isomerism Flashcards
chain isomers
different lengths of carbon chains
positional isomers
position of the functional group changes
primary / secondary / tertiary compounds
count the number of carbon atoms bonded to this carbon atom
functional group isomers
atoms arranged in a manner that they have different functional groups
which compounds can be functional isomers of each other (3 x2 )
- hydroxyl and alkoxy
- ketones and aldehydes
- ester and carboxyl
stereoisomers
same molecular formula, connectivities and bond multiplicity. However there is different spatial arrangement of the atoms
conformational isomers
if molecule contains 2 groups bonded together by a single bond, these groups can rotate about the single bond to form different conformational isomers AKA conformers
configurational isomers def and what they consist of
can only be interconvereted by breaking and reforming bonds
Divided into cis-trans and optical isomers
cis trans occurs in
aliphatic alkenes groups bonded to the unsatured carbon atoms cannot rotate about the double bond
how cis isomer looks
two identical substituents are on the same side of the carbon - carbon double bond
how trans isomer looks
two identical substituents on opposite sides of the carbon carbon double bond
horizontal axis of a double bond is called
the reference plane
cis trans isomerism in disubstituted cycloalkane molecules
the reference plane is the flat face of the ring structure
cis - methyl on the same side
trans - methyl on the opp side
chiral carbon definition and AKA
carbon atom bonded to 4 different atoms/ groups / molecules
stereocentre / asymmetric centre
optical activity def + possesed by
the ability to rotate light, possesed by chiral carbons
penicillamine
drug used to treat rheumatoid arthritis
enantiomers
non - super imposable mirror images of each other that have no plane of symmetry
what cycloalkane exhibits optical and cistrans isomerism
1,2 - dimethyl cyclobutane
mirror images r non superimposable
properties of enantiomers
(odour and how chemical properties change)
- different enantiomers of the same compound have different odours
- The chemical properties are identical in non-chiral environments but become different in the presence of other chiral compounds
pair of enantiomers rotating ** plane polarized light **
under the same condition each entantiomer will rotate** plane polarized light ** by the same angle but opposite directions
one clockwise (+) enantiomer
anticlockwise (-) enantiomer
