Rotational spectroscopy Flashcards
What is needed to absorb microwave?
Dipole
What must molecules have to have a “pure” rotational spectrum?
Permanent dipole
Where are vibrational levels found?
In each electronic state
What does the electric field of an electromagnetic wave exert?
Torque on an electric dipole
What is a torque?
A turning force
What does a dipole become excited from?
Interaction with radiation field which induces a
What are the energy gaps between rotational levels like?
Smaller than vibrational levels
What is a moment of inertia?
The rotating body’s resistance to angular acceleration
What happens with something that has a higher moment of inertia?
More force is needed to turn it
What equation is used to work out the moment of inertia?
I = μR²
what is μ?
Reduced mass
What is R?
Internuclear distance
How does bond length link to moment of inertia?
The longer the bond, the higher moment of inertia
How do you work out the energy of rotational transition levels?
Measure between levels and not the actual levels
E = hJ(J+1)B
What is J in the equation?
The rotational energy levels
