A Gaussian-2 study of isomeric C{sub 2}H{sub 2}N and C{sub 2}H{sub 2}N{sup +}

Journal Article · Thu Apr 29 04:00:00 EDT 1999 · Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory

DOI:https://doi.org/10.1021/jp984540i· OSTI ID:351594

Lau, K C; Li, W K ^[1]; Ng, C Y ^[2]; Chiu, S W ^[3]

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1. Chinese Univ. of Hong Kong, Shatin (Hong Kong). Dept. of Chemistry
2. Ames Lab., IA (United States)
3. Univ. of Illinois, Urbana, IL (United States). National Center for Supercomputing Applications

The structures and energetics of the C{sub 2}H{sub 2}N and C{sub 2}H{sub 2}N{sup +} isomers have been investigated using a modified Gaussian-2 (G2) method, which takes into account the energy correction due to spin contamination. At the QCISD(Full)/6-31G(d) level, C{sub 2}H{sub 2}N may exist as 12 stable isomers. In the order of decreasing stabilities, they are CH{sub 2}CN (1), CH{sub 2}NC (2), CHCNH (3), c-CH{sub 2}CN (4), c-NCHCH (5), CHNCH (6), NH{sub 2}CC (7), NHCHC (9), c-NHCHC (10), cis-CHCHN (12), cis-CHNHC (13), and trans-CHNHC (14). On the other hand, there are seven C{sub 2}H{sub 2}N{sup +} isomers. In the order of decreasing stabilities, they are c-NCHCH{sup +} (5{sup +}), CH{sub 2}CN{sup +} (1{sup +}), CH{sub 2}NC{sup +} (2{sup +}), CHCNH{sup +} (3{sup +}), CHNCH{sup +} (6{sup +}), c-NHCHC{sup +} (10{sup +}), and NH{sub 2}CC{sup +} (7{sup +}). The G2 result for the ionization energy of 1 and the {Delta}H{degree}{sub f298} values of 1 and 1{sup +} are in good agreement with the available experimental data. However, the G2 results for radicals 2 and 5 as well as cations 2{sup +} and 5{sup +} do not agree with the experimental data in the literature. This calls for a reexamination of the experimental results. Furthermore, in a recent study of the reaction between nitrogen atom and vinyl radical, a C{sub 2}H{sub 2}N radical was formed with an ionization energy <9.64 eV. On the basis of the calculations and known reactivity of the reactants, it is concluded that the unidentified isomer is likely to be 2.

• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 351594
• Journal Information: Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory, Journal Name: Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory Journal Issue: 17 Vol. 103; ISSN 1089-5639; ISSN JPCAFH
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
CALCULATION METHODS
CATIONS
CYANIDES
FORMATION HEAT
GAUSSIAN PROCESSES
ISOMERS
METHYL RADICALS
MOLECULAR STRUCTURE