TRIAZENE PROTON AFFINITIES - A COMPARISON BETWEEN DENSITY-FUNCTIONAL,HARTREE-FOCK, AND POST-HARTREE-FOCK METHODS

The consistency of three density functional computational implementati ons (DMol, DGauss, and deMon) are compared with high-level Hartree-Foc k and Moller-Plesset (MP) calculations for triazene (HN=NNH2) and form yl triazene (HN=NNHCOH). Proton affinities on all electronegative site s are investigated as well as the geometries of the neutral and proton ated species. Density functional calculations employing the nonlocal g radient corrections show agreement with MP calculations for both proto n affinities and geometries of neutral and protonated triazenes. Local spin density approximation DMol calculations using numerical basis se ts must employ an extended basis to agree with other density functiona l codes using analytic Gaussian basis sets. The lowest energy conforma tion of triazene was found to be nonplanar; however, the degree of non planarity, as well as some bond lengths, is dependent on the basis set , electron correlation treatment, and methods used for the calculation . (C) 1994 by John Wiley and Sons, Inc.