Influence of Zeolite Framework on the Structure, Properties, and Reactivity of Cobalt Phenanthroline Complex: A Combined Experimental and Computational Study

Abstract

Bis(1,10-phenanthroline) cobalt(II) complexes have been encapsulated within the supercage of zeoliteÀNaY by reacting Co 2þ exchanged NaY with the flexible phenanthroline ligand that diffuses into the cavities. The hybrid material obtained has been characterized by elemental analysis, SEM, powder XRD, FTIR, UVÀvis, cyclic voltammetry, and EPR techniques. The difference in UVÀvis spectra and redox properties between the neat and intrazeolite complexes suggest that the metal complex undergoes distortion inside the zeolite matrix and this result is being supported by density functional study where we found a change in structural parameters, position of the HOMO and LUMO energies, electrophilicity, and global hardness. Density functional theory based local reactivity descriptors such as Fukui functions and local softness are calculated to investigate the most probable active sites of the complexes.

Tunable Supramolecular Nanoarchitectures Constructed by the Complexation of Diphenanthro‐24‐Crown‐8/Cesium(I) with Nickel(II) and Silver(I) Ions

“…However, the absorption band centred at 232 nm and 272 nm decreased dramatically upon titration with Ni(ClO 4 ) 2 which indicated the binding of phenanthroline with metals. [8] The immensely attenuation of fluorescence intensity at 450 nm further confirmed the binding of phenanthroline with Ni 2 + (Figure 2d). The binding constant (K S ) was determined as 1.80 × 10 8 M À 1 ( Figure S6a,b).…”

“…Matrix‐assisted laser desorption/ionization‐time‐of‐flight mass spectrometry (MALDI‐TOF‐MS) confirmed the 1 : 1 complex DPC/Cs + (m/z 785.164, calcd value 785.159 for [M] + , Figure S3). However, the absorption band centred at 232 nm and 272 nm decreased dramatically upon titration with Ni(ClO 4 ) 2 which indicated the binding of phenanthroline with metals . The immensely attenuation of fluorescence intensity at 450 nm further confirmed the binding of phenanthroline with Ni 2+ (Figure d).…”

Oxidative bromination and oxidation of organic substrates catalyzed by bis[2,2'‐hydroxyphenylbenzimidazole]Fe(III) complex entrapped in zeolite‐Y cavity

“…Compared with non‐encapsulated complex, the peaks were relatively broadened upon encapsulation, which could be due to the interaction of metal complex with the walls of the zeolite cage. During the course of interaction, metal complex may perturb the active sites present within the zeolite, inducing different interaction energies and modifying the redox potential at different places in the zeolite . If there is any drastic decrease in peak currents for zeolite modified electrode, then the electron transfer occurs via an extra‐zeolite mechanism.…”

“…During the course of interaction, metal complex may perturb the active sites present within the zeolite, inducing different interaction energies and modifying the redox potential at different places in the zeolite. 60 If there is any drastic decrease in peak currents for zeolite modified electrode, then the electron transfer occurs via an extra-zeolite mechanism. CV of the encapsulated complex showed no decrease in peak currents and was found to be independent of scan rate accompanied with exceptional stability for a prolonged time without any change in redox potential values ( Fig.…”

Zeolite-Y encapsulated VO[2-(2′-hydroxyphenyl)benzimidazole] complex: investigation of its catalytic activity towards oxidation of organic substrates

“…Compared to non-encapsulated complex, the peaks were relatively broadened and average reduction potential values were shifted to more positive values upon encapsulation which was mainly attributed to the interaction of metal complex with the walls of the zeolite matrix. During the course of interaction, metal complex may perturb all the active sites present within the zeolite, inducing different interaction energies and alter redox potential at different places in the zeolite [31]. The alteration of peak potential indicated that the metal complex is encapsulated inside the zeolite matrix and not present on the external surface.…”