i need help with these nmr questions .. Exercise N.5: Spectral Identification Using 'H and 1SC NMR Predict the structure of the organic compounds that give the ill and labeled 5-A through 5-C NMR spectra Problem 5-A δ1.0(3H) δ1,5 (2H) 81.7 (2H) 84.4 (2H) 87.4-8.1 (SH) TMS 'H NMR 85 В.0 75.70 6.5 ea ss so 45 40 36,30,25 20 ia e' as on CDCl TMS 20 10 SoURCE: Reprinted with permission of Aldrich Chemical. 25 20 5 10 CDCH 5. Questions Are the efic emical shifts ofattached electronegative atoms additive fene hete acec acid and methanol using 'H NMR 6. Explain 8. 3Esa pens o acs o singles inthe CW H NMR 4. How could H NMR spectroscopy be used to differentiate between methyl propanate Technique N Nleur Magnetic Resonance Spectroscopyy Problem 5-C CH O 82.2 (3H) 65,9-6.3 (3H) TMS 0.5 HNMR 5 6 045 403 3.5 3.0 25 2.0 15 1.0 05 00 CDCl TMS 1SC NMR 20 10 180 10 10 140 130 120 10 1o0s0 80 0 50 So o20 10 6 SoURCE: Reprinted with permission of Aldrich Chemical. 5. The 'H NMR spectrum of cyclohexane shows one singlet. If the sample is cooled to-80°C, the spectrum changes. Predict the spectrum of the cooled cyclohexane and explain why the spectrum changes as the solution is cooled. What is the purpose of TMS? Predict the chemical shift of the protons in methyllithium (CH;Li). 6. 7. 8. A specific proton in an organic compound has a chemical shift of 63.4 in a 60 MHz NMR spectrum. What will be the chemical shift if the spectrum is recorded using a 90 MHz NMR instrument? The coupling between two protons in an alkene is 10.8 Hz at 60 MHz. What will be the value of the coupling constant between these same two protons at 200 MHz? 9. .. Exercise N.5: Spectral Identification Using 'H and 1SC NMR Predict the structure of the organic compounds that give the ill and labeled 5-A through 5-C NMR spectra Problem 5-A δ1.0(3H) δ1,5 (2H) 81.7 (2H) 84.4 (2H) 87.4-8.1 (SH) TMS 'H NMR 85 В.0 75.70 6.5 ea ss so 45 40 36,30,25 20 ia e' as on CDCl TMS 20 10 SoURCE: Reprinted with permission of Aldrich Chemical. 25 20 5 10 CDCH 5. Questions Are the efic emical shifts ofattached electronegative atoms additive fene hete acec acid and methanol using 'H NMR 6. Explain 8. 3Esa pens o acs o singles inthe CW H NMR 4. How could H NMR spectroscopy be used to differentiate between methyl propanate Technique N Nleur Magnetic Resonance Spectroscopyy Problem 5-C CH O 82.2 (3H) 65,9-6.3 (3H) TMS 0.5 HNMR 5 6 045 403 3.5 3.0 25 2.0 15 1.0 05 00 CDCl TMS 1SC NMR 20 10 180 10 10 140 130 120 10 1o0s0 80 0 50 So o20 10 6 SoURCE: Reprinted with permission of Aldrich Chemical. 5. The 'H NMR spectrum of cyclohexane shows one singlet. If the sample is cooled to-80°C, the spectrum changes. Predict the spectrum of the cooled cyclohexane and explain why the spectrum changes as the solution is cooled. What is the purpose of TMS? Predict the chemical shift of the protons in methyllithium (CH;Li). 6. 7. 8. A specific proton in an organic compound has a chemical shift of 63.4 in a 60 MHz NMR spectrum. What will be the chemical shift if the spectrum is recorded using a 90 MHz NMR instrument? The coupling between two protons in an alkene is 10.8 Hz at 60 MHz. What will be the value of the coupling constant between these same two protons at 200 MHz? 9.