Rank the structures in order of decreasing electrophile strength [Solved]

Total: 4 question (Solved)

Question 1

  1. Rank the following structures in order of decreasing electrophile strength
  2. Draw the major organic product formed in the following reaction. (The reaction stoichiometry is 1 mol reactant: 1 mol Br2.)
  3. In each reaction box, place the best reagent and conditions from the list below

Question 2

Rank the following structures in order of decreasing electrophile strength

Question 3

Rank the following structures in order of decreasing electrophile strength

Question 4

Rank the following structures in order of decreasing electrophile strength

Answer to question 1

Answer to question 2

Electrophile:

In organic chemistry, the electrophilic atom is usually a carbon atom which is bonded to electronegative atoms such as nitrogen, oxygen and fluorine. In these kinds of molecules separation of charges (polarization) occurs. As a result of polarization, the carbon atom contains a partial positive charge while the electronegative atom contains a partial negative charge and the molecule is known as an electrophile.

Resonance:

In a conjugated molecule, the lone/pi-bond pair of electrons moves along sigma bonds within a molecule. It leads to different arrangements of electrons for the same molecules. It is called a resonance.

Inductive effect:

The introduction of electronegative atoms (nitrogen, oxygen or fluorine) causes a negative inductive effect which is the pulling of bond pair electrons through sigma bonds, making the carbon in a C=O bond more electrophilic. For example,

The introduction of alkyl groups causes a positive inductive effect which is the donation of electrons through sigma bonds, making carbon in a C=O bond less electrophilic. For example,

Step: 1

Partial Charge separations:

Resonance:

Explanation:

In a carbonyl functional group, the oxygen atom pulls the electrons away from the carbon atom, making the carbon atom more electrophilic in nature because the oxygen atom is more electronegative than the carbon atom.

The carbon atom in a protonated carbonyl group gets a positive charge due to its resonance structures.
Hint:

Rank the given structures in the descending order of electrophilic strength.
Step: 2

Descending order of electrophilic strength:

Explanation:

The protonated carbonyl group is the most electrophilic in nature because the carbon atom has full positive charge on it. So, it ranks the first in the descending order of electrophilic strength.

The carbon atom in fluorine substituted carbonyls is more electrophilic in nature due to the negative inductive effect. Hence, it ranks second in the descending order of electrophilic strength.

The alkyl substituted carbonyls are less electrophilic in nature due to the positive inductive effect. So, these molecules are ranked by increasing carbon chain length with the descending order of electrophilic strength.

Answer:

Answer to question 3

Step1:

Step 2:

Step 3:

Step 4:

Answer to question 4

Step 1:

Electrophile are those species which are electron deficient in nature and hence they have an affinity towards an electron rich compounds. Mostly electrophile are either neutral having incomple octet or they are positive charge on the central atom.

Step 2:

Cl atom beong electronegative decreases electron density of carbonyl group therefore it the most electrophile while in carboxylate ion due to the presence of negative charge electrophilic strength is least.

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