NMR Lab B Spectroscopy II 1 H NMR 13C NMR and IR Spectroscopy Guidelines and Tips 5 1 6 When labeling peaks don t mistake residual solvent peaks or the TMS peak for a signal peak from the sample 1 H NMR singlet at 7 26 ppm due to residual CHCl3 from CDCl3 solvent singlet at 0 ppm due to TMS 13 C NMR three peaks of equal intensity at 77 16 ppm due to CDCl3 solvent singlet at 0 ppm due to TMS 3 Chemical shifts should be reported as the center of the peak set For peaks with odd multiplicities triplet quintet etc the chemical shift is that of the middle peak For peaks with even multiplicities doublet quartet etc the chemical shift is reported as the average of the two central most peaks 4 The peak labels in the expanded regions are in hertz Hz for assigning coupling constants a The coupling constant J for a given multiplet is equal to the distance in Hz between adjacent peaks 5 Integral values are proportional to the number of hydrogens represented by a given peak 6 Use the following abbreviations for peak multiplicities For our purposes a multiplet m is a peak that cannot be assigned a simple first order splitting pattern i e not a singlet doublet triplet etc singlet s quartet q septet sept doublet d quintet quint octet oct triplet t sextet sext nonet non multiplet m 7 A broad singlet results from a hydrogen attached to an electronegative atom OH NH2 etc 8 Hydrogens on electronegative atoms OH NH2 etc often show no coupling to neighboring hydrogens 9 IR frequencies should be reported in reciprocal centimeters cm 1 H NMR peaks should be labeled using letters a b c etc starting with the peak that is the most downfield highest ppm 13C NMR peaks should be labeled using numbers 1 2 3 etc starting with the peak that is most down eld highest ppm 10 Work your way through the following problems and record your answers in the answer pack When solving the unknowns remember to be systematic and use the data to assemble molecular fragments Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 5 13 C NMR IR Page 7 1 H NMR Page 8 6 13 C NMR IR Page 9 1 H NMR Page 10 7 13 C NMR IR Page 11 1 H NMR Page 12 8 13 C NMR IR Page 13 1 H NMR Page 14 9 13 C NMR IR Page 15 1 H NMR Page 16 10 Complete the spectroscopy data tables in the answer pack using the molecular formula for this compound is C5H9N 13 C NMR IR and 1H NMR spectra shown below The 13 C NMR IR Page 17 1 H NMR Page 18 11 Complete the spectroscopy data tables in the answer pack using the molecular formula for this compound is C5H11NO 13 C NMR IR and 1H NMR spectra shown below The 13 C NMR IR Page 19 1 H NMR Page 20 12 Complete the spectroscopy data tables in the answer pack using the molecular formula for this compound is C6H11ClO 13 C NMR IR and 1H NMR spectra shown below The 13 C NMR IR Page 21 1 H NMR Page 22 Page 23 Page 24 Page 25