Question

Draw a qualitatively energy-level diagram showing d-orbital splitting in the octahedral environment. Predict the number of unpaired electrons in the complex [Fe(CN)₆]^4⊕. Is the complex diamagnetic or paramagnetic? Is it coloured? Explain.

Answer 1

(A) r-orbital splitting in the octahedral environment :

(B) [Fe (CN)₆]^4- is an octahedral complex.

(C) Since CN^- is a strong ligand, there is pairing of electrons and the complex is diamagnetic.

(D) The complex exists as lemon yellow crystals.

(In the complex all electrons in t_2g are paired and requires high radiation energy for excitation.)