Matrix isolation spectroscopy study of iron reactivity towards PAHs.

The hypothesis of organometallic chemistry between polycyclic aromatic hydr ocarbons (PAHs) and metals in the interstellar medium (ISM) has been recent ly proposed to contribute both to the unidentified interstellar infrared (U IR) emission and to the depletion of transition metals in the ISM. Since te mperature and pressure conditions of the ISM can be easily simulated by mat rix isolation techniques, we have undertaken the preparation of such specie s through cocondensation reactions of metal atoms (iron) with some PAHs (py rene, coronene) in low temperature argon and dinitrogen matrices. The ident ification of species is achieved by means of FTIR and W-visible spectroscop ies. First results show that a weak reactivity occurs between neutral speci es at 10K: pi-complexes, hydrogen-bonded compounds, and one hydride species have been observed. (C) 1999 Elsevier Science Ltd. All rights reserved.