Cu(II) and Co(II) Schiff‐Base Complexes Immobilized on Layered Double Hydroxide: Synthesis, Characterizations, DFT Calculations and Catalytic Activity

Abstract

In this study, we are reporting the synthesis, characterization, theoretical studies, and catalytic activity of Cu(II), and Co(II) Schiff base complexes immobilized on layered double hydroxide abbreviated as LDH‐[NAPABA‐M] {where M=Cu(II), and Co(II)}. The Schiff base ligand (E)‐4‐((2‐hydroxynaphthalen‐1‐yl)methyleneamino)benzoic acid have been synthesized from the condensation of 2‐hydroxy‐1‐naphthaldehyde and 4‐amino benzoic acid. The complexes were characterized using Inductively coupled plasma‐Atomic emission spectrometry (ICP‐ AES), X‐Ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X‐Ray (EDX), Fourier transform infrared (FTIR), Electron paramagnetic resonance (EPR) spectroscopy, Thermogravimetric analysis (TGA) etc. and the geometry of the ligand has been calculated using Density Functional Theory (DFT) calculations at the B3LYP/6‐31G level of theory. The catalytic activity of synthesized catalysts was tested for toluene oxidation with tert‐butyl hydroperoxide under solvent‐free conditions. The LDH‐[NAPABA‐Cu(II)] catalyst was recycled up to seven cycles. Hot filtration experiments demonstrate that the catalyst was heterogeneous in nature and stable.

Coherent design of chromium oxide nanoparticles immobilized on layered double hydroxide as competent nanocatalyst for the oxidation of cyclohexane to KA oil

“…LDHs have unique properties such as adjustable acidity, basicity, good layer expansion properties, chemical inertness, excellent surface area, and gallery anions between the layers. These properties make LDHs an excellent choice as supports for the preparation of heterogeneous catalysts for catalysis [10][11][12]. As a typical hydroxide support, active metal species can be supported on LDHs using traditional methods such as impregnation [13], precipitation-deposition [14], or by utilizing electrostatic interactions to introduce metal complexes into the interlayers of LDHs [15,16].…”

Fabrication and Characterization of Cu Nanoparticles Dispersed on ZnAl-Layered Double Hydroxide Nanocatalysts for the Oxidation of Cyclohexane

“…We have recently synthesized transition metal Schiff base complexes based on LDHs as heterogeneous catalysts and tested their catalytic activity for oxidation of toluene. 29,30 In this paper, we have adopted a simple chemical reduction approach to synthesize CuNPs@LDH that may function as a heterogeneous nanocatalyst for the selective oxidation of cyclohexane using tert-butyl hydroxide as an oxidant. To improve the reaction conditions for obtaining optimum conversion of cyclohexane and selectivity of KA oil, we have studied various parameters such as the influence of different oxidants, influence of the TBHP to cyclohexane molar ratio, influence of the catalyst amount, influence of temperature, and influence of time.…”

“…Furthermore, uniform dispersion of M­(II) and M­(III) cations in the LDH layers, as well as anion-preferred orientations in the interlayer, is a useful feature for using LDH as precursors for the fabrication of stably supported catalysts. We have recently synthesized transition metal Schiff base complexes based on LDHs as heterogeneous catalysts and tested their catalytic activity for oxidation of toluene. , …”

“…We have recently synthesized transition metal Schiff base complexes based on LDHs as heterogeneous catalysts and tested their catalytic activity for oxidation of toluene. 29 , 30 …”