Organometallic Chemistry

Untangling the formation of organo silicon and germanium molecules at low temperature presents an important means to understand the chemical processing of circumstellar envelopes, of molecular clouds, and of planetary atmospheres of Jupiter and Saturn. These processes have also strong ties to semiconductor device manufacturing and non-traditional organic synthesis. We initiated a Si-C, Si-Si, and Ge-Ge bond coupling by interaction of the silane,  methane, and germane molecules by electron irradiation to form the silyl, methyl, and germyl radicals followed by recombination of the radicals to form 1,2-disila-ethane (disilane), 1-sila-ethane, and digermane. These primary reaction products have been observed via infrared spectroscopy and are degraded sequentially to hydrogen-deficient radicals and clusters. For example, for the first time, we identified transitions of the 1,2-disila-vinyl and 1,2-disila-ethyl radicals in low temperature matrices. These assignments have been confirmed with perdeuterated reactants. Similar radicals were identified in electron irradiated methane-silane and germane ice samples at 10 K.

1. D. Sillars, C.J. Bennett, Y. Osamura, R.I. Kaiser, Infrared spectroscopic detection of the disilenyl (Si₂H₃) and d3-disilenyl (Si₂D₃) radicals in silane and d4-silane matrices, Chem. Phys. Lett. 392, 541-548 (2004). (PDF file)

2. D. Sillars, C.J. Bennett, Y. Osamura, R.I. Kaiser, First infrared spectroscopic characterization of the disilyl (Si₂H₅) and d5-disilyl (Si₂D₅) radicals in low temperature silane matrices, Chem. Phys. 305, 141-153 (2004). (PDF file)

3. C.J. Bennett, D. Sillars, Y. Osamura, R.I. Kaiser, Infrared spectroscopic identification of the methylsilylidyne (SiCH₃, X²A") and the silenyl (H₂CSiH, X²A') radicals in methane-silane matrices, Chem. Phys. Lett. 404, 327-335 (2005).  (PDF file)

4. D.S. Sillars, C.J. Bennett, Y. Osamura, R.I. Kaiser, Infrared spectroscopic detection of  the methylsilyl (CH₃SiH₂, X²A') and the silylmethyl (CH₂SiH₃, X²A') radicals and their partially deute­rated counterparts in low temperature matrices,  Chem. Phys. 315, 41-52 (2005).  (PDF file)

5. R.I. Kaiser, Y. Osamura, Laboratory Studies on the Infrared Absorptions of Hydrogenated Carbon-Silicon Clusters: Directing the Identification of Organometallic SiCH_x Species toward IRC+10216, ApJ 630, 1217-1222 (2005). (PDF file)

6. W. Carrier, W. Zheng, Y. Osamura, R.I. Kaiser, First infrared spectroscopic characterization of the digermyl  (Ge₂H₅) and d5-digermyl (Ge₂D₅) radicals in low temperature germane matrices, Chemical Physics 325, 499–508 (2006) (PDF file)

7. W. Carrier, W. Zheng, Y. Osamura, R.I. Kaiser, Infrared spectroscopic identification of digermene, Ge₂H₄ (X¹A_g), and of the  digermenyl radical, Ge₂H₃(X²A”), together with their deuterated counterparts in low temperature germane matrices.  Chem. Phys 330, 275–286 (2006).(PDF file)

8. W. Carrier, W. Zheng, Y. Osamura, R.I. Kaiser, Laboratory Investigations on the Infrared Absorptions of Germanium-Bearing Molecules-- directing the identification of organo-Germanium molecules in the Atmospheres of Jupiter and Saturn, ApJ, 654, 687-692 (2006)..(PDF file)