title: Synthesis of the Smallest Member of the Silylketene Family: H3SiC(H)=C=O.
abstract: Exploiting photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS) combined with electronic structure calculations, it is shown that the hitherto elusive silylketene molecule (H3SiC(H)=C=O)-the isovalent counterpart of the well-known methylketene molecule-is forming via interaction of energetic electrons with low-temperature silane-carbon monoxide ices. In combination with the infrared spectroscopically detected triplet dicarbon monoxide reactant, electronic structure calculations suggest that dicarbon monoxide reacts with silane via a de facto insertion of the terminal carbon atom into a silicon-hydrogen single bond. This is followed by non-adiabatic reaction dynamics triggered by the heavy silicon atom intersystem crossing from the triplet to the singlet manifold, eventually leading to the formation of silylketene. The non-equilibrium nature of the elementary reactions within the exposed ices results in an exciting and novel chemistry which cannot be explored via traditional preparative chemistry. Since the replacement of hydrogen in silane can introduce side groups such as silyl or alkyl, the reaction of triplet dicarbon monoxide with silane represents the parent system for a previously disregarded reaction class revealing an elegant path to access the largely reactive group of silylketenes.
authors.affiliation: Department of Chemistry and W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, Hawaii, 96822, USA.|Permanent Address: Laboratory of Molecular Spectroscopy, Institute of Chemistry, Eötvös University, PO Box 32, H-1518, Budapest 112, Hungary.
authors.forename: György
authors.identifier: http://orcid.org/0000-0002-2345-1774
authors.initials: G
authors.lastname: Tarczay
authors.affiliation: Department of Chemistry and W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, Hawaii, 96822, USA.|Present address: Berlin Institute of Technology, IOAP, Hardenbergstrasse 36, 10623, Berlin, Germany.
authors.forename: Marko
authors.identifier: http://orcid.org/0000-0002-3630-9494
authors.initials: M
authors.lastname: Förstel
authors.affiliation: Department of Chemistry and W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, Hawaii, 96822, USA.
authors.forename: Sándor
authors.initials: S
authors.lastname: Góbi
authors.affiliation: Department of Chemistry and W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, Hawaii, 96822, USA.
authors.forename: Pavlo
authors.initials: P
authors.lastname: Maksyutenko
authors.affiliation: Department of Chemistry and W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, Hawaii, 96822, USA.
authors.forename: Ralf I
authors.identifier: http://orcid.org/0000-0002-7233-7206
authors.initials: RI
authors.lastname: Kaiser
keywords: VUV laser ionization time-of-light mass spectrometry; astrochemical ices; formation mechanism; reactive molecules; silicon compounds