Organic Chemistry

481

You have now worked through many

problems that asked you to design the

synthesis of an organic compound. But if

you were actually to go into the laborato-

ry to carry out a synthesis you designed,

how would you know that the compound

you obtained was the one you had set out

to prepare? When a scientist discovers a

new compound with physiological activi-

ty, its structure must be determined. Only

after its structure is known, can methods

to synthesize the compound be designed

and studies to provide insights into its bi-

ological behavior be carried out. Clearly,

chemists need to be able to determine the

structures of compounds.

In Chapters 13 and 14 , you will learn about three
instrumental techniques that chemists use to identify
compounds.

Mass spectrometryis used to determine the molecular
mass and the molecular formula of an organic com-
pound and to identify certain structural features of the
compound.

Infrared (IR) spectroscopyis used to determine the
kinds of functional groups in an organic compound.

Nuclear magnetic resonance (NMR) spectroscopy
helps to identify the carbon–hydrogen framework of an
organic compound.

Identification

of Organic

Compounds

PA R T F O U R

Chapter 13

Mass Spectrometry and Infrared

Spectroscopy

Chapter 14

NMR Spectroscopy