(a)
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).
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
Bench mark values: The chemical shift values to remember for the protons below.
Methyl |
|
Methylene |
|
Methine |
|
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 |
|
|
Oxygen of ester |
|
|
Carbonyl groups |
|
|
(b)
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).
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
Bench mark values: The chemical shift values to remember for the protons below.
Methyl |
|
Methylene |
|
Methine |
|
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 |
|
|
Oxygen of ester |
|
|
Carbonyl groups |
|
|
(c)
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).
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
Bench mark values: The chemical shift values to remember for the protons below.
Methyl |
|
Methylene |
|
Methine |
|
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 |
|
|
Oxygen of ester |
|
|
Carbonyl groups |
|
|
(d)
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).
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
Bench mark values: The chemical shift values to remember for the protons below.
Methyl |
|
Methylene |
|
Methine |
|
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 |
|
|
Oxygen of ester |
|
|
Carbonyl groups |
|
|
(e)
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).
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
Bench mark values: The chemical shift values to remember for the protons below.
Methyl |
|
Methylene |
|
Methine |
|
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 |
|
|
Oxygen of ester |
|
|
Carbonyl groups |
|
|
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