organic chemistry Flashcards
SN1
the RDS contains one molecule (halogenoalkane)
secondary and tertiary halogenoalkanes
planar carbocation intermediary
OH- can attack from above or bellow the plane
racemic mixture is formed so no optical activity
SN2
the RDS contains two molecules (OH- and halogenoalkane)
primary and secondary halogenoalkanes
5 point transition state as halogen leaves and OH- attaches
arrangement of attached groups in inverted
only one enantiomer is formed
optically active product
rate of SN1
rate=k[C4H9Br] 1st order
rate of SN2
rate=k[C4H9Br] 2nd order
free radical substitution
alkane-> halogenoalkane
H replaced by halogen
requirs UV light
free radicle substitution of bromopropane and bromine
initiation:
Br-Br-> 2Br’
propagation
C3H7Br+Br’-> C3H6Br’ +HBr
C3H6Br’+Br2->C3H6Br2+Br’
termination:
Br’+Br’->Br2
C3H6Br’+Br’->C3H6Br2
C3H6Br’+C3H6Br’->C6H12Br2
electrophilic addition
alkene + HX or X2 -> halogenoalkane
nucleophilic substitution
halogenoalkane
plus KOH, CN-, NH3, H2O, OH-
if unsymmetrical then a major and minor product can be formed
chiral meaning
forms two non superimposable isomers
sigma bonding
head on overlap of orbitals
(s or p)
pi bonding
side on overlap of orbitals
bonding in a double bond
one sigma, one pi
geometric isomerism
a form of stereo isomerisms
cis trans
optical isomerism
form of stereo isomers
enantiomers
