Iron clathrate

The recent enthusiasm for high fiber foods may carry a special challenge in considering food/drug toxicities. Vegetable fiber diets have been shown to reduce the toxicity of some drugs for animals (30). Presumably, phytates hold inorganic ions in a clathrate matrix that prevents absorption of the metal from the gut, other substances, e.g. bile acids, may also be bound (31). The bioavailability of iron as influenced by phytates in cereal foods via the formation of... 

ABSTRACT. This paper reports the unusual relaxation effect in the Fe Mossbauer spectra of o -cyclodextrin( y -cyclopentadienyl)( y -ethylcyclopentadienyl)iron(II) clathrate. At low temperatures it consists of a simple quadrupole doublet. However, the Mdssbauer spectrum collapses to a broad peak at 320 K. This behavior is interpreted in terms of a model that a ferrocene molecule in the cavity of clathrate lattices rotates as temperature is raised.v The relaxation reaches a critical rate, a lifetime of the excited nuclear state. The relaxation time for the reorientation of ( y -cyclj pentadienyl) ( y-... 

Molecular rotation in the cavity has been discussed for many compounds using nmr(8,9), esr(lO) and Mossbauer spectroscopy(4,5). A complete description of the Mossbauer spectrum for such a case has been given by Gibb(4) for that of the 3 1 clathrate of thiocarbonyl diamide and bis( -cyclopentadienyl)iron(II). Evidence for conformational isomerism has been presented recently based on the ir spectra of y-cyclopentadienylmetal carbonyl complexes such as CpFe(CO) SiCl Me(ll), ip -MeC H Mn(CO) (P(OMe) )(12) and others(13), and on the Mossbauer... 

Fig. 3. A fit between the Mossbauer spectra of the 0(-CyD-( 77 cyclopentadienyl)(7 -ethylcyclopentadienyl)iron( II) clathrate and tne theoretical curve. Here p =p =p and a single relaxation time is taken. x y z...

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