NEW THEORETICAL CALCULATIONS ON ISOMERISM OF FOR TRIPODS BASED ON THE N-C-PYRAZOLYL MOTIF

Abstract

New theoretical studies of two isomeric series of tripods based on the N-C-pyrazolyl motif {N,N-bis(3,5-dimethyl-pyrazol-1-ylmethyl)-N,N-dimethyl-p-phenylenediamine 1 ; N,Nbis[(1,5-di-methylpyrazol-3-yl)methyl]-N,N-dimethyl-p-phenylenediamine 2 ; N,N-bis(3,5- dimethyl-pyra -zol-1-ylmethyl)benzylamine 3 and N,N-bis[(1,5-dimethylpyrazol-3- yl)methyl]benzylamine 4} were investigated. The chemical reactivity descriptors were computed using density functional theory method (B3LYP) with 6-31 G* and 6-311+G(2d,p) as basis sets. The distributions of frontier molecular orbital’s, softness and enthalpies remain unchanged according to the junction mode between the aniline N-atom and the pyrazole rings. In contrary, the relative stability, frontier molecular orbital energies, molecular electrostatic potential surfaces, electric dipole moments, ionization energies, chemical hardness, electron affinities, electronegativities, electronic chemical potentials, global electrophilicity indexes, entropies, heat capacities and hyperpolarisabilities were influenced by the nature of junctions. Also, tripods presenting N-C-N junctions are more stabilized towards chemical reaction than their isomers. Otherwise, these compounds are suitable to be used as non-linear optical material with an advantage for the tripods with N-C-N junctions.