Anion oxyhalide

Balagopalakrishna, C., Kimbrough, J. T., and Westmoreland, T. D., 1996, Electronic structural contributions to g values and molybdenum hyperfine coupling constants in oxyhalide anions of molybdenum(V), Inorg. Chem. 35 7758n7768. 

Those oxyhalide anions that find use are most often used as alkali metal salts. A particular metal is often chosen to optimize physical properties for example, LiC104 is used as an oxidant in rocket propellants because the light metal... 

Several oxyhalide anions have also been characterized, for example, [AbOClg]" and [Al402Clio] . 

DIFFERENTIAL PULSE POLAROGRAPHIC DETERMINATION OF TeO " AND VOJ IN PRESENCE OF SOME OXYHALIDE ANIONS... 

Resolution and trace determination of inorganic oxyanions are important for assay purposes in commercial samples. The dc polarographic behaviour of these oxyanions and the resulting application have been described earlier. The detection limit of dc polarography is usually about 10 M but may be higher under non-optimum conditions. Since differential pulse polarography (dpp) and voltammetry should improve sensitivity at trace level concentrations, the use of dpp and voltammetry for determination of some oxyanions has been studied. In the present work applicability of dpp for quantitative trace determination and resolution of TeO " and VO in presence of some oxyhalide anions such as BrOj, lOj and 10 is investigated. 

Differential Pulse Polarographic Behaviour ofTeOl and VO in Presence of Some Oxyhalide Anions... 

The optimum conditions for the analytical determination of TeO in presence of BrO, 10 and IO7 were found to be a drop time of 1 s, scan rate of 2 mV/s and a pulse amplitude of 100 mV. Response of the differential pulse peak height (ip, /lA) with the concentrations of TeO is linear at the optimum pH in presence and in absence of oxyhalide anions. The results of determination and resolution of TeO " in presence of oxyhalide anions are based on the calibration curves of TeO " alone by this technique. Table 1 shows the results of determination of TeO in presence are based on the comparison of measured ip... 

Environmental directives and legislation about elemental speciation have been limited. Therefore analytical laboratories have often lacked the incentive to invest in the necessary technologies to perform chemical spedation. However, this situation is changing, and methods in effed include EPA Method 6800 for spedation of chromium, EPA Method 314 for perchlorate, EPA Method 317 for oxyhalide anions, EPA Method 8323 to detect organotin compounds, and several others. 

Oxyhalide Glasses. Many glasses contain both oxide and haUde anions. The introduction of haUdes into an oxide glass typically serves to reduce the glass-transition temperature, T, and to increase the coefficient of thermal expansion. Oxyfluorophosphates have been investigated as laser host... 

The high values of E generally characteristic of the decomposition reactions of metal oxyhalides are widely interpreted as evidence that the initial step in anion breakdown is the rupture of the X—O bond and that the energy barrier to this reaction is not very sensitive to the properties of the cation present. Information of use in the formulation of reaction mechanisms has been obtained from radiolytic studies of oxyhalogen salts [887-889],... 

Hautman DP, Bolyard M. 1992a. Analysis of oxyhalide disinfection by-products and other anions of interest in drinking water by ion chromatography. J Chromatogr 602(l-2) 65-74. 

Ion chromatography is the most convenient analytical approach for the determination of most inorganic anions, including oxyhalides in potable and wastewaters and solid waste extracts. The method has been approved by... 

Common inorganic anions F, N03-, SO42" oxyhalides and carboxylates, such as acetate and formate Alkali and alkaline earth metal ions Na, K+, Ca2+ ammonium Alkali and alkaline earth metal ions Li, Na, K, Mg2, ammonium ion alkyl amines methyl amine, triethyl amine, and morpholine... 

The bismuth(lll) halides are moisture sensitive and are readily converted into the oxyhalides BiOX (equation 1). Addition of acid to aqueous suspensions of the oxyhalides will regenerate BiX3, which exist as complex halo anions in solution. Addition of ammonium hydroxide to such solutions results in the formation of insoluble Bi(OH)3, which is easily dehydrated to the oxide. 

The transition metal oxyhalides occur with four main structure types (FeOCl, AlOCl, SmSI, and PbFCl) but only the FeOCl structure undergoes topotactic redox reactions. A layer of the orthorhombic FeOCl structure is shown in Figure 21. The structure is characterized by double sheets of distorted octahedra that share edges. Each iron atom is coordinated to four oxide anions and two chloride ions, with the two chloride ions in cis octahedral positions on the outside of the layer. The arrangement of octahedra within a layer is similar to that found in y-FeOOH and y-AlOOH. 

In addition to finite oxyhalide ions there are infinite oxyhalide ions in some complex oxyhalides. Examples include the anion in K2(Nb03F), which has the K2Nip4 (layer) structure (see Table 10.11), and the cis octahedral AX5 chain ion in K2(V02F3), F atoms forming the bridges. 

Finite ions and neutral molecules containing 0 directly bonded to a metal atom are formed by many transition metals. They include molecular oxyhalides and oxyhalide ions, which are included in Chapter 10, vanadyl and uranyl compounds, and numerous oxo-molecules and ions of metals such as Mo, Re, Os, etc. We give here a few examples of complexes of which the structures have been determined. The octahedral ion in K2 [0s 02(0H)4] has the same (trans) configuration as the anion in K2(0s02Cl4). Rhenium forms many octahedral ions (Re X40L) where X is halogen and L is H2O, CH3CN, etc. 

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