For each of the following pairs of metal complexes, circle the one that will have the lowest CO stretching frequency. Clearly discuss your reasoning for your choice. a) [Co(CO) 4 ]- or [Fe(CO)4 ]2 – b) CpRe(CO) 3 or Cp*Mn(PEt3 )(CO) 2 (Cp* = C 5 Me5– )
