The red color of oxyhaemoglobin is mainly due to the
(a)d-d transition
(b)metal to ligand charge transfer transition
(c)ligand to metal charge transfer transition
(d)intraligand $\pi-\pi^{*}$ transition.
Answer
Answer: D ✓ checked by 4AB · confidence medium
The source book printed no answer; this one was worked out and checked — see the explanation.
Explanation
The intense red colour of oxyhaemoglobin comes from the porphyrin π→π* (Soret and Q) bands of the haem ligand, which dwarf the weak d–d transitions of low-spin Fe(II).