TRIS(PYRAZOL-1-YL)-S-TRIAZINE (TPT) - X-RAY CRYSTALLOGRAPHIC, COMPUTATIONAL, AND GAS-PHASE ELECTRON-DIFFRACTION STUDIES

The conformation of the TPT molecule has been analyzed using experimental and computational techniques. The solid-state molecular structure shows similar conformational features to those in the 2-pyrimidine and phenyl derivatives although a different pattern of bond angles in the triazine ring was observed. The AMI calculations predicted two conformations of comparable stability (DELTAE = 1.8 kcal/mol) differing in the orientation of one pyrazole ring. While the minimum energy conformation corresponds to a model displaying C3h symmetry (phi1 = phi2 = phi3 = 0-degrees), the other minimum (phi1 = phi2 = 0-degrees, phi3 = 180-degrees) is close to that observed in the solid state. The electron diffraction results are consistent with a planar or nearly planar conformation in agreement with the preceding studies.