Basic Principles of Organic
Elements and Compounds
Structure
of Atom
Element
Chemistry
Fundamental Concepts in Organic Reaction
Mechanism
Objectives:
Compounds
Electronic
displacement
covalent
A compound
is a substance in
composed
of two or
more elements, chemically combined with one
bond.
another in a fixed proportion.
Fission
of covalent
bond.
Water, sugar,
salt, carbon
dioxide,
methane etc are the examples of
compounds.
Carbocation and carbanion.
Basic Principles of Organic
Elements and Compounds
Structure
of Atom
Element
Chemistry
Fundamental Concepts in Organic Reaction
Mechanism
Electronic Displacement in Covalent Bond
Compounds
Four types of electronic displacement is found in mechanism of
organic
reactions: is a substance composed of two or
A compound
more elements, chemically combined with one
Inductive
another ineffect
a fixed proportion.
Electromeric
Water, sugar,effect
salt, carbon dioxide,
methane etc are the examples of
Resonance
or Mesomeric effect
compounds.
Hyperconjugation
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
ElementChemistry
Oil
DiagonalConcepts
Relationship
and Reaction
Fundamental
in Organic
Extraction
of
Sulphur
Compounds
Lithium
Homologus
and
of
Sodium
Series
Calcium
Mechanism
Irregularity
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Inductive
effect
Compounds
Inductive effect may be defined as the permanent displacement of
electrons forming a covalent bond towards the more electronegative
A compound
element
or group. is a substance composed of two or
more
elements,
chemically
with
one
The
inductive
effect is represented
bycombined
the symbol, the
arrow
pointing
towards
more
electronegative element or group of
another
in athe
fixed
proportion.
elements.
Water, sugar, salt, carbon dioxide,
methane etc are the examples of
compounds.
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
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Inductive
effect
Compounds
Any atom or group, if attracts electrons more strongly than
hydrogen, it is said to have a -I effect (electron-attracting or
A compound is awhile
substance
composed
of two or
electron-withdrawing)
if atom or group
attracts electrons
less
strongly
than hydrogen
it is said to
have +I effect
(electron
more
elements,
chemically
combined
with
one
repelling or electron-releasing).
another in a fixed proportion.
Water, sugar, salt, carbon dioxide,
methane etc are the examples of
compounds.
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
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Electromeric effect
Compounds
Electromeric effect refers to a molecular polarizability effect
occurring by an intramolecular electron displacement
characterized by the substitution of one electron pair for another
within the same atomic octet of electrons.
Positive electromeric
effect (+Esugar,
effect) salt,
Water,
carbon dioxide,
methane etc are the examples of
compounds.
Negative electromeric
effect (-E effect)
Mineral
Coal and
Basic
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of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
Petroleum
Electromeric effect
Compounds
Water, sugar, salt, carbon dioxide,
methane etc are the examples of
compounds.
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
Petroleum
Resonance or Mesomeric effect
Compounds
The electron withdrawing or releasing effect attributed to a
substituent through delocalization of p or π electrons, which can
be visualized by drawing various canonical forms, is known as
mesomeric effect or resonance effect.
Resonance effect is shown by a symbol ↔.
Two resonance
structures
of Benzene
Water, sugar,
salt, carbon
dioxide,
methane etc are the examples of
compounds.
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
Petroleum
Resonance or Mesomeric effect
Compounds
Water, sugar, salt, carbon dioxide,
methane etc are the examples of
compounds.
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
Petroleum
Hyperconjugation
Compounds
Hyperconjugation is the interaction of the electrons in a sigma
bond (usually C–H or C–C) with an adjacent empty (or partially
filled) non-bonding p-orbital, antibonding π orbital, or filled π
orbital, to give an extended molecular orbital that increases the
stability of the system.
Only electrons in bonds that are β to the positively charged carbon
can
stabilize
a carbocation
by hyperconjugation.
Water,
sugar,
salt, carbon
dioxide,
methane etc are the examples of
compounds.
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
Petroleum
Hyperconjugation
Compounds
Water, sugar, salt, carbon dioxide,
methane etc are the examples of
compounds.
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
Petroleum
Fission of Covalent Bond
Compounds
Breaking of covalent bond of the compound is known as bond
fission. A bond can be broken in two ways.
Fission of
Covalent Bond
Water, sugar, salt, carbon dioxide,
methane etc are the examples of
compounds.
Homolytic
Fission
Heterolytic
Fission
Mineral
Coal and
Basic
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of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
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Series
Calcium
Mechanism
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Homolytic Fission or Homolysis
Compounds
The covalent bond is broken in such a way that each resulting
species get its own electron. This leads to the formation of the odd
electron species called free radicals.
Water, sugar, salt, carbon dioxide,
methane etc are the examples of
compounds.
The free radicals are highly reactive species and have a
short life.
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
Petroleum
Heterolytic Fission or Heterolysis
Compounds
The covalent bond is broken in such a way that one species (less
electronegative) is deprived of its own electron, while other species
gains both the electrons. Thus, the formation of opposite charged
species takes place.
Water, sugar, salt, carbon dioxide,
methane etc are the examples of
compounds.
Incase of organic compounds, if positive charge is present on the
carbon, then cation is termed as carbocation. If negative charge is
present on the carbon, then anion is termed as carbanion.
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
Petroleum
Carbocation or Carbonium ion
Compounds
A species in which a carbon
atom has only six electrons
in its valence shell and bears
positive charge is called a
carbocation.
Water, sugar, salt, carbon dioxide,
methane etc are the examples of
compounds.
Carbocations are classified as 1°, 2°, or 3° depending on the
number of carbons bonded to the carbon bearing the positive
charge.
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
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Series
Calcium
Mechanism
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Carbocation or Carbonium ion
Compounds
 Bond angles about a positively charged carbon are
approximately 120°.
 Carbon uses sp2 hybrid orbitals to form sigma bonds to the
three attached groups.
 The unhybridized 2p orbital lies perpendicular to the sigma
bond framework and contains no electrons.
Water, sugar, salt, carbon dioxide,
methane etc are the examples of
compounds.
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
Petroleum
Carbocation or Carbonium ion
Compounds
Water, sugar, salt, carbon dioxide,
methane etc are the examples of
compounds.
Methyl and 1° carbocations are so unstable that they are never
observed in solution.
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
Petroleum
Carbocation or Carbonium ion
Compounds
Water, sugar, salt, carbon dioxide,
The relativeetc
stability
carbocations
can
methane
are of
the
examples
ofbe explained using the
fact that alkyl groups bonded to the positively charged carbon
compounds.
are electron releasing and thereby delocalize the positive
charge of the cation.
The electron-releasing ability of alkyl groups is accounted by
(1) the inductive effect, and (2) hyperconjugation
Mineral
Coal and
Basic
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of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
Petroleum
Carbanion
Compounds
A carbanion is an anion in which carbon has an unshared pair of
electrons and bears a negative charge usually with three
substituents for a total of eight valence electrons.
Water, sugar, salt, carbon dioxide,
methane etc are the examples of
compounds.
When a negatively charged carbon atom is directly attached to one
, two or three alkyl groups then these are called primary (1°),
secondary (2°) and tertiary (3°) carbanions respectively.
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
Petroleum
Carbanion
Compounds
Carbanions are trivalent
with sp3 hybridization. The
lone pare of electrons
occupies one of the sp3
orbitals. The geometery is
thus tetrahedral. The
Water, sugar,
salt, carbon dioxide,
tetrahedron
can undergo
inversion
oretc
retain
itsthe examples of
methane
are
stereochemistry
compounds.
depending on the attached
substitutents.
Mineral
Coal and
Basic
Principles
of Mineral
Organic
Elements
and
Compounds
The
s-Block
Elements
Non-metals
Structure
ElementChemistry
Oilof Atom
Fundamental Concepts in Organic Reaction
Extraction
ofofSulphur
Compounds
Lithium
Homologus
and
Sodium
Series
Calcium
Mechanism
Petroleum
Carbanion
Compounds
Water,
sugar,
salt, carbon
dioxide,
Alkyl groups
has electron
releasing
tendency (due to +I effect),
and therefore,
electron density
methane
etcincreases
are thethe
examples
of on the negatively
charged carbon atom and hence stability decreases.
compounds.
More the number of alkyl groups attached to the negatively
charged carbon atom greater will be the electron density on the
carbon atom and lower will be its stability.