Infrared spectroscopic studies of hydrogenated silicon clusters

Guiding the search for Si₂H_x species in the Circumstellar Envelope of IRC+10216

¹ Department of Chemistry, University of Hawai'i at Manoa, Honolulu, HI 96822, USA e-mail: kaiser@gold.chem.hawaii.edu
² Department of Physics and Astronomy, The Open University, Milton Keynes MK7 6AA, UK
³ Department of Chemistry, Rikkyo University, 3-34-1 Nishi-ikebukuro, Tokyo 171-8501, Japan

Received: 19 February 2004
Accepted: 8 November 2004

Abstract

Silicon-bearing species Si₂H_x ( 1–6) are probable candidates in the circumstellar envelope of IRC+10216. We have observed several fundamentals of new silicon-containing radicals Si₂H₃ and Si₂H₅ in addition to the well-known Si₂H₄ and Si₂H₆ species from infrared spectroscopy in low temperature silane matrices at 10 K. Several infrared bands identify the Si₂H_x species and can be used to search for these molecules in the circumstellar envelope of IRC+10216. These infrared bands are confirmed by ab initio quantum chemical calculation as well as via corresponding infrared spectra detected for the deuterated species Si₂D_x.