L84- Aromatic chemistry Flashcards
Why do we synthesise thyroxine?
- Hypothyroidism – obesity and lethargy (thyroxine)
- Hyperthyroidism – weight loss and excess energy (thyroid removal)
what type of mechanism occurs to form thyroxine?
electrophilic aromatic substitution, using iodine and iodoperoxidase and h2o2
what type of bonding is sp2 hybridisation?
double bonding, due to 1 unchanged pi orbital,
what rule is used to see if a compound is aromatic?
Huckels Rule
-(4n + 2), conjugated and be planar (no sp3 bonds allowed so no single bonds, can have atoms with lone pairs)
what special about pyridine?
it has a lone pair of electrons
does have benzene have a good reactivity?
has low reactivity than alkenes
what reaction an occur with cyclohexane and bromine?
bromination, addition on the double bond
why can’t bromine react with benzene?
because bromine is a poor electrophile, using a catalyst such as AlCl3 it converts bromine to a good electrophile
why can alkenes react but benzene can’t?
benzene is stable and the electrons are delocolised
what does the catalyst do in order for bromination reaction with benzene to work ?
the catalyst AlCl3 is used to polarise the bromine-bromine bond to give a positively charged electrophile. so a Lewis acid is added.
Br–Br+–AlCl3-
how do you known what type of reaction has occurred on an energy profile graph? exothermic or endothermic
the energy of the end or reaction is lower than at the start for exothermic reactions
what is Delta G equal to on an energy profile graph?
activation energy
