DFT investigation of 1,1'-disubstituted-5,5'-azotetrazoles:a study of functional group effect

The idea behind most stable cis and trans configurations of an azo compound is photoisomerization of it under irradiation when non-polar trans configuration can be photoisomerized into the polar cis configuration. In the present study, the density functional theory (DFT) method with B3LYP exchange correlation corrected functional and the 6-311++G(d,p) basis set has been carried out to investigate the isomerization effect on the stability, reactivity and structural properties of 1,1'- disubstituted-5,5'-azotetrazoles. All computations were performed at 293.15 K and 1 atmosphere in gas phase. From our calculations, it is obtained that the trans configurations of all molecules are more stable than cis. Also, the dipole moment, chemical hardness (ƞ), chemical potential (μ), electronegativity (χ) and electrophilicity index (ω) were calculated for all structures. The data shows that the stability oftrans and cis configurations have direct and indirect correlation with reactivity, respectively. The results also indicate that the trans and cis configurations of compounds have planar and non-planar structures, respectively.