Bismuth structural data

Table 30 Some Crystal Structure Data for the Bismuth Halides...

X-ray absorption fine structure (EXAFS) can be a potentially useful technique that can give information about bonded atoms and coordination environments. EXAFS have been applied very rarely to E-M compounds, but some work has been reported. For example, the EXAFS data of solid samples of [Cp(CO)3Mo]2BiCl are consistent with the crystal structure data that indicate that the trimerization via intermolecular Bi-Cl interactions is broken in solution and replaced via coordination of solvent thf to the bismuth center.46... 

Shutov et al. carried out density functional theory (DFT) calculations on E[N(SiMe3)CH2CH2]3N (E = P, Sb, Bi) up to the PBE level of theory <2002IC6147>. The structural data obtained from geometry optimization on antimony and bismuth derivatives reproduced experimental trends, that is, a decrease in the Ndat-E distance from Sb to Bi. The values of electron density in Ndat-E critical point and the Laplacian of charge density for the azabismatrane indicated that a closed-shell interaction existed between Bi atom and Ndat atom. 

Much of the structural data are based on powder X-ray diffraction, but structures are typically polymeric with the bismuth in a distorted nine-coordinate environment similar to that in BiF3 or the Tysonite structure. There has been considerable interest in these compounds as fast fluoride ion conductors. ... 

Arsenic, Antimony and Bismuth Table 13.7 Structural data for antimony trihalides... 

Yeo I, Kim S, Jacobson R, Johnson DC (1989) Electrocatalysis of anodic oxygen-transfer reaction comparison of structural data with electrocatalytic phenomena for bismuth-doped lead dioxide. J Electrochem Soc 136 1395-1401... 

A diverse coordination chemistry is emerging for bismuth(III) made possible by a spacious and flexible coordination environment, allowing for coordination numbers in excess of 9. Although the available data are still limited, distinct trends are evident, and the polymeric solid-state features that may be assumed on the basis of high coordination numbers can be mediated by appropriate selection of organic-based ligands. The unusual structural arrangements observed for many types of complex may prove to be representative as the number of examples of such systems increases. 

These results suggest that the (101) superstructure observed on the (001) -phase at the catalyst s operating temperature is closely related to Bi2M02O9. A quantification of the microanalysis of the jS-preparation shows a Bi-deficiency. Similar results are observed in the reaction of the a-phase in propylene. In a C3 H6-O2 mixture under working conditions both phases show the presence of this superstructure similar to the jS-structure. The ETEM results are consistent with XPS and Raman data which show that the surface structure of the active bismuth molybdate is close to the jS-phase and that the jS-phase is more active (Matsurra et al 1980, Burrington et al 1983). In these studies dramatic increases in the activity... 

LoJacono et al. (108) also utilized X-ray diffraction methods to study the structural and phase transformations which occurred in the Bi-Fe-Mo oxide system. They detected two ternary compounds containing bismuth, molybdenum, and iron. One of the compounds formed when the atomic ratio Bi/Fe/Mo = 1 1 1 the other formed when the atomic ratio Bi/Fe/Mo = 3 1 2. The X-ray data indicated a close structural relationship of the bismuth iron molybdate compounds with the scheelite structure of a-phase bismuth molybdate. Moreover, their structures were similar to compound X. The structure of the Bi/Fe/Mo = 3 1 2 compound was identical to the compound reported by Sleight and Jeitschko (107). The authors proposed that the structures of both of the compounds could be viewed as resulting from the substitution of Fe3+ in the a-phase lattice. In the Bi/Fe/Mo = 1 1 1 compound, 1 Mo6+ ion is replaced by 2 Fe3+ ions one Fe3+ ion occupies a Mo6+ site the other Fe3+ ion occupies one of the vacant bismuth sites. In the Bi/Fe/Mo = 3 1 2 compound, the Fe3+ ion replaces one Mo6+ ion while the additional Bi3+ ion occupies one of the vacant bismuth sites. 

Application of Raman spectroscopy to a study of catalyst surfaces is increasing. Until recently, this technique had been limited to observing distortions in adsorbed organic molecules by the appearance of forbidden Raman bands and giant Raman effects of silver surfaces with chemisorbed species. However, the development of laser Raman instrumentation and modern computerization techniques for control and data reduction have expanded these applications to studies of acid sites and oxide structures. For example The oxidation-reduction cycle occurring in bismuth molybdate catalysts for oxidation of ammonia and propylene to acrylonitrile has been studied in situ by this technique. And new and valuable information on the interaction of oxides, such as tungsten oxide and cerium oxide, with the surface of an alumina support, has been obtained. 

In our investigation we have used BiOHal electrodes obtained by the exhaustive anodic oxidation of a bismuth layer with a thickness of about 200 nm on a platinum substrate in aqueous solutions of potassium halides (KHal) using the method previously reported in full details [93]. The resulted BiOHal films exhibited porous structure (according to the BET data, the surface area was 47, 25, and 6 m2/g for BiOCl, BiOBr, and... 

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