0d8de79053962da708.png

    Another expansion:

    clipboard_e3e2ca5b86a6025134ec662c97e21809c.png

    13C NMR spectrum:

    clipboard_e6d05a02e2f4bb6b2c0ca54179eaab49b.png

    COSY:

    clipboard_e57a1c4948ddf5f0800b6995ebb6e274e.png

    An expansion of the COSY spectrum:

    clipboard_e6fe49dcf2733574c3a10b25e4b2dca3f.png

    Answer

    The data should be consistent with this structure:

    clipboard_ee218fdeeb8b8fb51af16489d140aad2f.png

    Exercise \(\PageIndex{13}\)

    Present an analysis of the following data and propose a structure.

    MW: 152 amu

    The full 1H NMR spectrum in CDCl3:

    clipboard_ebbaaa4e40e75c3793e5b901a96c87ad8.png

    An expansion of the 1H NMR spectrum:

    clipboard_eadaf995b5b1904e471fd413b1935cca8.png

    13C NMR spectrum in CDCl3:

    clipboard_e6dd287e6a25b9a816ba9fa5f7a03a6c7.png

    COSY spectrum:

    clipboard_eb9afd40b9e7bd7aef425f9867b7ad928.png

    HMQC spectrum:

    clipboard_ef3949edd2f55d11278311ccf0ba22869.png

    HMBC spectrum:

    clipboard_e0451ca6ddbad004e1ed273557fde1154.png

    Answer

    1H NMR:

    Chemical shift (ppm) Integration Multiplicity Partial structure
    5.7 1H singlet C=CH-CO
    2.77 1H multiplet CH2-CH-CO
    2.62 1H multiplet C-CH-C
    2.39 1H multiplet C-CH-C
    2.05 1H doublet? C-CH-CH?
    1.96 3H singlet C-CH3
    1.48 3H singlet C-CH3
    0.98 3H singlet C-CH3

    13C NMR:

    Chemical shft (ppm) Type of carbon
    204 sp2 C=O
    170 sp2
    121 sp2
    59 sp3
    55 sp3
    50 sp3
    41 sp3
    28 sp3
    24 sp3
    22 sp3

    COSY:

    Assignment 1H COSY
    1 2.39 2.77, 2.62?
    3 5.7 2.05?
    5 2.62 2.62?
    7a 2.77 2.05
    7b 2.05 2.77
    8 1.48 --
    9 0.98 --
    10 1.96 --

    Formula:

    C10H14O (1 O indicated from shift in 13C, 1H NMR)

    FW = \((10 \times 12) + (14 \times 1) + (1 \times 16) = 150 \)

    Degrees of unsaturation = \(\frac{(2 \times 10) + 2 - 14}{2} = 4 units (e.g. 2 rings, 2 double bonds)

    The data should be consistent with this structure:

    clipboard_ee27a8905599737f54cd81e4f0bed4801.png

    Exercise \(\PageIndex{14}\)

    Present an analysis of the following data and propose a structure.

    MW: 152 amu

    The full 1H NMR spectrum in CDCl3:

    clipboard_ebb6ddb80a435aa2c5dd2759782f6c525.png

    13C NMR spectrum:

    clipboard_edde25650d3eb484c9c603ea3d99b468b.png

    COSY spectrum:

    clipboard_e2c39c77817784c2ef4d6a8fdffa3868f.png

    HMQC spectrum:

    clipboard_e2b0514e3b840e7020fdc40f9ce1970a8.png

    HMBC spectrum:

    clipboard_e8b592dd41433b91b59863c3405a3d107.png

    Answer

    The data should be consistent with this structure:

    clipboard_e458251c20f61c1f7000b2fdfc6c83d93.png

    Exercise \(\PageIndex{15}\)

    Present an analysis of the following data and propose a structure.

    MW: 150 amu

    The full 1H NMR spectrum in CDCl3:

    clipboard_e90760c5a660884bb2f70db13c3d5b035.png

    An expansion of the 1H NMR spectrum:

    clipboard_ebb52b2cee7c39d09cb349fc1a25f67d7.png

    13C NMR spectrum:

    clipboard_e817625939ec557a120ad72c24cf14f13.png

    COSY spectrum:

    clipboard_e7a7e3a17edfc0869a36a45a37765d297.png

    HMQC spectrum:

    clipboard_e9db4fcc79b146afd8386d02e388de4c7.png

    HMBC spectrum:

    clipboard_e8da772d30e4dd34f68adfef94d14ed3b.png

    Answer

    The data should be consistent with this structure:

    clipboard_ef584d1112d799ff07a6f73c068271dde.png

    NMR spectra obtained on a JEOL 400 MHz NMR spectrometer.