Halides oxyhalides

Systematic features in the structural chemistry of the uranium halides, oxyhalides and related transition metal and lanthanide halides, J. C. Taylor, Coord. Chem. Rev., 1976, 20,197-273 (205). 

Chemical transport reactions involving the element and/or an elemental subhalide and a transition metal halide/oxyhalide. The components are heated in evacuated sealed glass tubes at 100-300 °C for a period of days to weeks. Applying a small temperature gradient (10-20 °C) leads to gas phase transport and crystallization at the cooler end of the ampoule [19]. 

Other Halides. TaBr5 [13451-11-1] and Tal5 [14693-81-3] are well known but do not find industrial application. An excellent overview of the various halides, oxyhalides, and their reactions is available (75). 

Hala, J. Halides, Oxyhalides and Salts of Halogen Complexes of Titanium, Zirconium, Hafnium, Vanadium, Niobium and Tantalum, Vol, 40, Elsevier Science, New York, NY, 1989. 

In reporting a Ziegler-Natta catalyst, the kind of transition metal compound should not be omitted. Group 4-8 transition metal compounds, such as halides, oxyhalides, alkoxides, acetylacetonates, etc., have been used as catalyst precursors with activators such as alkyl derivatives or hydrides of group 1-4 metals. Titanium chlorides and triethylaluminium are most commonly applied for the preparation of heterogeneous catalysts in an aliphatic hydrocarbon medium. Also, vanadium oxychloride or acetylacetonate and dialkyaluminium chloride are often used for the preparation of homogeneous catalysts in an aliphatic hydrocarbon or an aromatic hydrocarbon medium. 

The xenon halides, oxyhalides, and oxides are isoelec-tronic with many other compounds and ions containing halogens. Give a compound or ion, in which iodine is the central atom, that is isoelectronic with each of the following. 

The last three chapters summarize unique structural and chemical features of a variety of glasses. They also provide an overview of the important aspects of the glass systems. Chapters 12 and 13 discuss respectively oxide and chalcogenide glasses particularly in view of their chemistry, structure and a number of special phenomena associated with them. In chapter 14, synthesis, structure and properties of halide, oxyhalide, oxynitride and metallic glasses are discussed. Some aspects of glass-like carbon have also been presented. 

Niobium(v) and Tantalum(v).—Halides, Oxyhalides and Related Compounds. The ability of TaFj to act as a fluoride ion acceptor in anhydrous HF has been exploited in the preparation of salts of the AsH, HjS, and PH ions... 

Binary and Ternary Compounds and Related Systems.—Halides, Oxyhalides, and if Molecular force fields for MXg (M = MoorW X = For Cl)... 

This early study is eoncemed with the preparation and the investigation of the properties of thorium metal and of a large number of eompounds oxide, hydroxide, various halides, oxyhalides, halogenocomplexes, their hydrates and adducts with ammonia. Elemental analyses were given for many of the compounds studied. Enthalpies of solution at 288 K of the metal in cQ. 3.6 hd OCl and of a number of compounds in cq. 16000 H2O were reported. Values were given without any detail. Although the concentration of thorium in the calorimetric solutions was not specified in every case, it was assumed by this review to be the same throughout. 

Most of the molecular relativistic calculations were performed for compounds studied experimentally various halides, oxyhalides and oxides of elements 104 through 108 and of their homologs in the chemical groups. The aim of those works was to predict stability, molecular geometry, type of bonding (ionic/covalence effects) and the influence of relativistic effects on those properties. On their basis, predictions of experimental behavior were made (see Section 3). A number of hydrides and fluorides of elements 111 and 112, as well as of simple compounds of the 7p elements up to Z=118 were also considered with the aim to study scalar relativistic and spin-orbit effects for various properties. 

Volatility studies of various volatile halides, oxyhalides and/or oxides has been the subject of an extensive experimental research fi om 1969 on when Zvara et al. performed first experiments with RfCU [45,196-198]. Since then, volatility studies were performed for group-4 and -5 chlorides, bromides and oxychlorides, group-6 and -7 oxychlorides and group-8 oxides. The experiments have established a number of trends in volatilities of the heaviest element compounds, while they have also revealed a number of controversies. Results of... 

Molybdenumfvi) and Tungsten(vi).—Halide, Oxyhalide, and Related Complexes. The MF6-XeF2 (M = Mo or AV) binary systems have been studied by... 

Soga, T., Inoue, Y, and Ross, G A., Analysis for halides, oxyhalides and metal oxoacids by capillary electrophoresis with suppressed electroosmotic flow. Journal of Chromatography A 1995, 718, 421 28. 

The XEOL of rare earths (usually Sm, Eu, Gd, Tb and Dy) present at the 100-1000 ppm level in a wide variety of simple, binary, ternary and quaternary oxide host systems have been reported by Jaworowski et al. (1968), Takashima et al. (1969), Kawaguchi et al. (1969), Saranathan et al. (1970), DeKalb et al. (1970) and D Silva et al. (1970). In addition a limited number of halides, oxyhalides, sellenides and tellurides have been shown by Low et al. (1974,J,... 

Hala J (1989) Halides, oxyhalides and salts of halogen complexes of titanium, zirconium, hafnium, vanadium, niobium and tantalum. lUPAC, Blackwell, London... 

Table 8 Bond lengths (in A) of halides, oxyhalides and oxides of group 4—8 elements as a result of the 4c-DFT [159-170] and RECP CCSD(T) [171] calculations in comparison with experiment...

Results of the 4c-DFT and RECP calculations of various properties—optimized geometries (R and bond angles), Dg, IP, a, and —of the halides, oxyhalides and oxides of group-4 through 8 elements are summarized in Tables 8, 9. The and Re are also depicted in Fig. 19. 

In the past, DS DV calculations were helpful in establishing some correlation between electronic structure parameters and volatility of halides, oxyhalides and oxides known from macrochemistry [6, 11]. It was established, e.g., that covalent compounds (having higher OP) are more volatile than ionic, and that molecules with dipole moments interact more strongly with a surface than without those, and that the sequence in the adsorption energy is defined by the sequence in dipole moments. 

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