Study on iron–sulfur cluster in gas phase: electronic structure and reactivity

In gas phase, electronic and geometric properties of iron–sulfur cluster (FenSm, n=1–8, m=2–6) have been investigated using photoelectron spectroscopy (PES) of their anions and a chemical probe method for their cations. The electron affinities of FenSm greatly change at the composition of n=m, and the reactivity of FenSm+ toward NH3 and C2H2 is enhanced around equally mixed compositions. These results show that the FenSm clusters produced in gas phase seemingly take the structure having alternate bonds between Fe and S atoms, likewise that of an active site of iron–sulfur proteins.