Question

When an organic molecule is irradiated with ultraviolet radiation, the energy absorbed by the molecules causes what type of change in the molecule (specifically explain the specific types of excitations the molecule experiences)? Explain your answer

Answer 1

Organic molecules which absorb UV radition and get excited are mostly alkenes

This is because we have pi electrons , non bonding electrons.

Electron gets excited jumps from orbital to another orbital

Excitation happens to pi electrons which get excited pi bonding orbital to pi anti bonding orbitals

Another exciatation is from non bonding orbital n to pi antibonding orbitals

( pi --> pi*   or n---> pi*)       where * represnet antibonding orbital

Other excitationw whcih require more energy are also possible

( sigma --> sigma* , n ---> sigma*) ,