Vibrational Soectroscopy Flashcards
How do atoms vibrate around equilibrium position
Like springs
What is Hookes law
F=-k (r-re)
What is potential energy
1/2k(r-re)
What is the force constant
Stiffness of spring/ strength of bond
What does potential energy mean
Energy due to position
What is total energy at turning points and equilibrium distance
PE and KE
If a bond is weak what is k (force constant)
Small
What is vvib
1/2pi roots/u
How are energy levels spaced
Moderately
What region is vibrational in
Infra red
What is a diatomic harmonic oscillator
A diatomic that obeys hookes law
What is Ev =
(V+0.5)vibrational wave number
What is V
Vibrational quantum number
What is vibrational wavenumber
Dependent on molecule
What is delta Ev
Vibrational wavenumber
Is v ever equal to zero
No, so molecule always have vibrational energy
What is the gross selection rule
Must change dipole on vibration
What is the specific selection rule
Change in v -+1
How many band appear
1
What is a diatomic vibrating rotor
Both rotating and vibrating
What approximation is used to sum the energies of vibrating rotors
Born Oppenheimer
What does the spectrum look like for a vibrating rotor
1 band for vibrating with fine structure for rotational
What are the J branches
P q and R
What can be observed in fine structure
Isotope peaks