Inorganic Chemistry, Structures and Spectroscopy

Answer All THREE parts $($a$)-($c$)$

$($a$)$ With the aid of a diagram, describe the theory behind Raman scattering. Include in your answer$-$

$($i$)$ the selection rules for Raman scattering;

$($ii$)$ the origin of the three types of scattering that can be observed in normal Raman scattering; and

$($iii$)$ the reason for the difference in intensities observed in the three types of scattering.

$[12]$

$($b$)$ Describe the basic principles of how a Raman instrument operates. Include in your description the key components that are required and their function.

$[6]$

$($c$)$ The Raman spectra shown below were obtained from a dye, BODIPY FL$,C_9{H}_7{N}_{2}B{F}_2.$ The lower spectrum was obtained using $785nm$ laser excitation and the top one using $514nm$ laser excitation. Briefly discuss the main difference between the spectra and suggest the underlying reason.

$[2]$