1. a. Answer the below with reference to the structures shown in Figure 1. (i) Predict the chemical shift position of H4 in the 'H NMR spectra of each of the structures (1) (2) and (3). With the use of appropriate resonance structures account for the trend you propose. [5 marks] (ii) For structure (3) state the expected multiplicity of the H4 proton resonance. Draw, and label a splitting diagram and use it to account for the multiplicity you propose. [4 marks] (iii) Explain how the 'H NMR spectrum of compound (3) recorded in CDC13 plus a few drops of D20 is expected to differ from the spectrum of the same compound recorded in CDC13. Include an equation in your answer. [4 marks] H-CH3 N NO2 NO2 HA HA HA ON (1) (3) (2) Figure 1