In estrification lab, the ester was Methyl Benzoate,
((lap report of estrification (methyl Benzoate) NMR spectroscopy )
Q\ Analyze the Peaks of H-NMR spectroscopy
indicating the number of different hydrogen atoms and their
surroundings in the molecule.
Use the table below to fill out the details from the NMR spectroscopy figure .
this is a post lap of Methyl Benzoate
Interpreting Your NMR Spectrum 1. Read the chemical shift of each signal directly from the NMR spectrum by looking at the numbers at the top of the peaks. If the signal is not a singlet, then choose the number from a middle peak 2. To find the number of protons represented by each signal, use the integration numbers that appear below the baseline. You must calculate the ratio of these numbers to get the ratio of numbers of hydrogens represented by each signal 3. Fill in the "splitting" column by looking at each signal and deciding if it is a singlet, doublet, triplet, quartet, or multiplet. You can calculate the J value for a coupling constant by subtracting the chemical shift of one peak from the chemical shift of another peak within the same signal and multiplying by 80, since these spectra were taken on a 80 MHz NMR The J value may be helpful in assigning NMR signals to specific protons 4. To fill in the "assignment" column, assign each signal in the NMR to a set of chemically equivalent protons on your labeled structure. The proton(s) you assign should make sense Esterification, IR, and NMR CHEM 344 Modern Organic Chemistry Laboratory for each of the column headings: the chemical shift will be affected by heteroatoms or aromatic rings near the proton; the integration should match the correct number of equivalent protons for the assignment you are making; the splitting pattern may not be clear, but protons on neighboring carbons generally give reliable splitting patterns (protons on oxygen or nitrogen might not split your assigned proton). You may also need to consider whether you have two overlapping signals: if you have identified four different types of hydrogens, but only see three signals, two signals may be overlapping. The integrations should help you determine if that is the case H NMR Analysis Table: draw the structure with labeled protons in the lab report Coupling Constant (J-value) Assignment ChemicalIntegration Splitting Shift (ppm)
