Chapter 16, Problem 16.64P

Interpretation Introduction

Interpretation:

Which of the two ${}^{13}\text{C}$ NMR spectra given corresponds to chlorocyclohexane and which corresponds to iodocyclohexane is to be determined.

Concept introduction:

${}^{13}\text{C}$ NMR provides valuable information about the carbon skeleton. Each signal in ${}^{13}\text{C}$ NMR equals the number of distinct carbon atoms in the given unknown. In most of the ${}^{13}\text{C}$ NMR spectra, almost every time, all the signals would appear as singlets. The saturated carbon atoms appear in the range $\text{δ}\text{0-35 ppm}$ if it is a simple alkane fragment. If it is attached to any electronegative element such as halogens or nitrogen, then the range is $\text{δ}\text{25-70 ppm}$. Triple bonded carbon atoms range from $\text{δ}\text{65-85 ppm}$. Alkene carbons range from $\text{δ}\text{105-150 ppm}$. Carbonyl carbon atoms in acids, esters, amides, and anhydrides range from $\text{δ}\text{120-185 ppm}$. Carbonyl carbons in aldehydes and ketones range from $\text{δ}\text{190-220 ppm}$. The carbon bonded to chlorine atom must have chemical shift of $\text{33-55 ppm}$.