Organic compounds are vital for life and include substances like DNA, proteins, fuels, polymers, dyes, and medicines. Carbon has the unique ability to form covalent bonds with itself and other elements through a process called catenation. The shapes of organic molecules like methane, ethene, and ethyne are determined by the hybridization of carbon - methane is tetrahedral due to sp3 hybridization, ethene is planar due to sp2 hybridization, and ethyne is linear due to sp hybridization. Hybridization also influences bond lengths and energies. π-bonds form through parallel sideways overlap of p-orbitals on adjacent carbons and have electron density above and below the plane of the bonded atoms

1. ORGANIC CHEMISTRY
Basic Concepts
Janardhan Acharyulu
PGT(Chemistry)
K V KANCHANBAGH

2. General introduction
Organic compounds are vital for life like genetic
bearing DNA and protein essential in our blood ,
muscles and skin

Organic chemicals like clothing,fuels,polymers,dyes
and medicines

First F Wholer synthesized an organic compound
UREA from an inorganic compound ammonium
cyanate
NH₄CNO
NH2 CONH2


3. Synthesis of acetic acid by Kolbe and methane by
Berthelot showed that organic compounds could be
preapred from inorganic synthesis

Carbon has the unique property called catanation
which forms covalent bonds with other carbons and
atoms like H,O,N,S, halogens etc


4. Shapes of organic compounds
Tetra valence of Carbon and the formation
of covalent bonds by it are explained in
terms of electronic configuration and
hybridizationof s and p orbitals

Formation and shapes of molecules Methane, Ethene and
Ethyne are exlpained in terms of sp³ , sp² and sp hybrid
orbitals by carbon in respective molecules


5. 

A molecule of
methane contains
four C-H ᓂ bonds
On the basis of sp³
hybridization of carbon atom
the structure of methane
molecule is predicted to be
Tetrahedral

6. 

Structure of ethane
Ethane contains six
C-H ᓂ bonds and
one C-C ᓂ bond

7. 
Structure of ethene
explained to be planar on
the basis of sp²
hybridization one C-C ᓂ
bond and one c-c Ꙥ
bond


8. 
Structure of ethyne to
be linear on the basis of
sp hybridization, the
carbon carbon triple
bond of ethyne
consists of one C-C ᓂ
bond and two C-C Ꙥ
bonds, the Ꙥ bonds
are formed by
sideways overlap of
the p-orbitals

9. Hybridization influences bond length and enthalpy

The sp hybrid orbital contains more s- character and

closer to its nucleus and forms shorter and stronger
bonds than sp₃ hybrid orbital

The sp² hybrid orbital is inter mediate between sp and
sp³ , hence the length and enthalpy values are also
intermediate

The change in hybridization affects the elecro-vity of
carbon,the greater the s – character the greater is the -vity,

Thus a carbon atom having an sp hybrid orbital with 50%
of s-character is more electro-vity than the other hybrid
orbitals

10. Characteristic Features of Ꙥ-
bonds
For Ꙥ bond formation it is essential that the porbitals on the adjacent carbon atoms must be
parallel for a parallel sideways overlap

Some of characters are

(i) All the atoms directly attached to the carbon atoms of the
double bond lie in the same plane

(ii) The p-orbitals of a Ꙥ-bond are mutually parallel

and are perpendicular to the plane of the molecule

The electron charge cloud of the Ꙥ-bond lies above
and below the plane of the bonding atoms