Stability and aromaticity of nitrogen rings. N3 +, N4, and N6
American Chemical Society Journal , Volume 96 - Issue 15 p. 4753- 4760
An ab initio calculation is performed for the structures N3 +, N4, and N6 using single-ζ and double-ζ basis sets of STO's. A secondary minimum exists for N3 + in its cyclic form which lies above the energy of the linear symmetric and linear asymmetric geometries. N4 in square planar, rectangular, and tetrahedral geometries is found to lie far above the energy of two nitrogen molecules. N6 is somewhat stabilized relative to N4. The energies and structures are discussed in the context of aromaticity. Single-ζ and double-ζ results differ significantly, with the single-ζ calculations apparently overemphasizing the stability of small rings.