Conformation Flashcards
How can you change the conformation of a molecule?
You can change it without making or breaking bonds
Change conformation by rotation around a single bond
What is conformation restricted by?
Restricted by bond lengths, angles and dihedral (torsional) angles
What is the dihedral angle?
The angle between the C-H bonds on the front and back carbon atoms
Which conformation is torsional strain the largest
Eclipsed conformation
What is torsional strain?
The increase in potential energy due to repulsion between electrons in different bonds
The resistance to bond twisting
The more torsional strain- the more energy required to rotate the bond
What is conformational analysis and what is a problem that involves it?
The determination of the arrangement in space of the constituent atoms of a molecule that may rotate about a single bond
How many conformations are there for small and medium MW molecules?
Limited number of conformations
What makes more conformations possible?
More conformations are possible with increase in number of single bonds
What is the importance of conformation?
Chemical activity may depend on only one conformation
How many conformations are there for medium MW molecules?
What is this true for?
Large number of conformations and flexibility
This means it’s unlikely for a single conformation to be preferred
This is true for larger organic synthetic polymers (heterogeneous)
How many conformations are there for proteins and nucleic acids?
- what does conformation dictate for these?
Homogenous proteins and nucleic acids have evolved- only take up a single or small number of conformations
These dictate their properties
How can you change the conformation of a molecule?
You can change it without making or breaking bonds
Change conformation by rotation around a single bond
What is conformation restricted by?
Restricted by bond lengths, angles and dihedral (torsional) angles
What is the dihedral angle?
The angle between the C-H bonds on the front and back carbon atoms
Which conformation is torsional strain the largest
Eclipsed conformation
