Question

Can infrared spectroscopy be used to determine whether the structure of the I3‒ ion is linear or bent? Explain your reasoning.

Answer 1

yes, the infrared spectroscopy can be used to determine the structure of I3- ions is linear or bent.

The main criteria for IR spectroscopy is that the molecule must generate dipolemoment due to stretching and bending vibration. Assymmetric stretching and bending of I3- ions generate dipole moment, which is responsible to produce vibration peak in IR spectra at different wavelength. This is due to the different value of force constant at two different geometry.