The expected number of co bands in the IR spectra of fac-$\left[\mathrm{Mo}\left(\mathrm{PPh}_{3}\right)_{2}(\mathrm{CO})_{3}\right]$ and trans-$\left[\mathrm{Mo}(\mathrm{PPh}_3)_2(\mathrm{CO})_4\right]$ are, respectively
(a)one and one
(b)Two and two
(c)two and one
(d)three and one
Answer
Answer: C ✓ checked by 4AB · confidence high
Explanation
fac-M(CO)₃L₃ (C₃v) shows two ν(CO) bands; trans-M(CO)₄L₂ (D₄h) shows one (E_u) (c).