Isomerism
1.0 Isomerism
2.0 Structural Isomerism
2.1 Chain or Nuclear Isomerism
2.2 ${C_5}{H_{12}}$ stands for three chain isomers
2.3 Cyclohexane and methyl cyclopentane are nuclear isomerism
2.4 Position Isomerism
2.5 Functional Isomerism
2.6 Metamerism
2.7 Ring Chain Isomerism
3.0 Tautomerism
3.1 Structural requirement for tautomrism
3.2 Cause of tautomerism
3.3 Keto-enol tautomerim
3.4 Percentage Composition of Tautomeric Mixture
3.5 Triad System containing Nitrogen
3.6 Mechanism of tautomerism
3.7 Stereoisomerism
3.8 Geometrical Isomerism
3.9 Reason of Occurrence of geometrical Isomerism
4.0 Geometrical isomerism in the compounds containing C=N
4.1 Geometrical isomerism in the compounds containing N=N
4.2 Geometrical Isomerism in Cyclic Compounds
4.3 Stability of cis, Trans (or) Geometrical isomers
4.4 Number of Geometrical isomers
4.5 E and Z nomenclature of geometrical isomers
5.0 Optical Isomerism
5.1 Optical Activity
5.2 Asymmetric carbon (or) Chiral Carbon
5.3 Optical isomerism in bromo chloro iodo methane
6.0 Optical isomerism in compounds having more than one chiral carbons
6.1 Elements of symmetry
6.2 Centre of Symmetry
6.3 Stereoisomerism in Tartaric Acid
6.4 Calculation of number of optical isomers
7.0 Optically active compounds having no asymmetric carbon
3.2 Cause of tautomerism
2.2 ${C_5}{H_{12}}$ stands for three chain isomers
2.3 Cyclohexane and methyl cyclopentane are nuclear isomerism
2.4 Position Isomerism
2.5 Functional Isomerism
2.6 Metamerism
2.7 Ring Chain Isomerism
3.2 Cause of tautomerism
3.3 Keto-enol tautomerim
3.4 Percentage Composition of Tautomeric Mixture
3.5 Triad System containing Nitrogen
3.6 Mechanism of tautomerism
3.7 Stereoisomerism
3.8 Geometrical Isomerism
3.9 Reason of Occurrence of geometrical Isomerism
4.2 Geometrical Isomerism in Cyclic Compounds
4.3 Stability of cis, Trans (or) Geometrical isomers
4.4 Number of Geometrical isomers
4.5 E and Z nomenclature of geometrical isomers
5.2 Asymmetric carbon (or) Chiral Carbon
5.3 Optical isomerism in bromo chloro iodo methane
6.2 Centre of Symmetry
6.3 Stereoisomerism in Tartaric Acid
6.4 Calculation of number of optical isomers
Migration of acidic hydrogen from $\alpha - $carbon to electronegative atom which is bonded with multiple bond is the cause of tautomerism and this phenomenon is known as tautomerism.
(i) Both (I) and (II) are isomers known as tautomers.
(ii) Tautomers are always in equilibrium state.
(iii) Number of sigma, pi and lone pair of electrons in both tautomers are always same.
(iv) Tautomerism is a chemical phenomenon which takes place only in liquid state.
(v) Tautomersim is catalysed by acid as well as base.
(vi) Tautomers are always reversible functional groups, functional isomers.
Tautomerism is of several types the two important types are dyad and triad systems.
(a) Dyad System: It involves the oscillation of $H$ atom between two polyvalent atoms, e.g., hydrogen cyanide (I) and hydrogen isocyanide (II).
In the above example the H atom vibrates between carbon and nitrogen atoms. The alkyl derivatives of (I) are called cyanides while those of (II) isocyanides.
(b) Triad System: In it one $H$ atom oscillates between three polyvalent atoms.
