NLO Activity in some non-conjugated 3D triazine derivatives: a non-centrosymmetric crystal through conformational flexibility

Four derivatives of 2,4,6-tris(benzyloxy)-1,3,5-triazine are synthesized and detailed computational and non-linear optical investigations are carried out. Computations indicate four conformations with different energies in all the systems in the gas phase; and the individual dipole moments are also of different magnitude. HRS measurements of these molecules in solution reveal moderately large β values; structure–property relations are analyzed through computations. These molecules have one added advantage of nearly 100% optical transmission through the visible range, due to the non-conjugated structure. Molecule 1 [2,4,6-tris(benzyloxy)-1,3,5-triazine] crystallizes in a non-centrosymmetric space group by adopting the conformation with the lowest dipole moment but not the lowest energy. It also shows SHG activity in the solid state.