Using molecular graphics software, we designed numerous models of C nN3 (n= 1-8). Geometry optimization and calculation on vibration frequency were carried out by the B3LYP density functional method. After comparison of structure stability, we found that the structures of ground-state CN3- and C2N3 - are bent chains with a nitrogen atom at either end, whereas when n = 3-8, the ground-state clusters show three branches, each with a nitrogen atom located at the end. When n= 5-8, the longest branch of CnN 3- is polyacetylenelike. When n = 5 or 7, the longest branch is connected to the central sp2 carbon in a nonlinear manner. The CnN3-(n= 1 -8) with an even number of carbon atoms are more stable than those with odd numbers, matching the peak pattern observed in laser-induced mass spectra of CnN 3-. The trend of such odd/even alternation is explained based on concepts of bonding characteristics, electron affinities, and incremental binding energies.
Scopus Subject Areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry