17.5 Flashcards
amine
NH2 + lone pair
suffix - amine
e.g methylamine
nucleophile - lone pair
bronstead lowery base
proton acceptor
ammonia and amines
lewis base
electron pair donor
aromatic amines
benzene ring
e.g phenylamine
weaker base than ammonia
lone pair becomes part of delocalised electrons
preparation of aliphatic amines
from halogenoalkanes
- halogenoalkane, ethanol and ammonia
nucleophillic substituation
from nitriles
-reducing agent (LiAlH4) and dry ether
reduction reaction
base strenth of aliphatic amines
as the chain increases base strength increases
as the availability of the lone pair increases
base strength of aromatic amines
weaker than ammonia
reaction of amines with ethanoyl chloride
acylation reaction
conc methylamine sol
cold
forms
-N-methylethanamide
-methylammonium chloride
reaction of amines with copper ions
two stages
1-
ammonia and copper sulphate
-hexaaquacopper ions
two hydrogen removed by ammonia -hydrogen acceptor
forms neutral complex
hydroxide precpitate
2-
-tetraamminediaquacopper(II) ions
ammonia forms dative bond acts as a electron pair donor
replacing 4 water
same reactions with amines
reaction of amines with halogenoalkanes
primary to secondary to tertiary to quaternary
forms salt of an amine
then reacts again to form the amine
HOW MUCH DO YOU NEED TO KNOW
amino acids
soluble in water
act as a base or a aid
or H+ transfer from COOH to NH2 forming electriclay neutral as positive and negative charge - zwitterions
isoelectronic point
ph at which the zwitterion exists in an aqueous solution
low indicates it is predominately acidic
hazard
property of a substance than can cause harm to the user
risk
possible effect substance may cause
gringards reagent
RMgX
formed from halogenoalkane and magnesium which is covalently bonded to both
unstable and react with water so have to be prepared before in a solved of dry ether
dilute acid added after reaction is complete
