Chapter 14, Problem 35PP

(a)

Interpretation Introduction

Interpretation:

For the given compound, the responsible bonds for absorption and its signal in the diagnostic region of IR spectrum should be identified.

Concept introduction:

IR spectrum can be divided into two main regions,

1. 1. Diagnostic region (wavenumber above 1500 ${\text{cm}}^{\text{-1}}$)
2. 2. Finger print region(wavenumber below 1500 ${\text{cm}}^{\text{-1}}$)

 The diagnostic region consists of signals from the double bonds, triple bonds and the $\text{X}\text{-}\text{H}$ type ( $\text{O-H, C-H or N-H}$) bonds.

Finger print region contains signals from the single bonds only.

Reciprocal of wavelength is called wavenumber or Number of waves in one centimeter is called wavenumber

Unit of wave number is reciprocal of Centimeter.

According to Hooke’s law the factors affecting wave numbers are

1. Bond strength

2. Reduced mass

So, in the diagnostic region on comparing double bonds, triple bonds and the $\text{X}\text{-}\text{H}$ type ( $\text{O-H, C-H or N-H}$) bond on the basis Hooke’s law double bond appears at wave number 1600-1850 $c{m}^{-1}$ and the $\text{X}\text{-}\text{H}$ type bonds appears at the left side of the spectrum (above 2700 $c{m}^{-1}$). Triple bonds appears in between these two bonds(2100-2300 $c{m}^{-1}$)

(b)

Interpretation Introduction

Interpretation:

For the given compound, the responsible bonds for absorption and its signal in the diagnostic region of IR spectrum should be identified.

Concept introduction:

IR spectrum can be divided into two main regions,

1. 3. Diagnostic region (wavenumber above 1500 ${\text{cm}}^{\text{-1}}$)
2. 4. Finger print region(wavenumber below 1500 ${\text{cm}}^{\text{-1}}$)

 The diagnostic region consists of signals from the double bonds, triple bonds and the $\text{X}\text{-}\text{H}$ type ( $\text{O-H, C-H or N-H}$) bonds.

Finger print region contains signals from the single bonds only.

Reciprocal of wavelength is called wavenumber or Number of waves in one centimeter is called wavenumber

Unit of wave number is reciprocal of Centimeter.

According to Hooke’s law the factors affecting wave numbers are

1. Bond strength

2. Reduced mass

So, in the diagnostic region on comparing double bonds, triple bonds and the $\text{X}\text{-}\text{H}$ type ( $\text{O-H, C-H or N-H}$) bond on the basis Hooke’s law double bond appears at wave number 1600-1850 $c{m}^{-1}$ and the $\text{X}\text{-}\text{H}$ type bonds appears at the left side of the spectrum (above 2700 $c{m}^{-1}$). Triple bonds appears in between these two bonds(2100-2300 $c{m}^{-1}$)

(c)

Interpretation Introduction

Interpretation:

For the given compound, the responsible bonds for absorption and its signal in the diagnostic region of IR spectrum should be identified.

Concept introduction:

IR spectrum can be divided into two main regions,

1. 5. Diagnostic region (wavenumber above 1500 ${\text{cm}}^{\text{-1}}$)
2. 6. Finger print region(wavenumber below 1500 ${\text{cm}}^{\text{-1}}$)

 The diagnostic region consists of signals from the double bonds, triple bonds and the $\text{X}\text{-}\text{H}$ type ( $\text{O-H, C-H or N-H}$) bonds.

Finger print region contains signals from the single bonds only.

Reciprocal of wavelength is called wavenumber or Number of waves in one centimeter is called wavenumber

Unit of wave number is reciprocal of Centimeter.

According to Hooke’s law the factors affecting wave numbers are

1. Bond strength

2. Reduced mass

So, in the diagnostic region on comparing double bonds, triple bonds and the $\text{X}\text{-}\text{H}$ type ( $\text{O-H, C-H or N-H}$) bond on the basis Hooke’s law double bond appears at wave number 1600-1850 $c{m}^{-1}$ and the $\text{X}\text{-}\text{H}$ type bonds appears at the left side of the spectrum (above 2700 $c{m}^{-1}$). Triple bonds appears in between these two bonds(2100-2300 $c{m}^{-1}$)

(d)

Interpretation Introduction

Interpretation:

For the given compound, the responsible bonds for absorption and its signal in the diagnostic region of IR spectrum should be identified.

Concept introduction:

IR spectrum can be divided into two main regions,

1. 7. Diagnostic region (wavenumber above 1500 ${\text{cm}}^{\text{-1}}$)
2. 8. Finger print region(wavenumber below 1500 ${\text{cm}}^{\text{-1}}$)

 The diagnostic region consists of signals from the double bonds, triple bonds and the $\text{X}\text{-}\text{H}$ type ( $\text{O-H, C-H or N-H}$) bonds.

Finger print region contains signals from the single bonds only.

Reciprocal of wavelength is called wavenumber or Number of waves in one centimeter is called wavenumber

Unit of wave number is reciprocal of Centimeter.

According to Hooke’s law the factors affecting wave numbers are

1. Bond strength

2. Reduced mass

So, in the diagnostic region on comparing double bonds, triple bonds and the $\text{X}\text{-}\text{H}$ type ( $\text{O-H, C-H or N-H}$) bond on the basis Hooke’s law double bond appears at wave number 1600-1850 $c{m}^{-1}$ and the $\text{X}\text{-}\text{H}$ type bonds appears at the left side of the spectrum (above 2700 $c{m}^{-1}$). Triple bonds appears in between these two bonds(2100-2300 $c{m}^{-1}$)