Home work Physical and Theoretical Chemistry IV

- Molecular Spectroscopy -

Discussion  Fr 21.01.2005 at 10:30,  PK11-2



  Home work 9            Rotational Structure of Electronic Transitions. Photoelectron spectroscopy
 

Exercise 1:       

a)  The rotational constant B in the ground state of OH radical is 18.8 cm-1. Using the Boltzmann formula show which rotational energy level J has the greatest population at the room temperature?    

b) Consider the optical electronic transition between the OH ground state  2Π and the first excited state  2Σ .  Which rotational branches contains the UV absorption spectrum of this transition?  What will be the behavior of the rotational P and R branches if the rotational constant of the excited state is 17.3 cm-1 ?   Calculate the value of corresponding R branch band head 

Exercise 2:   

a)   Consider the ionization of N2 molecule from the 3σg bonding orbital (HOMO) with synchrotron radiation at λ=50 nm.  What will be expected maximum kinetic energy of photoelectrons if  the ionization energy of the molecule is Ii =15.59 eV. Give the result in eV.

b)  What will be the electron kinetic energy if the molecular ion N2+ in the above problem  is produces in its v'=2 vibrational energy state?  The vibrational constant of the molecular ionic state is ωe' = 2207 cm-1?

c)  What will be the maximum kinetic energy of the photoelectrons if  N2 molecule is ionized from the inner 1pu bonding orbital which has 1.1 eV lower energy than the 3σg bonding orbital?