Synthesis of fac-[FeII(CN)(CO)3I2]− and chemistry of the fac-[FeII(CN)x(CO)3I(3 − x)]− series (x = 1–3)

Whole series of fac-[FeII(CN)x(CO)3I(3 − x)]− (x = 1–3) generated by stepwise replacement of iodide from fac-[FeII(CO)3I3]− by cyanide were isolated and structurally characterized. The infrared trend of this series demonstrates the effect of the electronic properties of ligands on the coordinated CO stretching frequencies.