optical isomerism Flashcards
what is optical isomersm
optical isomerism is a form of stereoisomerism
molecules with chiral centers that are non-superimposable mirror images, rotate the plane of polarised light in opposite direction as one isomer will rotate clockwise and one isomer will rotate it anti-clockwise
why does optical isomerism occur
as a result of chiral center ( carbon atom bonded to 4 different groups)
define racemic mixture
a mixture which contains equal quantities of enantiomers
how racemic mixtures are formed
PEAR
bonding about (…) group is planar
equal chance of nucleophile attacking one side from the other
so equal proptions of each optical isomer so racemic mixture formed
why are racemic mixtures optically inactive
as rotation of polarised light cancells out
define chiral
a molecule which can exist as a pair of optical isomers is called chiral
define chiral center
the carbon which is attached to 4 different groups is called the chiral center
define stereogenic centre
another name for chiral cnetre
define asymetrical carbon
another name for a chiral center
define enantiomer
another name for each optical iosomer
define enantiometrically pure
if a sample only contains one optical isomer
define optically acitve
an enantiomerically pure compund
will rotate the plane of polarised light in one direction only
