DFT and Experimental Study of the Host–Guest Interactions Effect on the Structure, Properties, and Electro-Catalytic Activities of N₂O₂–Ni(II) Schiff-Base Complexes Incorporated into Zeolite

Abstract

Ni II -(N,N′-bis(2,4-dihydroxyacetophenone)-2,2-dimethylpropandiimine (Ni II {salnptn(4-OH) 2 }) complex has been encapsulated within the supercage of zeolite-NaY by reacting Ni 2+ -exchanged NaY with the flexible Schiff-base ligand that diffuses into the cavities. The encapsulated complex is characterized by EDX, scanning electron microscopy, powder X-ray diffraction, FT-IR, and cyclic voltammetry studies. Density functional calculation is being carried out on both the free nickel Schiff-base complex and that encapsulated in NaY zeolite to investigate changes in structural parameters, energies of the HOMO and LUMO, and absolute hardness and softness. Electrochemical properties of the NaY zeoliteencapsulated Ni II {salnptn(4-OH) 2 }-modified carbon paste electrode and the Pt electrode modified with the film derived from the electro-polymerization of this complex are studied. These modified electrodes show electro-catalytic activity toward the oxidation of methanol and other short-chain aliphatic alcohols. The results show two different oxidation mechanisms on the surface of these modified electrodes. The effect of some parameters such as potential scan rate, concentration of alcohols, and the corresponding rate laws have been derived. Furthermore, the rate constants for the catalytic reaction (k′) of alcohols are obtained.

Theoretical and experimental studies on three new coordination complexes of Co(II), Ni(II), and Cu(II) with 2,4-dichloro-6-{(E)-[(5-chloro-2 sulfanylphenyl)imino]methyl}phenol Schiff base ligand

“…The remaining two S11 and S30 atoms occupy the up and down positions perpendicular to the plane. The Ni(II) and Cu (II) complexes occupy a square planar geometry with little distortion around the metal center [25,38,42]. In Ni(II) complex; three positions of plane are occupied by ligand moiety through azomethine nitrogen, phenolic oxygen and through sulfur of thiol moiety around the metal center while the remaining fourth position is occupied by one molecule of coordinated water.…”

“…In the Electronic supplementary material The online version of this article (doi:10.1007/s00894-015-2805-z) contains supplementary material, which is available to authorized users. absence of an X-ray crystal structure data, density functional theory (DFT) provides an alternative option for the prediction of fairly accurate three dimensional structures of the compounds [37][38][39]. Although the field of metal complexes has been explored tremendously, however, the advanced awareness is still sought to target the specific applications.…”

Computational studies on heterogenization of homogeneous catalyst of iron(III), nickel(II) and copper(II) N,N′-disalicylidene-1,2-phenylenediamine complex

“…The information we could able to extract from the existing physicochemical characterization techniques is limited. In general, zeolite encapsulated metal complexes are characterized to address the following aspects; the composition of metal complexes residing in the zeolite cage; the framework of zeolite is preserved after the encapsulation of metal complexes; thermal stability of the encapsulated metal complexes as compared to neat metal complexes and neat zeolite; morphological changes associated with encapsulation process; effect of molecular confinement on the conformational geometry and the mobility of the complexes inside the zeolite cage; internal versus external confinement and the distribution of guest compounds in zeolite host; nature of the metal complex formed in zeolite cavity compared to neat metal complex and neat zeolite; the effect of host-guest interactions on the structure of metal complex [22][23][24].…”

“…Furthermore, it is not possible to have the information about the influence of the zeolite matrix on the structure and electronic properties of the enclosure compounds. However, a theoretical investigation of the physical and chemical properties based quantum chemical calculations has provided a better understanding of the properties of neat metal complex and zeolite encapsulated metal complexes and the science behind their catalytic activity and stability [22][23][24][25][26]. Quantum chemical calculation based on density functional theory (DFT) is one of the operational tools in explaining chemical reactivity of the catalyst [27][28][29][30][31].…”

Electrocatalytic reduction of PhCH2Br on a Ag–Y zeolite modified electrode

“…Among the investigations, both homogeneous 1-3 and heterogeneous 4-8 catalytic methods have been tried due to the negative reduction potential of organic halides. 19,20 However, no paper is concerning the electrocatalytic reduction and carboxylation of organic halide on ZMEs, as far as we know. 14,15 Zeolites are stable crystalline aluminosilicates with ordered micropores or/and nanosized cages, which makes them good supports for nanoscale metal or metal oxides.…”