Question

Determine the structure using the following spectroscopy (NMR spectrum analysis, chemical shifts, and multiplicity):

MF: CHN CT TH-NMR 2 PPM 1)C-NMR

Answer 1

Degree of Unsaturation (DOU) is also known as Double Bond Equivalent. If the molecular formula is given, DoU can be calculated as follows

DoU   =   2C+2+N−X−H

               2

C is the number of carbons

N is the number of nitrogens

X is the number of halogens (F, Cl, Br, I)

H is the number of hydrogens

Molecular formula = C5H13N

Sites of unsaturation = 0

¹H NMR data:

NMR peak value (ppm)	Multiplicity	Protons	Indication
2.6	Multiplet	1H	Aliphatic proton
2.0	Broad singlet	2H	NH2 present
1.40-1.52	Multiplet	4H	Two equivalent CH2 present
0.9	Triplet	6H	Two equivalent CH3 present attached to CH2

¹³C NMR data:

NMR peak value (ppm)	Multiplicity	Protons	Indication
58	Singlet	Aliphatic carbon	Carbon attached to amine
30	Singlet	Aliphatic carbon	-
12	Singlet	Aliphatic carbon	-

IR data:

IR peak (cm-1)	Indication
2950	Aliphatic C-H stretch
3300-3400 (doublet)	NH2 confirmed

Above data confirms following structure

pentan-3-amine