Additional Structure Data

Vegard s rule, i.e., the assumed linear increase of the lattice constants from that of Tm Se to (hypothetical) Tm Se, is often used to determine the Tm valence from the lattice constants, but this linear interpolation must be handled cautiously, see for example, Vettier [2]. An equation is proposed, based on a linear interpolation oetween the bulk moduli, which leads to a nonlinear relationship between the true valence from lattice constants and the Vegard valence . A calculated curve is in fair agreement with the results of other determination methods for a figure, see the paper, Neumann et al. [3]. 

NMR studies of Se in the range 4.2 to 400 K on Tmi oSe (a = 5.709A) and Tmo.gySe (a = 5.683 A) indicate, that the intermediate valence character of Tmo.gySe (at low temperatures) results from a random static distribution of integral valent Tm and Tm , but the results for Tmi oSe are consistent with equivalent Tm ions and temporal on-site fluctuations. As the temperature increases, the spectra of both samples approach each other and become almost identical at room temperature, Panissod etal. [9]. 

The chemical shift of X-ray K lines (related to Tm203) demonstrates a gradual transition from the practically trivalentTm inTmS through the mixed valence state in TmSe to practically divalent Tm in TmTe, Sumbaev [10, pp. 143/5]. The valence of Tm in TmSe is controlled by variation of the stoichiometry between 3 and 2.71 or by variation of the composition of solid solutions in the Tm(Te,Se) and (Tm,Eu)Se systems between 3 and 2, see the review of Kaldis etal. [11]. 

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B. Confirmatory and Additional Structural Data on Known Alkaloids... 

Once the alkaloid is purified, the absolute structure and stereochemistry can be determined by a combination of spectroscopic methods including H and C NMR spectroscopy, and high resolution mass spectrometry. All three methods should be in agreement on one structure for the compound in question. Additional structural data and confirmation can be obtained from the analysis of the trimethylsilyl ether derivative by GC-MS as indicated above [13]. The absolute stereochemistry can be determined by X-ray crystallography, which can be used whenever well-defined crystaf structure is obtained, either from the alkaloid itself or from its hydrochloride salt. 

During the process of conversion, a program may drop some information produced by other software because the format conventions cannot handle this additional information. For example, when the J ACMP format is converted to a Molfile, its content is reduced to structural data only, without spectra data. In other cases, a... 

A strict separation of these three types of databases is difficult hence most databases contain a mixture of data types. Therefore the classification given here is based on the predominating data type. For example, the major emphasis of a patent database is on hterature, whereas it also comprises numeric and structural data. Another type is the integrated database, which provides a supplement of additional information, especially bibhographic data. Thus, different database types are merged, a textual database and one or more factual databases. 

As discussed in Sec. 4, the icomplex function of temperature, pressure, and equilibrium vapor- and hquid-phase compositions. However, for mixtures of compounds of similar molecular structure and size, the K value depends mainly on temperature and pressure. For example, several major graphical ilight-hydrocarbon systems. The easiest to use are the DePriester charts [Chem. Eng. Prog. Symp. Ser 7, 49, 1 (1953)], which cover 12 hydrocarbons (methane, ethylene, ethane, propylene, propane, isobutane, isobutylene, /i-butane, isopentane, /1-pentane, /i-hexane, and /i-heptane). These charts are a simplification of the Kellogg charts [Liquid-Vapor Equilibiia in Mixtures of Light Hydrocarbons, MWK Equilibnum Con.stants, Polyco Data, (1950)] and include additional experimental data. The Kellogg charts, and hence the DePriester charts, are based primarily on the Benedict-Webb-Rubin equation of state [Chem. Eng. Prog., 47,419 (1951) 47, 449 (1951)], which can represent both the liquid and the vapor phases and can predict K values quite accurately when the equation constants are available for the components in question. 

In addition, Kqa data are given for some structured packing in Chapter 4 Absorbers—Inorganic Type. 

Some additional structural relations can be deduced from the data of Amstutz et In the reactivity of 2-chlorobenzothiazole with... 

Another important consideration is the comparison between gaseous and crystalline sulfoxides and sulfones. Such a comparison may yield information about intermolecular interactions in the crystal1. Unfortunately, very few data are yet available for confident use in such comparisons. The first requirement is, of course, that the same compound has been investigated both in the gaseous state and in the crystal. In addition, it is necessary that all the structural data correspond to the same physical meaning (cf. Reference 1). When these conditions are fulfilled, interesting conclusions2 may be reached on the basis of even small differences. 

A careful structural analysis using additional microwave data of 95% enriched 82 0 resulted in the to, r, and geometries compiled in Table 1 [26],... 

The syntheses and spectroscopic and electrochemical characterization of the rhodium and iridium porphyrin complexes (Por)IVI(R) and (Por)M(R)(L) have been summarized in three review articles.The classical syntheses involve Rh(Por)X with RLi or RMgBr, and [Rh(Por) with RX. In addition, reactions of the rhodium and iridium dimers have led to a wide variety of rhodium a-bonded complexes. For example, Rh(OEP)]2 reacts with benzyl bromide to give benzyl rhodium complexes, and with monosubstituted alkenes and alkynes to give a-alkyl and fT-vinyl products, respectively. More recent synthetic methods are summarized below. Although the development of iridium porphyrin chemistry has lagged behind that of rhodium, there have been few surprises and reactions of [IrfPorih and lr(Por)H parallel those of the rhodium congeners quite closely.Selected structural data for rr-bonded rhodium and iridium porphyrin complexes are collected in Table VI, and several examples are shown in Fig. 7. ... 

Oxygen-17 NMR spectroscopy has an immense potential for structural analysis of cyclic sulfoxides and sulfones as well as for providing insight into the nature of bonding within these two functional groups . Indeed, in addition to data concerning the NMR chemical shifts for several cyclic sulfoxides and sulfones, NMR chemical shift differences between several diastereotopic sulfonyl oxygens in both cyclic and acyclic systems have been reported . 

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