17.1 Flashcards
what are the 3 structural isomers
functional group
chain isomerism
position isomerism
what are the 2 stereoisomers
geometric
optical
what are structural isomers
compounds with the same molecular formula but different structural formula
what are chain isomers
they have different patterns of branching in their carbon chains
what are positional isomers
the same functional group is attached to different carbon atoms in the chain
what are stereoisomers
same structural formula but atoms/groups are arranged differently in 3D
what are geometric isomers
their atoms/groups are attached at different positions on opposite sides of a C=C
what are optical isomers
non-superimposable mirror images of each other
define chiral
an atom in a molecule that means it’s a non-superimposable form
what are asymmetric carbon atoms
carbon atoms in a molecule that is joined to 4 different atoms/groups
what makes a molecule optically active
if it rotates that plane of polarization of plane-polarized light
define plane polarized light
monochromatic light that has oscillations in only one plane
define unpolarized light
has oscillations in all planes at right angles to the direction of travel
what is a polarimeter
the apparatus used to measure that angle of rotation caused by a substance
what is a racemic mixture
an equimolar mixture of two enantiomers that has no optical activity
what is an analyser
a material that allows plane polarized light to pass through it
whats the one difference in chemical properties of enantiomers
the way in which they react with enantiomers of other substances
what is the one difference in physical properties of enantiomers
they rotate plane polarized light by the same angle in opposite direction
what is a racemic mixture
an equimolar mixture of two enantiomers that has no optical activity
what does SN2 stand for
S - substitution
N - nucleophilic
2 - biomolecular & 2nd order
what does bimolecular mean
two species are involved in the rate determining step
what occurs to the arrangement if the 3 groups attached to the central carbon in an SN2 reaction
the groups become inverted
why is the optical activity of the product different from the reactant
due to the inversion of the molecule
if the reactant of an SN2 reaction is dextrorotary what is the product
laevorotatory
if the reactant of an SN2 reaction is laevorotatory what is the product
dextorotatory
what does SN1 stand for
S - substitution
N - nucleophilic
1 - unimolecular & 1st order
what does unimolecular mean
inly one species is involved in the rate determining step
explain why there are 2 products formed in an SN1 reaction
the original halogenoalkane has a tetrahedral shape but then creates a carbocation with a planar shape meaning there is equal chance of the OH attacking from the L or the R in equal numbers
what mixture is formed from an SN1 reaction
racemic mixture
what happens to optical activity when an SN1 reaction occurs
the products optical activity is 0 due to the racemic mixture that is formed
which mechanisms occur for primary, secondary & tertiary halogenoalkanes
primary - SN2
secondary - SN1 & SN2
tertiary - SN1
