Layered Inorganic Materials as Redox Agents:  Ferrocenium-Intercalated Zirconium Phosphate

Abstract

The direct intercalation reaction of ferrocene (bis(eta5-cyclopentadienyl)iron(II), Fc) with a highly hydrated layered zirconium phosphate (ZrP) resulted in the formation of the ferrocenium ion (Fc+) within the ZrP material. The Fc+-intercalated ZrP material has an interlayer distance of 10.7 A. The intercalated material was used as an electron acceptor for the oxidation of both ferro-cytochrome c and the excited state of tris(2,2'-bipyridine)ruthenium(II) ([Ru(bpy)3]2+). Upon contact of the material with a 1.5 x 10(-5) M solution of ferro-cytochrome c, the UV-vis absorption spectrum shows the successful formation of ferri-cytochrome c. Luminescence spectroscopy shows that the Fc+-intercalated ZrP material quenches the luminescence of [Ru(bpy)3]2+. The excited-state quenching mechanism of [Ru(bpy)3]2+* by Fc+-intercalated ZrP follows a dynamic plus sphere of action model. The second-order dynamic quenching rate constant kq is 2.2 x 10(8) M(-1) s(-1).

Molybdocene dichloride intercalation into zirconium phosphate nanoparticles

“…That minimum distance is 4.38 Å when the Cp rings are perpendicular, and the Cp-Mo-Cp angle is parallel, to the ZrP layers. We have previously reported that another metallocene, ferrocene, also intercalates with the Cp rings perpendicular to the ZrP layers [8]. Adding the thickness of a layer of ZrP (6.6 Å) [6,23,24] we would have expected an interlayer distance of 10.98 Å, which is consistent with the 11.0 Å obtained from the XRPD experimental results.…”

“…Direct intercalation of metallocenes into q-ZrP has not been previously reported in the literature with exception of the direct intercalation of ferrocene for use as a redox agent in our own effort [8].…”

“…The highly hydrated phase of the layered ZrP is an acidic ion exchanger that has been used for the immobilization of several photo- [7], bio- [5] and redox-active compounds [8]. The applications for these materials can range from being used as catalysts [9], electron-transfer systems [7,8], drug carriers [5], and modified electrodes [8]. In addition, ZrP can be modified by manipulating certain variables in its synthesis to obtain a material with nanoscale dimensions [10], suitable for additional applications in the areas of nanotechnology and drug delivery.…”

Catalytic isomerisation of α-pinene oxide in the presence of ETS-10 supported ferrocenium ions

“…Thus, a study on the photocatalytic activity of ETS-10 for the conversion of organic substrates with different molecular widths [13], backed up by theoretical analysis of the ETS-10 structure [22], indicates that the pore limiting diameter of ETS-10 is about 5.6 Å. This is almost an exact match with the shortest dimension of the [Fc] þ ion, which can be considered a cylinder with dimensions of 6.8 Å Â 5.65 Å [23]. Indeed, it is known, for example, that the ferrocenium cation can fully penetrate the cavity of the organic host cucurbit [7]uril [24], which has a cavity opening diameter of 5.4 Å [25], to form a highly stable inclusion complex.…”

Transition Metal-Modified Zirconium Phosphate Electrocatalysts for the Oxygen Evolution Reaction

“…Figure 1C shows transmission electron micrographs of α-ZrP nanoparticles with the characteristic hexagonal nano-platelet structure with an average diameter and thickness of ~140 and ~15 nm, respectively. θ-ZrP can be directly ion-exchanged with large metal complexes, producing intercalated phases useful for artificial photosynthesis schemes, amperometric biosensors, vapochromic materials, θ-ZrP can be directly ion-exchanged with large metal complexes, producing intercalated phases useful for artificial photosynthesis schemes, amperometric biosensors, vapochromic materials, catalysis, Catalysts 2017, 7, 132 3 of 14 and drug delivery applications [31][32][33][34][35]. Herein, the layered structure of ZrP is leveraged to support active catalysts for the OER through the ion exchange of transition metal cations.…”