Collect. Czech. Chem. Commun. 1979, 44, 3441-3451

Structure, energy characteristics, and electronic spectra of two isoelectronic radicals, HCN2 and H2C2N: A theoretical study

Zdeněk Slaninaa and Zbigniew R. Grabowskib

a J. Heyrovský Institute of Physical Chemistry and Electrochemistry, Czechoslovak Academy of Sciences, 121 38 Prague 2
b Institute of Physical Chemistry, Polish Academy of Sciences, 012 24 Warsaw, Poland


The molecular structure of the title radicals was investigated by means of the CNDO/2 and MINDO/2 methods. Calculations suggest that both radicals might exist in two isomeric forms (cyclic and open). Thermodynamic characteristics of the H2C2N isomerization were calculated. Electronic spectra of both radicals were obtained using limited configuration interaction treatment based on the Del Bene and Jaffe SCF method. Calculation and observation agree satisfactorily for the HCN2 radical. A comment is made on the role of isomerism when electronic spectra are studied theoretically.