A QUANTUM-CHEMICAL INVESTIGATION ON 3,4'BI(4H-1,2,4-TRIAZOLE)

The conformational analysis of 3,4'-bi(4H-1,2,4-triazole) molecule has been performed using the semiempirical methods MNDO, AM1 and PM3, and the stable conformations, the rotational barriers and geometric param eters have been determined. The total energies, heats of formation, di pole moments, ionization potentials, full atomic charges, energies of frontier molecular orbitals (E(HOMO) and E(LUMO)) and electron densiti es have been calculated and discussed. In order to determine the orien tation centers of proton attacks at the 3,3'-bitriazole system, the mo lecular electrostatic potential (MESP) of the molecule has been also c alculated. The conformational analyses of mono- and diprotonated speci es have also been performed by AM1 aand PM3 routes and their stable co nformations determined. The proton affinity for the different nitrogen s of the 3,4'-bitriazole molecule has been calculated using AM1 and PM 3 methods and more basic centers have been determined. Furthermore, th e complex formation ability of the molecule with metal cations is also discussed. The electronic properties of the complexes formed by Mg2and Fe2+ ions have been investigated using PM3 and ZINDO/1 methods, an d the stabilities of these complexes are discussed.