| Abstract
| - The structures, energetics, spectroscopies, and stabilities of the doublet NC2O radical are explored at densityfunctional theory and ab initio levels. Nine minimum isomers are located connected by 22 interconversiontransition states. At the CCSD(T)/6-311+G(2df)//QCISD/6-311G(d)+ZPVE level, the lowest-lying isomeris bent NCCO 1 (0.0 kcal/mol) with 2A‘ state followed by bent isomer CNCO 2 (16.7). Two isomers (1 and2) and another high-lying species CCNO 4 (99.4) with bent structure are considerably stabilized by a barrierof at least 20 kcal/mol. All of the three isomers should be experimentally or astrophysically observable. Thisresult is consistent with their indication of neutralization−reionization mass spectrometry experiments. Also,the calculated spectroscopic properties and bond distances of known NCCO 1 are consistent with recentexperimental observations and theoretical studies. The bonding natures of the isomers 1, 2, and 4 are analyzed.Their molecular properties including the heats of formation, adiabatic ionization potentials, and adiabaticelectronic affinities are calculated at the higher levels G3//B3LYP, G3(MP2)//B3LYP, QCISD, and CCSD(T) (single-point). Possible formation strategies of the isomers 1, 2, and 4 in laboratory and space are alsodiscussed in detail.
|
