Photoelectron spectroscopic study of iron–benzene cluster anions

Iron–benzene cluster anions, Fe n Bz m - (n = 1–7, m = 1–4), were generated via laser vaporization and studied using mass spectrometry, anion photoelectron spectroscopy and in one case by density functional theory. Based on these studies, we propose that Fe 1 Bz 1 - and Fe1Bz1 as well as Fe 2 Bz 1 - and Fe2Bz1 exhibit half-sandwich structures, that Fe 1 Bz 2 - and Fe1Bz2, Fe 2 Bz 2 - and Fe2Bz2, as well as Fe3Bz2 and Fe4Bz2 are sandwich structures, and that Fe 2 Bz 3 - and Fe2Bz3 and larger species form ‘rice-ball’ structures which in each case consist of benzene molecules surrounding an iron cluster core.