Question

Use ir and nmr to identify functional groups and ir stretchs, draw out structure and calculate degrees of unsaturation.

Question 9: CH,02 WWW 80 TRANSMITTANCE [%] 60 40 20 4000 3500 3000 1500 1000 2500 2000 WAVENUMBER (cm.) 500

Answer 1

IR Spectrum Analysis The stretch band at = 3080 cm can be assigned to the C(sp')-H (Aromatic). The stretch band at -31680 cm can be assigned to the CEO of esthe. C,H,O2 Degrees of unsaturation=HDI = (10x2+2)-8/2 = 7 Number of unsaturations = 7 Attributed to: C=0, Attributed to: C=0, and and = Two insaturations One insaturations One insaturations Four insaturations Four insaturations 1H NMR Spectrum Analysis 8 (ppm): 2.60 (s, 3H, CH) 7.30 (m, 1H, H-Ar) 7.47 (m, 2H, H-Ar) 7.57 (dd, 1H, H-Ar) 7.67 (dd, 1H, H-Ar) 2-Phenylethynyl acetate So: The most likely structure is CH3