Illustrated Glossary of Organic Chemistry
Pi* orbital (π* orbital):
The
antibonding molecular orbital
component of a
pi bond
.
The π* orbital of
ethylene's
carbon-carbon
pi bond
has four
orbital lobes
(two
orbital lobes
on each
sp
2
carbon atom). It is an
antibonding molecular orbital
. This π* orbital has two
nodes
: one
node
is the plane which contains the atoms, and the other
node
is a plane perpendicular to this, between the two carbon atoms.
The
π
orbital
of
ethylene's
carbon-carbon
pi bond
has two
orbital lobes
, one above the plane of the atoms, and another below the plane. This is a
bonding molecular orbital
. This same plane is the
pi
orbital's
one
node
.
Related terms:
Sigma orbital
,
σ orbital
,
sigma* orbital
,
σ* orbital
,
sigma bond
,
σ bond
,
atomic orbital
,
s
orbital
,
p
orbital
,
p
x
orbital
,
p
y
orbital
,
p
z
orbital
,
nonbonding molecular orbital
,
orbital electronegativity
,
Woodward-Hoffmann rules
,
pi electron
Wikipedia entries:
Molecular orbitals
,
pi orbital
Return to glossary index