Question

Interpret and label each signal in the below C NMR of [Mo(CO)₃(C₇H₈)]   

(CO) 101 MHz. CDCI HO 201.15 40 131.09 120.93 69 921 20 -102.82 -97.27 77.48 CDCI3 -77.17 CDCI3 76.85 CDCI3 -60.25 -27.39 C{H} NMR Spectrum of [Mo (CO) 3 (C7Hg)] (CDCI 3, 101 MHz)

Answer 1

The peak at ~201 ppm corresponds to the carbon atoms of the Carbonyl ligands (CO).

The peak at ~131 and ~127 ppm correspond to para carbons (C-4 and C-5 of tropylium ring).

The peaks at ~121 and ~103 ppm correspond to the meta carbons (C-3 and C-6 of tropylium ring).

The peak at ~97 and ~60 ppm correspond to the ortho carbons (C-2 and C-7 of tropylium ring).

The peak at ~27 ppm corresponds to the ipso carbon(C-1 of tropylium ring).