Two new Schiff-base modified vanadium complexes with third-order NLO properties

Two new Schiff-base modified vanadium complexes, [VIVO(C7 H5O)2(N2C6H10)] (1) and [VVO2(C7H5O)(N2C6H12)] (2), were synthesized under hydrothermal conditions, in which salicylaldehyde and cyclohexanediamine were used directly to form Schiff-base ligands during the reactions. The structures of 1 and 2 were characterized by EA, FT-IR, UV-vis, SCXRD and PXRD, EPR spectroscopy and magnetic susceptibility measurement. Due to the good optical activity of Schiff-base ligands and the existence of conjugated benzene rings in 1 and 2, the delocalized electronic effects between Schiff-base ligands and vanadium can be improved. Therefore, the third-order non-linear optical (NLO) properties of these complexes were investigated. The results of the open aperture Z-scan tests show that the two-photon absorption (TPA) cross-sections (σ) of the complexes are 1033 and 1041GM, respectively, which indicated that they both have potential applications as NLO materials.