| Autor: |
Stanton JF; Institute for Theoretical Chemistry, Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, USA., Garand E, Kim J, Yacovitch TI, Hock C, Case AS, Miller EM, Lu YJ, Vogelhuber KM, Wren SW, Ichino T, Maier JP, McMahon RJ, Osborn DL, Neumark DM, Lineberger WC |
| Jazyk: |
angličtina |
| Zdroj: |
The Journal of chemical physics [J Chem Phys] 2012 Apr 07; Vol. 136 (13), pp. 134312. |
| DOI: |
10.1063/1.3696896 |
| Abstrakt: |
A joint experimental-theoretical study has been carried out on electronic states of propadienylidene (H(2)CCC), using results from negative-ion photoelectron spectroscopy. In addition to the previously characterized X(1)A(1) electronic state, spectroscopic features are observed that belong to five additional states: the low-lying ã(3)B(1) and b(3)A(2) states, as well as two excited singlets, Ã(1)A(2) and B(1)B(1), and a higher-lying triplet, c(3)A(1). Term energies (T(0), in cm(-1)) for the excited states obtained from the data are: 10,354±11 (ã(3)B(1)); 11,950±30 (b(3)A(2)); 20,943±11 (c(3)A(1)); and 13,677±11 (Ã(1)A(2)). Strong vibronic coupling affects the Ã(1)A(2) and B(1)B(1) states as well as ã(3)B(1) and b(3)A(2) and has profound effects on the spectrum. As a result, only a weak, broadened band is observed in the energy region where the origin of the B(1)B(1) state is expected. The assignments here are supported by high-level coupled-cluster calculations and spectral simulations based on a vibronic coupling Hamiltonian. A result of astrophysical interest is that the present study supports the idea that a broad absorption band found at 5450 Å by cavity ringdown spectroscopy (and coincident with a diffuse interstellar band) is carried by the B(1)B(1) state of H(2)CCC. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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