EXPERIMENTAL ELECTRON-DENSITY STUDY OF 1,2,4-TRIAZOLE AT 15 K - A COMPARISON WITH AB-INITIO CALCULATIONS

Topological properties and the Laplacian function of the electron dens ity of 1,2,4-triazole have been determined from X-ray diffraction data collected at 15 K. 1,2,4-Triazole, C2H3N3, orthorhombic, space group Pbca, Z = 8, lattice parameters a = 9.717(4) Angstrom, b = 9.304(4) An gstrom and c = 6.912(4) Angstrom. The results are compared with those derived from ab initio-wavefunctions at the Hartree-Fock and MP2 level of theory. The different C-N bonds are analyzed in terms of bond topo logical parameters. The result reveals considerable aromaticity which seems to be enhanced by the strong hydrogen bonds.