Accurate computational prediction of the structural and vibrational properties of s-triazine derivatives in vacuo. A DFT approach

The well-known class of herbicides, s-triazine derivatives, are commonly used as reagents in the manufacture of resins and pharmaceuticals, and also of solvent-refined coals. Recently, triazine derivatives have been observed to form self-assembling nanostructures on metallic surfaces. In this paper, we present a study using a DFT approach for the computational prediction of the structural and vibrational properties in vacua of three s-triazine derivatives, viz., atrazine (N,N'-ethyl-isopropyl-6-chloro-1,3,5-triazine,2,4-diamine), prometryn (N,N'-diisopropyl-6-methyl-thio-1,3,5-triazine,2,4-diamine) and simetryn (N,N'-diethyl-6-methyl-thio-1,3,5-triazine,2,4-diamine). In particular we show that the employment of the Becke three-parameter Lee-Yang-Parr (B3-LYP) exchange-correlation functional using the aug-cc-pVQZ basis set provides an accurate prediction of the structural and vibrational properties of atrazine, prometryn, and simetryn.