Studies on the Molecular Structures of Some Cyanuric Compounds by Electron Diffraction

Abstract 1. The molecular structure of cyanuric chloride and melamine were investigated by the electron diffraction. The following values were obtained by the analysis based on D3h symmetry of the molecules: C-Nr=1.33±0.02 Å, C-Cl=1.68±0.03 Å, and ∠Nr-C-Nr=125±3° for cyanuric chloride: C-Nr=1.34±0.01 Å, C-N0=1.37±0.03 Å, and ∠NrC-Nr=123±3° for melamine assuming No-H=1.04 Å, ∠C-No-H=∠H-N0-H=120°, and the coplanarity of all atoms. 2. Simple MO calculations were applied for both molecules as well as for sym-trichlorobenzene and sym-triaminobenzene. The resulted molecular diagrams were discussed together with the data obtained in the present experiment.