(Solved): Isocyanides \( (\mathrm{RN} \equiv \mathrm{C}) \) are isoelectronic with carb ...

???????

Isocyanides \( (\mathrm{RN} \equiv \mathrm{C}) \) are isoelectronic with carbon monoxide, and form stable complexes with low valent metal ions. However, isocyanides are stronger \( \sigma \)-donors and weaker \( \pi \)-acceptors. The following table contains IR stretching frequencies of carbon monoxide (CO), tert-butyl isocyanide (BuNC) and their complexes with Mo(0). (a) Provide a chemical structure for mer-Mo(CO) \( )_{3}(\mathrm{BuNC})_{3} \) (b) Explain why CO stretching frequencies generally decrease going down the listed series of Mo complexes. (c) Explain why BuNC stretching frequencies generally decrease going down the listed series of Mo complexes.