phenols Flashcards
why is phenol not an alcohol
as an alcohol is a aliphatic hydroxy compound, phenol is a aromatic hydroxy compound
what does phenol attract
électrophiles
what and why does phenol repel
nucleophiles as phenol contains electrons in delocalised ring
what can phenol act as
a weak acid
why is phenol more reactive than benzene
as it has an increased electron density in ring
why does phenol have low solubility in water
the hydroxy group is polar and forms hydrogen bonds with water but benzene is non-polar and unable to mix with water, benzene has larger size than OH
what does the bromination of phenol produce
2,4,6-tribromophenol
properties of phenol
weak acid
low solubility
what are electron donating groups
OH, NH2
what do electron donating groups do
force substitutions to happen on 2- and 4-
2- 4- directing effect
what are electron withdrawing groups
NO2
what do electron withdrawing groups do
force substitution to happen on 3-
3- directing effect
reagents of bromination of phenol
bromine water
conditions of bromination of phenol
room temp
what precipitate is formed from the bromination of phenol
white precip
equation for the bromination of phenol
phenol + 3Br -> 2,4,6-tribromophenol + 3HBr
why does bromine become polarised when reacting with phenol
as the lone pairs in the O in the OH group become partially delocalised into the the ring so electron density increases which makes Br more polarised
how does phenols shape occur
The lone pairs of electrons on the oxygen atom in the hydroxyl group can interact with the delocalized pi-electron system of the benzene ring, creating a new system with distorted electron density.
reagent of nitrogenation of phenol
HNO3
conditions of nitrogenation of phenol
room temp
equation of nitrogenation of phenol
phenol -> 2-nitrophenol or 4-nitrophenol
products of when phenol reacts with NaOH
sodium phenoxide (C6H5ONa) + H2O
products of when phenol reacts with Na2
sodium phenoxide (C6H5ONa) + H2
