6.2.1 - Amines Flashcards
How do you name amines?
-amine or amino
Why are amines so
reactive?
The lone pair of electrons on the Nitrogen - due
to polar N-H bond
Why are amines so
reactive?
The lone pair of electrons on the Nitrogen - due
to polar N-H bond
What shape are amines
around the N? Bond angle?
Trigonal pyramidal, 107 degrees
due to lone pair on N
What kind of intermolecular
forces do amines have? Why?
Hydrogen bonding due to polar N-H bond and
lone pair of electrons on N atom.
Do amines have
intermolecular forces which
are stronger than or weaker
than alcohols? Why?
Weaker, as N has a lower electronegativity than
O → weaker hydrogen bonding
How can amines
act as bases?
The lone pair on the nitrogen atom accepts a
proton
How can/when do amines
act as nucleophiles?
When they bond with an electron-deficient C
atom (donate lone pair from N)
What is the product from the
basic action of an amine
with water?
RNH3
+
- ammonium ion, which forms a salt with
an anion
Write an equation for
methylamine reacting with
HCl.
methylamine + HCl -> methylammonium chloride
In order to be the strongest
base, what must a particular
amine have (out of a set of
amines)?
Greatest electron density around the N atom,
making it a better electron pair donor (attracts
protons more)
What effect do alkyl groups
have (on electron density
and base strength)?
Positive inductive effect - increase electron
density around N → stronger base
Place the following in order
of base strength (in
general): NH3
, 1o
amine, 2o
amine, phenylamine.
2
o
amine > 1o
amine > NH3
> phenylamine
How can primary amines
then form 2o
, 3o
amines and
4
o
ammonium ions?
Multiple substitutions; primary amine is a
nucleophile that attacks the original haloalkane
etc
What are the problems with
this method?
Not efficient as low yield of 1o
amine due to
multiple substitutions
