Hectorite Complexes with Cu(II) and Fe(II)-1,10-Phenanthroline Chelates

Berkheiser, V. E.

doi:10.1346/ccmn.1977.0250206

Cited by 59 publications

(29 citation statements)

References 24 publications

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“…Our results from the intercalation of Fe(II) phenanthroline are broadly in line with the observations of Berkheiser & Mortland (1977) and Loeppert et al (1979). It should be noted that our 28 A d-spacing is stable to washing and is not therefore due to intersalation as might be anticipated from the data of Berkheiser & Mortland.…”

Section: Discussionsupporting

confidence: 91%

Preparation and characterization of iron oxide pillared montmorillonite

et al. 1988

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A B S T RA C T : Pillared smectites in which the pillars consist of iron oxide are expected to have interesting and unusual magnetic properties. Several possible routes by which such materials might be made have been investigated, namely intercalation of hydroxy-Fe(III) polycations, mixed hydroxy-Fe(III)/Al polycations, phenanthroline-Fe(II) cations, and trinuclear Fe(III) acetato cations into Na-montmorillonite. Only the last of these yielded a pillared clay (PILC) on calcination. The products have been characterized using X-ray powder diffraction and 57Fe M6ssbauer spectroscopy. The precursor Fe-PILC has a d-spacing of 21 A and expands to 23 A on solvation with glycol. The calcined Fe-PILC has a d-spacing of 19 A (gallery height 9.4 A) and does not expand with glycol, confirming cross-linking of the layers. From M6ssbauer spectra at 4.2 K it is estimated that there are of the order of some hundred Fe atoms per pillar.Pillared or cross-linked smectites, in which the interlayer is converted into a two dimensional zeolite-like structure, have recently attracted much interest because of their catalytic and molecular sieving properties (Pinnavaia, 1983;Barrer, 1986). The best understood pillared clays (PILCs) are those in which Al oxide pillars act as molecular-sized props permanently separating the silicate layers of the clay, and the structure of these materials has been investigated using 27A1 and 29Si solid state MAS NMR (Tennakoon et al., 1986;Plee et al., 1985Plee et al., , 1987. If, however, the pillars are formed of Fe oxide instead of A1 oxide, interesting and novel magnetic properties may be expected (Gangas et al., 1985) and M6ssbauer spectroscopy can be utilized to obtain structural information.Metal oxide pillared clays are normally the product of a two step process. The first step is one of cation exchange in which the simple interlayer cation of a smectite (usually Na +) is replaced by a large complex cation. The second step consists of a heat treatment which crosslinks the silicate layers. In this paper, the terms precursor-PILC and calcined-PILC are used in order to make a clear distinction between the products obtained after each step.The complex cation which is used in the preparation of A1-PILCs is the Keggin-like ion [AllaO4(OH)24(H20)12] 7+ (Baes & Mesmer, 1976). In this study we have investigated the PILC-forming potential of a number of large Fe cations which can occupy the exchange sites in smectite interlayers. These are hydroxy-Fe(III) polycations, mixed hydroxy-Fe(III)/Al cations, phenanthroline-Fe(II) complexes and trinuclear Fe(III) carboxylate complexes. CHARACTERISTICS OF METAL OXIDE PILLARED CLAYSIntercalation of complex cations into a smectite followed by heat treatment may, or may not, result in the formation of a PILC. The following three criteria have been used to identify 9 1988 The Mineralogical Society

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Section: Discussionsupporting

confidence: 91%

Preparation and characterization of iron oxide pillared montmorillonite

et al. 1988

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“…The agreement between the OP and the other methods for surface area determination of montmorillonite is perhaps due to this fact. Bower (1963) observed that the OP adsorption on a bentonite is associated with an increase of 5.3-7.8 fk in the basal spacings, while Berkheiser and Mortland (1977) obtained an increase of 3.8 and 3.9 A in the basal spacings of hectorite saturated with Fe(II) and Cu(II) phenanthroline complexes, respectively. The present XRD data and those of Bower (1963) indicate that two molecules of OP could be present within the interlamellar spaces (the OP molecular thickness is about 3 /k), though perhaps not in a totally uniform manner.…”

Section: Resultsmentioning

confidence: 99%

Adsorption of 1,10-Phenanthroline by Some Clays and Oxides

Bussetti

Ferreiro

Helmy

1980

Clays and clay miner.

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Abstract--The adsorption of 1,10-phenanthroline (OP) onto some clays and oxides was studied as a function of concentration, pH, and time. The adsorption was found to be irreversible and the isotherms, except for silica gel, were hyperbolic and gave rise to plots similar to that of Langmuir. Kinetic and light scattering studies show that OP is adsorbed as a micellar unit composed on the average of 3.5 molecules/micelle. This fact explains the overestimation observed in the surface areas of some sorbents since no true monomolecular layer of OP is formed on the surfaces. The adsorption was also found to be pH dependent, attaining a maximum, independent of the sorbent, at about pH 6. This maximum was approximately at the same pH in which only the molecular form of OP began to be present. The partial desorption of OP as the pH increased beyond 6 is possibly associated with the aggregation of micelles on the surfaces.

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“…The small diffusion coefficients (typical solution value = 10 5 cm2/s) correspond well with what is known about the interaction of these species with clay surfaces. Strong interactions ofTTF § , MV (Raupach et aL, 1979;Hang and Brindley, 1970), and the trisdiimine species (Krenske et aL, 1980;Schoonheydt et aL, 1978;Velghe et aL, 1977;Mortland, 1965, 1966;Berkheiser and Mortland, 1977;Abdo et aL, 1981;DellaGuardia and Thomas, 1983) with the surface oxide layer have been observed by UV-VIS, nuclear magnetic resonance, and electron spin resonance techniques. These small values indicate that the activation energy required to jump from site to site is quite large.…”

Section: Quantitative Datamentioning

confidence: 99%

Clay-Modified Electrodes: A Review

Fitch

1990

Clays and clay miner.

145

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Abstract--Clay-modified electrode research indicates that adsorbed complexes are electroactive if the adsorption sites are clay edges. Interlayer adsorbed complexes may be electroactive ifa charge shuttle is added or if interlayer swelling is large. Conductivity of the film towards anionic species depends upon the swelling of the clay, which depends on the electrolyte concentration and speciation. The diffusion coefficients measured by electrochemical experiments agree well with alternative measurements.

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Hectorite Complexes with Cu(II) and Fe(II)-1,10-Phenanthroline Chelates

Cited by 59 publications

References 24 publications

Preparation and characterization of iron oxide pillared montmorillonite

Preparation and characterization of iron oxide pillared montmorillonite

Adsorption of 1,10-Phenanthroline by Some Clays and Oxides

Clay-Modified Electrodes: A Review

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