Synthesis and Characterization of Graphene Based Hybrid Ligands and Their Metal Complexes: Investigation of Chemosensor and Catalytic Properties

Abstract

It has been synthesized the graphene oxide-based hybrid ligands and their Cu(II), Co(II) and Ni(II) complexes. Firstly, GO was reacted with 3-(trimethoxysilyl)propylamine in ethanol and the obtained structure was treated with 2,6-diformyl-4-bromophenol and 2,6-diformyl-4-tert-butylphenol in order to obtain the hybrid ligands HL1 and HL2. The synthesized hybrid ligands and their metal complexes have been and characterized by using FTIR, UV–vis., XRD, EDX, SEM, TEM, cyclic voltammetry, TG/DTA and ICP-OES techniques. Catalytic activities of Cu(II), Co(II) and Ni(II) complexes of the synthesized ligands have been investigated in the oxidation of 2-methyl naphthalene (2MN) to 2-methyl-1,4-naphthoquinone (vitamin K3). The chemosensing behaviours of the hybrid ligands were also researched by using UV–vis. technique upon addition of various metal ions such as Na(I), K(I), Cd(II), Co(II), Cu(II), Hg(II), Ni(II), Zn(II), Al(III), Cr(III), Fe(III), and Mn(II) in (1:5 V) ratio in MeOH. The UV–vis. spectra of free hybrid materials show one absorption band at 257 nm possibly due to π–π* transitions in hybrid ligands. While added the metal cations on the ligand dispersions as Cu(II) and Fe(III) (0.1 mM) (1:5 V) ratios in MeOH, a new absorption bands were appeared at different regions in 275–325, 300–375 nm, respectively, because of the complexation between the hybrid materials and the metal ions.