10.6084/M9.FIGSHARE.12947171
Mark C. Babin
Martin DeWitt
Marissa L. Weichman
Jessalyn A. DeVine
Daniel M. Neumark
High-resolution anion photoelectron spectroscopy of cryogenically cooled 4-atom silicon carbides
<p>High-resolution anion photoelectron spectra of cryogenically cooled <math><msub><mrow><mi>Si</mi></mrow><mrow><mn>3</mn></mrow></msub><mrow><mi>C</mi></mrow><mo>−</mo></math>, <math><mrow>S</mrow><mrow><msub><mrow>i</mrow><mn>2</mn></msub></mrow><msubsup><mrow>C</mrow><mn>2</mn><mo>−</mo></msubsup></math>, and <math><msubsup><mrow>SiC</mrow><mn>3</mn><mo>−</mo></msubsup></math> obtained using slow photoelectron velocity-map imaging (cryo-SEVI) are presented, providing insight into the geometries, energetics, and vibronic structure of the anionic and the neutral clusters. These spectra yield accurate vibrational frequencies for the neutral clusters. They also yield refined adiabatic detachment energies (ADEs) for the ground states of <math><msub><mrow><mi>Si</mi></mrow><mrow><mn>3</mn></mrow></msub><mrow><mi>C</mi></mrow><mo>−</mo></math> and <math><mrow>S</mrow><mrow><msub><mrow>i</mrow><mn>2</mn></msub></mrow><msubsup><mrow>C</mrow><mn>2</mn><mo>−</mo></msubsup></math> of 1.5374(6) eV and 1.9019(4) eV, respectively, while the ADE of a low-lying isomer of <math><msubsup><mrow>SiC</mrow><mn>3</mn><mo>−</mo></msubsup></math> is found to be 1.9050(7) eV. The cryo-SEVI spectra show that the ground state of <math><mrow>S</mrow><mrow><msub><mrow>i</mrow><mn>2</mn></msub></mrow><msubsup><mrow>C</mrow><mn>2</mn><mo>−</mo></msubsup></math> is a distorted trapezoid, and represent the first confirmation of the distorted trapezoid structure of <math><msub><mrow><mi>Si</mi></mrow><mrow><mn>2</mn></mrow></msub><msub><mrow><mi>C</mi></mrow><mrow><mn>2</mn></mrow></msub></math>, the only low-lying isomer of this cluster with a permanent dipole moment. Additional transitions are observed from two low-lying anion isomers: a linear structure and a rhombus. The spectrum of <math><msubsup><mrow>SiC</mrow><mn>3</mn><mo>−</mo></msubsup></math>, in combination with electronic structure calculations, suggests that the true ground state of <math><mrow><mi>Si</mi></mrow><msub><mrow><mi>C</mi></mrow><mrow><mn>3</mn></mrow></msub></math> is a ring structure with a transannular C–C bond, addressing a longstanding controversy surrounding this cluster. All three spectra exhibit Franck-Condon forbidden transitions; these are attributed to Herzberg-Teller coupling in <math><msub><mrow><mi>Si</mi></mrow><mrow><mn>3</mn></mrow></msub><mrow><mi>C</mi></mrow></math> and <math><mrow><mi>Si</mi></mrow><msub><mrow><mi>C</mi></mrow><mrow><mn>3</mn></mrow></msub></math> and autodetachment from an excited electronic state of <math><mrow>S</mrow><mrow><msub><mrow>i</mrow><mn>2</mn></msub></mrow><msubsup><mrow>C</mrow><mn>2</mn><mo>−</mo></msubsup></math>.</p>
Biochemistry
29999 Physical Sciences not elsewhere classified
Cell Biology
Neuroscience
Pharmacology
Biotechnology
39999 Chemical Sciences not elsewhere classified
Immunology
80699 Information Systems not elsewhere classified
111714 Mental Health
110309 Infectious Diseases
60506 Virology
Taylor & Francis
2020
2020-09-11
2021-03-22
Journal contribution
2589575 Bytes
10.1080/00268976.2020.1817596
CC BY 4.0