Bismuth electronic structure

Since these ho mo polyatomic Ziml) anions and cations are devoid of ligands, they are sometimes referred to as "naked" dusters. In general there is a good correlation between electronic structure and geometry as predicted by Wade s rules for these dusters, though some exceptions are known. Thus whereas Sn and Bi are isoelec Ironic, they have different structures, the latter violating the rules. Only a small distortion of the bismuth canon, however, would convert it to the geometry observed for the tin duster. 

No Bi2Xi compound is known, but it has long been known that when metallic bismuth is dissolved in molten BiCl3 a black solid of approximate composition BiCl can be obtained. This solid is Bi24Cl28, and it has an elaborate constitution, consisting of four BiCll", one Bi2Clg, and two Bi + ions, the structures of which are depicted in Fig. 10-5. The electronic structure of the Bi + ion, a metal atom cluster, is best understood in terms of delocalized molecular orbitals. Other low-valent species present in various molten salt solutions are Bi+, Bi3+, Bi +, and Bi +. The last, in Bi8(AlCl4)2, has a square antiprismatic structure. 

Bismuth has traditionally been considered a purely third body-(ensemble) type modifier [67] that exerts little influence on the platinum electronic structure, whereas... 

Indeed, around 1980, first experimental results on atomic parity violation have been reported, in particular measurements of the optical activity of bismuth, thallium and lead vapours as well as measurements of an induced electric dipole (El) amplitude to a highly forbidden magnetic dipole transition (Ml) in caesium. These experiments have nowadays reached very high resolution so that even effects from the nuclear anapole moment, which results from weak interactions within the nucleus, have been observed in caesium. The electronic structure calculations for caesium are progressing to a sub-percent accuracy for atomic parity violating effects and the reader is referred to chapter 9 of the first part of this book [12]. 

The most striking property of water is that its solid form is less dense than its liquid form ice floats at the surface of liquid water (Figure 6.8). With a few exceptions, (for example, silicon, gallium, germanium, bismuth, and pure acetic acid), the density of almost all other substances is greater in the solid state than in the liquid state. To understand why water is different, we have to examine the electronic structure of the H2O molecule. As we saw in Chapters 2 and 3, there are two pairs of nonbonding electrons, or two lone pairs, on the oxygen atom ... 

Transition Metal Complexes Related to the Simon test is a family of color-producing reactions based on transition metal complexes (coordination complexes) and tightly associated ion pairs. Coordination complexes arise from a Lewis acid-base interaction between a metal cation, such as cobalt, and an atom with unshared electrons, such as water or, in the case of drugs, basic nitrogen found in alkaloids and amines. Metals that have been used in these reagents include copper, vanadium, bismuth, and cobalt Cobalt, as part of two common reagents (cobalt thiocyanate and Dilli-Koppanyi) is perhaps the most versatile. Cobalt has an electron structure of 3d 4s, while ttie cation has a 3d (2 ) or 3d (3 ") structure. 

The analysis of the vibrational bands then yielded vibrational corrections to the observed rotation constants, which allowed the equilibrium rotation constants, and from them the equilibrium structure, to be derived. The Bi—H bond length was 1.7759 A and the H-B-H angle 90.48°. These are in excellent agreement with values of 1.7829 A and 90.08° calculated at the CCDS(T) level of theory with a relativistic pseudopotential for the core bismuth electrons, and a huge basis set, (12sl2p9d3f2g)/[6s6p4d3f2g], for the remaining 23 electrons. 

Kim, T.W., Hut, S.G., Hwang, S.-J., Park, H., Park, Y Choi, W and Choy, J.-H. (2007) Substitution effect of pentavalent bismuth ions on the electronic structure and physicochemical properties of perovskite-structured Ba(lno,5Tao,5- tBiJ O3 semicondudors. Mater. Res. Bull,... 

Although all of the superheavy elements will show relativistic effects in their chemistry, the clearest case may be element 115 (eka-bismuth), which we have used for illustration above. Keller, Nestor, and Fricke [25] have made some detailed predictions of the chemical properties of element 115 based on extrapolations of the properties of elements of group V and relativistic calculations of electronic structure. Their results indicate that the chemical... 

Analytical electron microscopy permits structural and chemical analyses of catalyst areas nearly 1000 times smaller than those studied by conventional bulk analysis techniques. Quantitative x-ray analyses of bismuth molybdates are shown from lOnm diameter regions to better than 5% relative accuracy for the elements 61 and Mo. Digital x-ray images show qualitative 2-dimensional distributions of elements with a lateral spatial resolution of lOnm in supported Pd catalysts and ZSM-5 zeolites. Fine structure in CuLj 2 edges from electron energy loss spectroscopy indicate d>ether the copper is in the form of Cu metal or Cu oxide. These techniques should prove to be of great utility for the analysis of active phases, promoters, and poisons. 

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