Gemini surfactant-stabilized Pd nanoparticles: Synthesis, characterization, and catalytic application in the reduction and reductive acetylation in the water solvent

Abstract

A series of Gemini surfactants (GSs) were prepared by reacting alkyl bromides with N,N,N′,N′-tetramethyl ethylenediamine. Various alkyl bromides used in for the preparation of GSs are 1,3-dibromo ethane, 1,3-dibromoethane, 1-Bromohexane, 1-Bromooctane, 1-Bromooctadecane and 1-Bromooctadodecane. Different solvents and temperatures were investigated for the formation of gels of prepared GSs. Among all, 1-Bromooctane, 1-Bromooctadecane-derived GSs formed organogels. Thus, synthesized long-chain organogels have been used to stabilize Pd NPs. The Pd NPs formation initially confirmed through Ultraviolet-visible, Scanning Electron Microscopy, and Atomic Force Micrograph studies. Later Fourier Tansform Infra Red, Thermo Gravimetric Analysis, and Zeta potential studies were also carried out to understand their properties extensively. The Pd NPs stabilized by GSs have been identified as a potential catalyst in the reductive N-acetylation of nitroaromatics at room temperature. The N-acetylated products were obtained in good yields in an aqueous medium. In addition, the potentiality of our catalyst has been also evaluated in the reduction of nitroaromatics in an aqueous medium, which is a green protocol. Further, the semi-empirical geometry optimizations of active GS gel confirmed the dihedral angle of 59° in between the two octyl moieties calculated from computational studies. The rheological properties such as amplitude sweeping, viscosity shear profile of the gel have also been studied. © 2023 John Wiley & Sons Ltd.