(1) Sigma Bond:
(2) Pi (π)-Bond:
(3) Delta Bond:
Delta Bond: Delta bond is a special type of bond which is formed by overlapping of all the four lobes of d-orbitals except dz2 orbital.
Friday, October 16, 2020
What is Delta Bond ?
According to Valance bond theory (VBT) by overlapping of atomic Orbitals three types of covalent bond formation take place.
What is Pi-(π)Bond ?
According
to Valance bond theory (VBT) by overlapping of atomic Orbitals three types of
covalent bond formation take place.
(1) Sigma Bond:
(2) Pi (π)-Bond:
(3) Delta Bond
Pi(π)
Bond:
(1) Pi (π) bond formed by
sideways/lateral overlapping of pure atomic orbitals except Benzene where
hybrid orbital formed π- bond.
(2) Lateral overlapping is only partial, so bonds formed are weaker and
hence more reactive than sigma bond (repulsion between nucleus is more as
orbitals have to come much close to each other for pi bond formation).
For
example-formation of oxygen molecule. Only Py and Pz of oxygen atom have
unpaired electron in each orbital for bonding.
Electronic
configuration of oxygen atom is 1s2,2s2,2Px2,Py1,Pz1
(3) Free rotation about a pi bond is not possible.
(4) pi bond is weaker than sigma bond .
(5) pi bond takes part in resonance.
(6) pi bond formed by pure or unhybrid orbitals.
Type
of π- bond:
(1)
Pπ-Pπ bond:
(2)
Pπ-dπ bond:
(3)
dπ-dπ bond:
What is Sigma Bond ?
According
to Valance bond theory (VBT) by overlapping of atomic Orbitals three types of
covalent bond formation take place.
(1) Sigma Bond:
(2) Pi Bond:
(3) Delta Bond:
Sigma
Bond:
(1)The sigma bond formed by nuclear/head on/axial overlapping /end
to end overlap of pure as well as hybrid atomic orbitals.
(2) Sigma bond do not involve in resonance.
(3) free rotation is possible about a single sigma bond.
(4) Maximum overlapping is possible between electron clouds and
hence it is strong bond.
(5) There can be only sigma bond between two atoms and sigma
bond are formed by three type of overlapping.
(A) S-S
overlapping: Two half filled s-orbitals
overlap along inter nuclear axis for example H2 molecule.
(B) s-p
overlapping : When half filled s-orbital
of one atom overlap with half with p-orbital of other atom for example HF
molecule.
(C) p-p
overlapping (Coaxial overlapping): it
involves the coaxial overlapping between half filled p-orbitals of two
different atoms for examples F2, Cl2, Br2 etc
What is Pi-(π)Bond ?
What is "COORDINATE BOND" ?
A co-ordinate bond formed between two species by sharing of an electron pair where shared pair electron is given by one but shared by both.
ILLUSTRATIVE EXAMPLE (1):
ILLUSTRATIVE EXAMPLE (1):
ILLUSTRATIVE EXAMPLE (1):
ILLUSTRATIVE EXAMPLE (1):
ILLUSTRATIVE EXAMPLE (1):
CONCLUSIONS:
(1) Atoms of second period elements follow octed rule in doing so either they accept co-ordinate bond or they form co-ordinate bond. However atoms of 3rd period elements perfectly form double bond (pi bond) in the place of co-ordinate bond if direction of co-ordinate bond is from centre to substituent.
(2) If maximum covalency rule applied and pi bonds have formed then back bond is not considered in species
For example H2SO4 and HClO4 have no back bond there is double bond.
Related
Questions:
Why all the
tetrahedral Complexes are high spin Complexes?
Why Fe(CO)5 is colourless
while Fe(bipy)(CO)3 is intensely purple in colour ?
Why [Mn(H2O)6]+2 is colourless
although in which Mn+2 ion had five unpaired electrons ?
Why [FeF6]3– is colourless whereas [CoF6]3–
is coloured?
Why [Ni(CN)4]-2 is colourless
while [Ni(H2O)4]-2 is colour although both have +2
oxidation state and 3d8 configuration ?
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