Subject: Inorganic Chemistry · Chapter: Inorganic Spectroscopy · Topic: Inorganic Spectroscopy – General · Exam: NET JUNE 2017 · Marks: 2 · Difficulty: Medium
Mössbauer spectrum of complex $[\mathrm{Fe(1,10\text{-}phenanthroline)_2(NCS)_2}]$ shows two lines at 300 K, four lines at 186 K, and again two lines at 77 K. This can be attributed to
\[ \begin{array}{l} \text{A. change in the coordination mode of NCS} \\ \text{B. change in the spin-state of iron} \\ \text{C. cis-trans isomerisation} \\ \text{D. change in metal-ligand bond distances} \end{array} \]