Chapter 16.5, Problem 10CC

 (a)

Interpretation Introduction

Interpretation: The expected chemical shift values for the given compounds to be identified.

Concept Introduction:

Chemical shift: The frequency of absorption of protons from the reference proton which depends on the various factors like inductive effect, anisotropic effect, diamagnetic effect etc...

Inductive effect: Generally, an electronegative atom pulls the electron density from its neighbor atoms causing the less electron cloud around those atoms is known as inductive effect and those atoms experience the strong external magnetic field; the resonance (energy) gap between spin states increases which absorbs the higher radio frequency and gets shift in order to the reference proton.

Anisotropic effect: The chemical shift of protons affected by the motion of nearby $\text{π-}\text{electrons}$ which characterized by the external magnetic field. The motion of nearby $\text{π-}\text{electrons}$ generates an induced magnetic field that affects the chemical shift value of subjected protons.

Chemical shift values for protons in different electronic environment

Types of protons	Chemical shift
Methyl	$\text{~0}\text{.9}$
methylene	$\text{~1}\text{.2}$
Methine	$\text{~1}\text{.7}$
Allylic	$\text{~2}$
Alkynyl	$\text{~2}\text{.5}$
Aromatic methyl	$\text{~2-5}$
Alkyl halide	$\text{~2-4}$

Alcohol	$~2-5$
Vinyl	$~4.5-6.5$

Aryl	$~6.5-8$
Aldehyde	$~10$
carboxylic	$~12$

 (b)

Interpretation Introduction

Interpretation: The expected chemical shift values for the given compounds to be identified.

Concept Introduction:

Chemical shift: The frequency of absorption of protons from the reference proton which depends on the various factors like inductive effect, anisotropic effect, diamagnetic effect etc...

Inductive effect: Generally, an electronegative atom pulls the electron density from its neighbor atoms causing the less electron cloud around those atoms is known as inductive effect and those atoms experience the strong external magnetic field; the resonance (energy) gap between spin states increases which absorbs the higher radio frequency and gets shift in order to the reference proton.

Anisotropic effect: The chemical shift of protons affected by the motion of nearby $\text{π-}\text{electrons}$ which characterized by the external magnetic field. The motion of nearby $\text{π-}\text{electrons}$ generates an induced magnetic field that affects the chemical shift value of subjected protons.

Chemical shift values for protons in different electronic environment

Types of protons	Chemical shift
Methyl	$\text{~0}\text{.9}$
methylene	$\text{~1}\text{.2}$
Methine	$\text{~1}\text{.7}$
Allylic	$\text{~2}$
Alkynyl	$\text{~2}\text{.5}$
Aromatic methyl	$\text{~2-5}$
Alkyl halide	$\text{~2-4}$

Alcohol	$~2-5$
Vinyl	$~4.5-6.5$

Aryl	$~6.5-8$
Aldehyde	$~10$
carboxylic	$~12$

 (c)

Interpretation Introduction

Interpretation: The expected chemical shift values for the given compounds to be identified.

Concept Introduction:

Chemical shift: The frequency of absorption of protons from the reference proton which depends on the various factors like inductive effect, anisotropic effect, diamagnetic effect etc...

Inductive effect: Generally, an electronegative atom pulls the electron density from its neighbor atoms causing the less electron cloud around those atoms is known as inductive effect and those atoms experience the strong external magnetic field; the resonance (energy) gap between spin states increases which absorbs the higher radio frequency and gets shift in order to the reference proton.

Anisotropic effect: The chemical shift of protons affected by the motion of nearby $\text{π-}\text{electrons}$ which characterized by the external magnetic field. The motion of nearby $\text{π-}\text{electrons}$ generates an induced magnetic field that affects the chemical shift value of subjected protons.

Chemical shift values for protons in different electronic environment

Types of protons	Chemical shift
Methyl	$\text{~0}\text{.9}$
methylene	$\text{~1}\text{.2}$
Methine	$\text{~1}\text{.7}$
Allylic	$\text{~2}$
Alkynyl	$\text{~2}\text{.5}$
Aromatic methyl	$\text{~2-5}$
Alkyl halide	$\text{~2-4}$

Alcohol	$~2-5$
Vinyl	$~4.5-6.5$

Aryl	$~6.5-8$
Aldehyde	$~10$
carboxylic	$~12$

 (d)

Interpretation Introduction

Interpretation: The expected chemical shift values for the given compounds to be identified.

Concept Introduction:

Chemical shift: The frequency of absorption of protons from the reference proton which depends on the various factors like inductive effect, anisotropic effect, diamagnetic effect etc...

Inductive effect: Generally, an electronegative atom pulls the electron density from its neighbor atoms causing the less electron cloud around those atoms is known as inductive effect and those atoms experience the strong external magnetic field; the resonance (energy) gap between spin states increases which absorbs the higher radio frequency and gets shift in order to the reference proton.

Anisotropic effect: The chemical shift of protons affected by the motion of nearby $\text{π-}\text{electrons}$ which characterized by the external magnetic field. The motion of nearby $\text{π-}\text{electrons}$ generates an induced magnetic field that affects the chemical shift value of subjected protons.

Chemical shift values for protons in different electronic environment

Types of protons	Chemical shift
Methyl	$\text{~0}\text{.9}$
methylene	$\text{~1}\text{.2}$
Methine	$\text{~1}\text{.7}$
Allylic	$\text{~2}$
Alkynyl	$\text{~2}\text{.5}$
Aromatic methyl	$\text{~2-5}$
Alkyl halide	$\text{~2-4}$

Alcohol	$~2-5$
Vinyl	$~4.5-6.5$

Aryl	$~6.5-8$
Aldehyde	$~10$
carboxylic	$~12$