Isomers Flashcards
Compounds that have the same connectivity between their atoms and differ only in the way their atoms are orientated in space.
Stereoisomers
Compounds that share only a molecular formula
Structural / constitutional isomers
Another word for cis-trans isomers
Geometric isomers
Z is to ___ isomers
E is to ____ isomers
Cis
Trans
A molecule that js not superimposable upon it’s mirror image
Chiral
Mirror images that can be superimposed
Achiral
Pairs of chiral molecules that are not superimposable mirror images
Enantiomers
Horizontal lines indicate bonds projecting _____ the page while vertical lines indicate bonds projecting ____ the page
Out of
Into
The configuration of a chiral molecule in relation to another chiral molecule
Relative configuration
The spatial arrangement of the atoms or groups within the chiral molecule relative to one another
Absolute configuration
If a compound has the ability to rotate plane polarized light it is ____
Optically active
Compound rotating polarized light to the right or clockwise
Dextrorotatory (+)
Compound rotating light to the left
Levorotatory (-)
Amount of rotation of light depends on the number of molecules the light encounters and depends on 2 factors
Length of tube the light passes through
Concentration of optimally active compound
For n chiral centres there are ___ possible stereoisomers
2^n
Stereoisomers that are not mirror images
Diastereomers
Diastereomers differing at only one carbon make up pairs of
Epimers
Molecules with multiple chiral centres having an internal plane of symmetry
Meso compounds
Compounds differing only by rotation about one or more sinner bonds
Conformational isomers
What is more stable
Staggered anti or gauche
Gauche or totally eclipsed
Anti
Gauche
What will slow conformation inter conversion
Low temperatures
Ring strain arises from 3 things
Angle strain
Torsional strain : eclipsed interactions (steric)
Nonbonded strain: when atoms or groups compete for the same space
In the boat the atoms are ____ (high energy ) while In the chair they are in the ___
Eclipsed
Staggered gauche
with bulky mono substituted cyclohexanes, what position is factored ?
Equatorial
