Chapter 15.5, Problem 8PTS

(a)

Interpretation Introduction

Interpretation: For the given compounds the chemical shift of the signal to be predicted.

Concept Introduction:

Chemical shift: The frequency of the proton signal in the spectrum with reference to the standard compound  which may be TMS(Tetramethylsilane) shows signal at 0 ppm(parts per million).

$\text{Chemical}\text{shift}\text{=}\frac{\text{signal}\text{frequency-}\text{reference}\text{frequency}}{\text{frequency}\text{of}\text{spectrometer}}\left({\text{10}}^{\text{6}}\right)$

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.

Bench mark values: The chemical shift values to remember for the protons below.

Methyl	$\text{0}\text{.9}$ (chemical shift)
Methylene	$\text{1}\text{.2}$ (chemical shift)
Methine	$\text{1}\text{.7}$ (chemical shift)

Inductive effect: The presence of functional groups at the alpha position has impact on the protons

FUNCTIONAL GROUP	EFFECT ON THE ALPHA PROTONS	EFFECT ON THE BETA PROTONS
Oxygen of an alcohol or ether	$\text{+2}\text{.5}$	$\text{+0}\text{.5}$
Oxygen of ester	$\text{+3}\text{.0}$	$\text{+0}\text{.6}$
Carbonyl groups	$\text{+1}\text{.0}$	$\text{+0}\text{.2}$

 (b)

Interpretation Introduction

Interpretation: For the given compounds the chemical shift of the signal to be predicted.

Concept Introduction:

Chemical shift: The frequency of the proton signal in the spectrum with reference to the standard compound  which may be TMS(Tetramethylsilane) shows signal at 0 ppm(parts per million).

$\text{Chemical}\text{shift}\text{=}\frac{\text{signal}\text{frequency-}\text{reference}\text{frequency}}{\text{frequency}\text{of}\text{spectrometer}}\left({\text{10}}^{\text{6}}\right)$

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.

Bench mark values: The chemical shift values to remember for the protons below.

Methyl	$\text{0}\text{.9}$ (chemical shift)
Methylene	$\text{1}\text{.2}$ (chemical shift)
Methine	$\text{1}\text{.7}$ (chemical shift)

Inductive effect: The presence of functional groups at the alpha position has impact on the protons

FUNCTIONAL GROUP	EFFECT ON THE ALPHA PROTONS	EFFECT ON THE BETA PROTONS
Oxygen of an alcohol or ether	$\text{+2}\text{.5}$	$\text{+0}\text{.5}$
Oxygen of ester	$\text{+3}\text{.0}$	$\text{+0}\text{.6}$
Carbonyl groups	$\text{+1}\text{.0}$	$\text{+0}\text{.2}$

(c)

Interpretation Introduction

Interpretation: For the given compounds the chemical shift of the signal to be predicted.

Concept Introduction:

Chemical shift: The frequency of the proton signal in the spectrum with reference to the standard compound  which may be TMS(Tetramethylsilane) shows signal at 0 ppm(parts per million).

$\text{Chemical}\text{shift}\text{=}\frac{\text{signal}\text{frequency-}\text{reference}\text{frequency}}{\text{frequency}\text{of}\text{spectrometer}}\left({\text{10}}^{\text{6}}\right)$

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.

Bench mark values: The chemical shift values to remember for the protons below.

Methyl	$\text{0}\text{.9}$ (chemical shift)
Methylene	$\text{1}\text{.2}$ (chemical shift)
Methine	$\text{1}\text{.7}$ (chemical shift)

Inductive effect: The presence of functional groups at the alpha position has impact on the protons

FUNCTIONAL GROUP	EFFECT ON THE ALPHA PROTONS	EFFECT ON THE BETA PROTONS
Oxygen of an alcohol or ether	$\text{+2}\text{.5}$	$\text{+0}\text{.5}$
Oxygen of ester	$\text{+3}\text{.0}$	$\text{+0}\text{.6}$
Carbonyl groups	$\text{+1}\text{.0}$	$\text{+0}\text{.2}$

(d)

Interpretation Introduction

Interpretation: For the given compounds the chemical shift of the signal to be predicted.

Concept Introduction:

Chemical shift: The frequency of the proton signal in the spectrum with reference to the standard compound  which may be TMS(Tetramethylsilane) shows signal at 0 ppm(parts per million).

$\text{Chemical}\text{shift}\text{=}\frac{\text{signal}\text{frequency-}\text{reference}\text{frequency}}{\text{frequency}\text{of}\text{spectrometer}}\left({\text{10}}^{\text{6}}\right)$

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.

Bench mark values: The chemical shift values to remember for the protons below.

Methyl	$\text{0}\text{.9}$ (chemical shift)
Methylene	$\text{1}\text{.2}$ (chemical shift)
Methine	$\text{1}\text{.7}$ (chemical shift)

Inductive effect: The presence of functional groups at the alpha position has impact on the protons

FUNCTIONAL GROUP	EFFECT ON THE ALPHA PROTONS	EFFECT ON THE BETA PROTONS
Oxygen of an alcohol or ether	$\text{+2}\text{.5}$	$\text{+0}\text{.5}$
Oxygen of ester	$\text{+3}\text{.0}$	$\text{+0}\text{.6}$
Carbonyl groups	$\text{+1}\text{.0}$	$\text{+0}\text{.2}$

 (e)

Interpretation Introduction

Interpretation: For the given compounds the chemical shift of the signal to be predicted.

Concept Introduction:

Chemical shift: The frequency of the proton signal in the spectrum with reference to the standard compound  which may be TMS(Tetramethylsilane) shows signal at 0 ppm(parts per million).

$\text{Chemical}\text{shift}\text{=}\frac{\text{signal}\text{frequency-}\text{reference}\text{frequency}}{\text{frequency}\text{of}\text{spectrometer}}\left({\text{10}}^{\text{6}}\right)$

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.

Bench mark values: The chemical shift values to remember for the protons below.

Methyl	$\text{0}\text{.9}$ (chemical shift)
Methylene	$\text{1}\text{.2}$ (chemical shift)
Methine	$\text{1}\text{.7}$ (chemical shift)

Inductive effect: The presence of functional groups at the alpha position has impact on the protons

FUNCTIONAL GROUP	EFFECT ON THE ALPHA PROTONS	EFFECT ON THE BETA PROTONS
Oxygen of an alcohol or ether	$\text{+2}\text{.5}$	$\text{+0}\text{.5}$
Oxygen of ester	$\text{+3}\text{.0}$	$\text{+0}\text{.6}$
Carbonyl groups	$\text{+1}\text{.0}$	$\text{+0}\text{.2}$