Astrophys. J., 871, 255-255 (2019/February-1)
Theoretical characterization of C3H and C5H and their anions.
BENNEDJAI S.C., HAMMOUTENE D. and SENENT M.L.
Abstract (from CDS):
Highly correlated ab initio calculations are employed for the structural and spectroscopic characterization of small odd chains of type C2n+1H, considering neutral forms, cations, and giving special attention to the anions. This work confirms the stability of the linear carbon chains and carbon clusters containing three-body rings. The smallest species, C3H, displays three stable structures, whereas C5H possesses at least 8 neutral isomers and 11 and 10 isomers with a negative or a positive charge. The equilibrium geometries, which can be candidates for laboratory and astrophysical detection, are studied using the RCCSD(T)-F12 and MRCI/CASSCF levels of theory, specifying properties for various electronic states. Four different stable isomers are confirmed for the C5H– anion. They are two rings and two chains, all showing singlet ground electronic states. The viability of the triplet linear form of C5H– (C_∞v_(X3Σ–)) postulated in previous works, is not confirmed because it appears to be really dependent on the electron correlation energy denoting instability. A quasi-linear singlet (Cs (X1A')) represents a secondary minimum. Electronic state crossing occurs close to the linear structure where spin-orbit effects are negligible. The most stable structure of C5H– is a three-carbon cycle in which rotational constants have been determined to be A0 = 35479.86 MHz, B0 = 3618.29 MHz, and C0 = 3280.10 MHz. Its dipole moment is relatively large (6.4086 D).
© 2019. The American Astronomical Society. All rights reserved.
astrochemistry - catalogs - ISM: abundances - ISM: molecules - molecular data
View the reference in ADS
To bookmark this query, right click on this link: simbad:2019ApJ...871..255B and select 'bookmark this link' or equivalent in the popup menu