Electronic states and stability of GeC2N radical

Electronic states of the GeC2N radical are explored at various theoretical levels including complete active space multi-configuration self-consistent field followed by complete active space perturbation computations. Ten minimal energy isomers and 10 interconversion transition states are found. The thermodynamically most stable isomer is a linear form GeCCN 1 which is qualitatively described as a resonance hybrid of ∣GeCCN∣, ∣GeC-CN∣, and ∣GeCCN∣ forms, with the second one contributing to a greater extent suggestive of a radical adduct between GeC and CN. The second low-lying linear isomer GeCNC 2 (21.9 kcal/mol) has resonating structures ∣GeC-NC∣, ∣GeCNC∣, and ∣GeCN–C∣.