stereoisomerism Flashcards
what have the same order of attachment of atoms but different arrangements of atoms in space
stereoisomerism
define stereoisomerism
have the same order of attachment of atoms but different arrangements of atoms in space
stereoisomerism is responsible for the significant difference in
chemical properties
effectiveness of … depends on stereoisomerism
drugs
stereoisomerism may have the presence/ absence of
side effects
which has a superimposable image
achiral
which do not have a superimposable image
chiral
which has a plane of symmetry
achiral
which does not have a plane of symmetry
chiral
what way is a quick way to tell if it’s chiral or not
plane of symmetry
which is able to rotate plane-polarized light
chiral (optically active substance)
which is not able to rotate plane-polarized light
achiral (optically inactive substance)
carbon with 4 different groups attached to it
stereogenic carbon / stereogenic center
what refers to a pair (chiral and mirror image) of molecules related as nonsuperimposable
enantiomers
pairs of compounds with exactly the same connectivity but opposite three-dimensional shapes
enantiomers
what refers to a plane that passes through a molecule
plane of symmetry/ mirror plane
plane of symmetry is where one side of the plane is the…
exact reflection of the other side
what is the ARRANGEMENT of 4 groups attached to a stereogenic center
configuration
is enantiomers a configuration or opposite configuration
opposite configuration
what refers to the specify of the configuration w/o having to draw the structure
R-S or Cahn-Inlog-Prelog System
what is the R-S / Cahn-Ingold-Prelog System conditions
observe from the side opposite of the lowest priority
how do you arrange them from highest to lowest priority
by looking at the atomic number
(R):
clockwise
(S):
counterclockwise
in the Cahn-Ingold-Prelog System, how do u rank them
rank the atoms attached too stereogenic center.
the higher the atomic number…
the higher the priority
in Cahn-Ingold-Prelog System, if the first step or decision could not be reached…
work outward from stereogenic center
in Cahn-Ingold-Prelog System, the double, triple bonds aromatic rings are treated as…
as equal no. of single bonds
what can contain 0 or 1 or more chirality centers
chiral molecule
what uses the same priority rule
the E-Z convention for cis-trans isomers
(E):
2 higher group are on the opposite side of double bond
(Z):
2 higher group are on the same side of double bond
what is the instruments used to detect optical activity
polarimeter/ spectropolarimeter
in the polarized light and optical activity,
what is able to rotate the plane-polarized light
optically active substances (chiral)
in the polarized light and optical activity,
what is unable to rotate the plane-polarized light
optically inactive substances (achiral)
in the polarized light and optical activity,
which rotates through an angle a
optically active substances (chiral)
2 enantiomers rotate plane-polarized light to a same…
to a same angle but opposite directions
the properties of enantiomers differ only with respect to
chirality
enantiomers are identical in terms of
BP,MP, solubility
what is the interchange of any 2 groups that always give the enantiomers
stereorepresentations
how to determine the absolute (R/S) configuration of stereoisomer
- check which has the highest priority (make sure that the H is at the vertical line)
- know if it’s clockwise or anticlockwise
what to do if the lowest priority is at the horizontal lines
you could rotate 3 of the 4 groups so that the lowest priority is at the vertical line
do compound with more than 1 chirality center have or dont have mirror image
have mirror image
do stereoisomeric forms have or dont have mirror image
dont have mirror image
based on my understanding, what is constitutional, configurational and identical
constitutional - completely different
configurational - geometric (cis/ trans) same mol. formula but diff attachment of atom
identical - everything is the same
An achiral compound with chiral centres
meso compounds
what are meso compounds
An achiral compound with chiral centres
what has an internal plane of symmetry that makes it superimposable on its mirror image and is optically inactive
meso compound
what is an isomers that has the same chemical formula but non superimposable mirror image of e/o
enantiomers
what is an arrangement of elements in a particular form
configuration
you automatically have one enantiomers when…
you have one chiral center
the enantiomers will always have different…
configuration
in the cahn-ingold-prelog rules, if the lowest priority is at the front…
need to reverse the direction.
both or all chiral centers has changed
and no internal plane of symmetry
enantiomers
differ by only one chiral centers
diastereomers
identical and have an internal plane of symmetry
meso compounds
in optical activity, positive or negative enantiomers if it rotates towards the right
positive
in optical activity, positive or negative enantiomers if it rotates towards the left
negative
if positive enantiomers, is it dextrorotary or levorotatory
dextrorotary
if negative enantiomers, is it dextrorotary or levorotatory
levorotatory
