Iodine L-edge XAFS study of linear polyiodide chains in amylose and α-cyclodextrin

Abstract

We performed iodine L edge XAFS measurements on blue-black amylose-iodine complex to obtain information about the electronic and geometrical structures of polyiodide chain included in amylose helix. Measurements were also carried out on crystalline «-cyclodextrin-iodine complex («-cyclodextrin)2¡Cd0 5¡I5¡27H2 O, in which the polyiodide chain is known to consist of I 5 unit. It was found that the XANES spectra of these complexes have similar line shapes except for some minor differences, indicating that there are close similarities in the nature of polyiodide chains in these complexes. Besides their similarity, difference in the intensity of the peak at the L1 absorption edge was observed. Its implication for the electronic and geometrical structures is also discussed.

Electrically Activated Conductivity and White Light Emission of a Hydrocarbon Nanoring–Iodine Assembly

“…5p transition of an iodine atom. [15] This observation is Figure 1. Electric-stimuli-responsive porous materials.…”

“…[15] This result showed that the above-mentioned antibonding molecular orbitals were being occupied, that is,i odine molecules should receive electrons from the anode or CPP,though its valence value is not clear. …”

Saccharide Blocking Layers in Solid State Dye Sensitized Solar Cells

“…This improved performance most probably results from the structural flexibility of the amylose, facilitating its penetration into the film pores and adsorption to the dye sensitized film surface, consistent with previous studies which have reported greater flexibility of amylose relative to cyclodextrin in forming inclusion complexes. [24] The inclusion of amylose in the device structure does not appear to impact detrimentally on device stability. Indeed prolonged storage trials (over one month) indicated improved stability of devices including the amylose layer relative to control devices.…”

Analytical Methods for Iodine and Iodides

“…In particular, in iodine molecules or polyiodide ions where the 5pσ* molecular orbital is not completely filled, iodine l I -edge X-ray absorption spectra shows a sharp peak at the absorption threshold, which corresponds to iodine 2s → 5pσ* transition, and the intensity of this peak can be a quantitative measure of the valency of the iodine/iodide species in the sample under study [51]. It is also possible to determine the three-dimensional local structure around the X-ray-absorbing iodine atom as well as the electronic structure by performing multiple-scattering XAnes calculation from structural models and comparing the calculated spectra with the experiment [52][53][54].…”