Imidazole is more basic than pyridine? Why?

Imidazole and its derivatives form an interesting and important class of heterocyclic aromatic amines.

The basic strength of imidazole is approximately 100 times more basic than pyridine. Because protonation of imidazole yields an ion that is stabilized by the electron delocalization represented in the resonance structures given as below:

As seen in above figure the electrostatic potential map of the conjugate acid of imidazole (imidazolium ion) is consistent with the resonance description that shows both nitrogens as equivalent.

Related Questions:

Give an explanation for the fact that Guanidine NH=C(CH3)2 is a stronger base than most of amines?

Arrange in correct order of basic Character of aniline, pyrrol, pyridine and piperidine?

What is correct basicity order of pyridine, pyridazine, pyrimidine and pyrazine ?

Why pyridine is more basic than Pyrrole?

Why pyrimidine is less basic than pyridine?

Imidazole is more basic than pyridine? Why?

Biological Important of Imidazole and structure:

Pyridine is almost 1 million times less basic than piperidine? Why?

Cyclohexylamine amine is the stronger base than Aniline? Why?

Tetrahydroquinoline amine is the stronger base than Tetrahydroisoquinoline? Why?

Biological Important of Imidazole and structure:

Imidazole and its derivatives form an interesting and important class of heterocyclic aromatic amines.

An imidazole ring is a structural unit in two biologically important compounds, histidine and histamine. 

Histidine is one of the amino acid building blocks of proteins and is directly involved in key proton-transfer processes. The drop in blood pressure associated with shock is a result of the formation of histamine, which stimulates the dilation of blood vessels.

Related Questions:

Give an explanation for the fact that Guanidine NH=C(CH3)2 is a stronger base than most of amines?

Arrange in correct order of basic Character of aniline, pyrrol, pyridine and piperidine?

What is correct basicity order of pyridine, pyridazine, pyrimidine and pyrazine ?

Why pyridine is more basic than Pyrrole?

Why pyrimidine is less basic than pyridine?

Imidazole is more basic than pyridine? Why?

Biological Important of Imidazole and structure:

Pyridine is almost 1 million times less basic than piperidine? Why?

Cyclohexylamine amine is the stronger base than Aniline? Why?

Tetrahydroquinoline amine is the stronger base than Tetrahydroisoquinoline? Why?

Pyridine is almost 1 million times less basic than piperidine? Why?

We know that if nitrogen is part of an aromatic ring, however, its basicity decreases markedly.  So in pyridine nitrogen is part of an aromatic ring hence its basicity is much more less than piperidine. The difference between the two lies in the fact that the nitrogen lone pair occupies an sp3- hybridized orbital in piperidine versus an sp2-hybridized one in pyridine. As we have noted on several occasions, electrons in orbitals with more s character are more strongly held than those with less s character. For this reason, nitrogen holds on to its unshared pair more strongly in pyridine than in piperidine and is less basic.

Related Questions:
Give an explanation for the fact that Guanidine NH=C(CH3)2 is a stronger base than most of amines?
Arrange in correct order of basic Character of aniline, pyrrol, pyridine and piperidine?
What is correct basicity order of pyridine, pyridazine, pyrimidine and pyrazine ?
Why pyridine is more basic than Pyrrole?
Why pyrimidine is less basic than pyridine?
Imidazole is more basic than pyridine? Why?
Biological Important of Imidazole and structure:
Pyridine is almost 1 million times less basic than piperidine? Why?
Cyclohexylamine amine is the stronger base than Aniline? Why?
Tetrahydroquinoline amine is the stronger base than Tetrahydroisoquinoline? Why?

Cyclohexylamine amine is the stronger base than Aniline? Why?

We can say that aniline is a weaker base than cyclohexylamine because the electron pair on nitrogen of aniline is strongly held by virtue of being delocalized into the π system of the aromatic ring. The unshared pair in cyclohexylamine is localized on nitrogen, less strongly held, and therefore “more available” in an acid–base reaction.

Related Questions:

Give an explanation for the fact that Guanidine NH=C(CH3)2 is a stronger base than most of amines?

Arrange in correct order of basic Character of aniline, pyrrol, pyridine and piperidine?

What is correct basicity order of pyridine, pyridazine, pyrimidine and pyrazine ?

Why pyridine is more basic than Pyrrole?

Why pyrimidine is less basic than pyridine?

Imidazole is more basic than pyridine? Why?

Biological Important of Imidazole and structure:

Pyridine is almost 1 million times less basic than piperidine? Why?

Cyclohexylamine amine is the stronger base than Aniline? Why?

Tetrahydroquinoline amine is the stronger base than Tetrahydroisoquinoline? Why?

Tetrahydroquinoline amine is the stronger base than Tetrahydroisoquinoline? Why?

We can say that Tetrahydroisoquinoline  is a weaker base than Tetrahydroquinoline because the electron pair on nitrogen of Tetrahydroisoquinoline is strongly held by virtue of being delocalized into the π system of the aromatic ring. The unshared pair in Tetrahydroquinoline is localized on nitrogen, less strongly held, and therefore “more available” in an acid–base reaction.

Related Questions:

Give an explanation for the fact that Guanidine NH=C(CH3)2 is a stronger base than most of amines?

Arrange in correct order of basic Character of aniline, pyrrol, pyridine and piperidine?

What is correct basicity order of pyridine, pyridazine, pyrimidine and pyrazine ?

Why pyridine is more basic than Pyrrole?

Why pyrimidine is less basic than pyridine?

Imidazole is more basic than pyridine? Why?

Biological Important of Imidazole and structure:

Pyridine is almost 1 million times less basic than piperidine? Why?

Cyclohexylamine amine is the stronger base than Aniline? Why?

Tetrahydroquinoline amine is the stronger base than Tetrahydroisoquinoline? Why?