The UV–visible spectrum of the octahedral complex [Ni(NH₂CH₂CH₂NH₂)₃]²⁺ is shown below.

(a) Given that ethylenediamine ligand, NH₂CH₂CH₂NH₂, is a neutral bidentate ligand (both nitrogen atoms coordinate to the metal), determine the electron configuration of the nickel ion.

(b) Use a correlation diagram to assign each of the three d-to-d transitions labeled as 1, 2, and 3 below.

(c) What color would you predict for a solution of this complex ion from the spectrum below?

(d) Compare these transitions to those observed for [Ni(H₂O)₆]²⁺ (Table 7.5) and determine which complex ion has a larger Δ_oct.

Table 7.5

Transcribed Image Text:

molar extinction coefficient, 00 N 3 2 1 W 200 300 400 500 600 700 800 900 1000 1100 1200 wavelength (nm)