Question

Provide a structure for the compound with molecular formula C9H12 and with the following spectroscopic data.1H NMR: 1.2δ (doublet, I=6H), 3.0δ (septet, I=1H), 7.1δ (multiplet, I=5H)

Answer 1

Answer:

The structure analysis says the compound must be Cumene or isopropylbenzene

Explanation:

Degree of unsaturation or double bond equivalent

         D.B.E     =      $C-\frac{H}{2}+\frac{N}{2}+1$

                       =       $9-\frac{12}{2}+\frac{0}{2}+1$

                       =       4

¹H NMR data analysis

  (i)  1.2δ (doublet, I = 6H)   two CH₃ are equivalents and the multiplicity says the neighboring carbon have one hydrogen.

 (ii)  3.0δ (septet, I = 1H), one CH and the multiplicity says the neighboring carbon  have six hydrogens.

 (iii)  7.1δ (multiplet, I = 5H) , means

and the sturcture of the compound is