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262 Chapter 8
Copyright © 2017 Pearson Education, Inc.
Hückel’s rule or
a rule that gives the number of
p
electrons a compound must have in its
p
cloud
the 4
n
2
rule
to be aromatic.
isolated double bonds
double bonds separated from one another by more than one single bond.
kinetic control
when a reaction is under kinetic control, the relative amounts of the products de-
pend on the rates at which they are formed.
kinetic product
the product that is formed the fastest.
linear combination of
the combination of atomic orbitals to produce molecular orbitals.
molecular orbitals (LCAO)
localized electrons
electrons that are restricted to a particular locality.
lowest unoccupied
the lowest-energy molecular orbital that does not contain electrons.
molecular orbital
(LUMO)
pericyclic reaction
a reaction that takes place in one step as a result of a cyclic reorganization of
electrons.
phenyl group
C
6
H
5
polyene
a compound that has several double bonds.
polymer
a large molecule made by linking many small molecules together.
polymerization
the process of linking many small molecules to form a polymer.
proximity effect
an effect caused by one species being close to another.
resonance
electron delocalization.
resonance contributor
a structure with localized electrons that approximates the true structure of a
(resonance structure)
compound with delocalized electrons.
resonance electron
donation of electrons through
p
bonds.
donation
resonance electron
withdrawal of electrons through
p
bonds.
withdrawal
resonance energy
the extra stability a compound possesses as a result of having delocalized electrons.
(delocalization energy)
(resonance stabilization
energy)