Abstract Background: Metalloporphyrin ions, with planar shape, have been known to intercalate horizontally and diagonally between montmorillonite layers. Perpendicular intercalation inside montmorillonite has not been reported earlier. This work aims at achieving perpendicular intercalation inside montmorillonite in natural clays. Possible intercalation inside other forms of natural clay will also be investigated. Methods: Natural clays were purified and characterized. The naked clay powder was then refluxed with tetra(4- pyridyl)porphyrinatomanganese(III) ion (MnTPyP+) solution in methanol with continuous stirring for different times. Electronic absorption spectra, atomic absorption spectra, Fourier Transform infrared spectra, scanning electron microscopy and X-ray diffraction were all used in clay characterization and in intercalation study. Results: The natural clay involved different phases, namely montmorillonite, biotite, kaolinite, illite and traces of quartz. Montmorillonite clay allowed horizontal, diagonal and perpendicular intercalation of the metalloporphyrin ions. Biotite allowed only horizontal intercalation. The mode of intercalation was deduced by monitoring the clay inter-planar distance value change. Intercalation occurred inside both micro- and nano-size clay powders to different extents. The nano-powder (average size ~50 nm) showed uptake values up to 3.8 mg MnTPyP/g solid, whereas the micro-size powder (average size ~316 nm) exhibited lower uptake (2.4 mg MnTPyP/g solid). Non-expandable clay phases did not allow any intercalation. The intercalated MnTPyP+ ions showed promising future supported catalyst applications. Conclusions: Depending on their phase, natural clays hosted metalloporphyrin ions. Montmorillonite can allow all three possible intercalation geometries, horizontal, diagonal and for the first time perpendicular. Biotite allows horizontal intercalation only. Non-expandable clays allow no intercalation. © 2016 Zyoud et al. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/ publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Background Metalloporphyrins are a widely studied class of compounds [1–5]. With their planarity, aromaticity and stability, they have been used as thermal catalysts [6–12], photo-catalysts [13], and electro-catalysts [14, 15]. MnTPyP+ ions are useful homogeneous catalysts, but to facilitate their recovery they have been supported onto different types of insoluble solid materials. The ions were chemically anchored to solid material surfaces [9, 16]. They were also encaps

Title

Chemistry Central Journal

Publisher

Springer International Publishing

Publisher Country

Palestine

Indexing

Scopus

Impact Factor

2.0

Publication Type

Prtinted only

Volume

10

Year

2016

Pages

9