Organic reagents Electrophilic ,Nucleophilic , Free radicals
Organic reagents are categorized into three sections according to their charge as electrophile ,nucleophile and free radicals. Electrophiles have less electrons density, nucleophiles have high electrons density and free radicals don't have special charge. But free radicals are very reactive and react very fast.
- Electrophilic reagents( electrophile )
- Nucleophilic reagents(nucleophile)
- Free radicals
Electrophilic reagents( electrophile )
Groups which have less density of electrons or positive charges, are called electrophilic reagents. Electrophilic reagents can attract electron from lewis alkaline compounds(NH3) or high electrons density compounds (alkenes, benzene ring in the phenol or aniline).
Examples of electrophilic reagents
Reactions of electrophilic compounds
The first step of benzene nitrosation. In this step Π electrons of benzene make a bond with +NO2 to form C-N bond.
Nucleophilic reagents(nucleophile)
Groups which have high density of electrons or negative charges or ,lone electron pair are defined as nucleophilic reagents. Nucleophilic reagents have the ability to accord electron to less electron groups.
Examples of nucleophilic reagents
Reactions of nucleophilic reagents
in the reaction of aqueous NaOH and alkyl bromide reaction OH- ion behaves as a nucleophile and give a alcohol as the product.
Free radicals
Groups which have unpaired valence electron are called free radicals . Free radicals are very reactive than electrophilic reagents and nucleophilic reagents. Free radicals are formed at the time reaction occurs.
Examples of electrophilic reagents
Reactions of free radicals
Methane chlorination under sun light. Many free radicals such as Cl., .CH3, .CH2Cl and more forms.
Free radicals forms in photochemical smog which exist in high traffic cities.
Questions
What is the difference between nucleophile and electropositive and electronegative?
Atoms can be charged positively or negatively. Positively charged atoms attrack negatively charged atoms. (negative ion or having lone pairs). So, we called those positively charging as electropositive charge.
Now you now, electronegative means a atom is charged negatively and attrack positive ions. Therefore we define those negatively charged parts as nucleophile.
Is Aluminium chloride an electrophile?
Yes. Aluminium chloride (AlCl3) is a electrophile. Also AlCl3 is Lewis acid.
Free radicals electrophilic and acidic?
If a compound has an acidic property, it should have the ability of removing H+ ions. Therefore, free radicals are not acidic.
Electrophiles like to attack negatively charged parts. Free radicals are unstable because their last shell is not complete. Free radicals do not attack negatively charged parts or groups. So free radicals are not electrophile.