Oxy halides

An important source of reference is another excellent review by Stern [844] this one is concerned with the high temperature properties of oxy-halides. The following general trends are found in salts containing an XO anion (X = Cl, Br and I) there are variations in stabilities in the sequences (i) (X =) Cl > Br > I for halogens in the same oxidation state, and (ii) XO4 > XOJ > XO2 > XCT for the different oxidation states of a particular halogen. 

The dioxide rapidly absorbs hydrogen halides, forming selenium oxy-halides ... 

Oxy halides of vanadium arc common, including VOP7, VOFj, VOC1, VOCli, VOCI3, VOBr and VOBr3. 

The main route to rhenium alkoxides is the interaction of halids and oxy-halids with alkali alkoxides or alcohols in presence of amines (method 5). As the important starting reagents can serve also Re2(CO),0 and Re207 (method 3) The preparation ofrhenium (V) and (VI) oxoderivatives by the anodic oxidation of metal in alcohols has also been described (method 2) (see Table 12.22). The bimetallic alkoxides ofrhenium and heavy transition metals can most efficiently be obtained by interaction ofrhenium (VII) oxide with the alkoxides ofthese elements in refluxing toluene ... 

Oxy-Halides —Oxytrifluoride—Pluophosphoric Acids—Oxytrichloride—Pyro-phosphoryl Chloride—Metaphosphoryl Chloride—Phosphoryl Monochloride — Phosphoryl Dichlorobromide — Phosphoryl Chlorodibromide — Oxy-tribromide—Metaphosphoryl Bromide—Oxyiodides. 

V.19 CONFIRMATORY TESTS FOR ANIONS In every case where the presence of any anion has been indicated, it must be confirmed by at least one distinctive confirmatory test. Conclusive tests for anions (halides, sulphate, oxy-halides, thiocyanate, phosphate, silicate, fluoride, cyanide and chromate) have already been given in Section V.18, it will, of course, be unnecessary to confirm these further. The following list, which, for the sake of completeness includes those anions already referred to, will assist the student in the choice of suitable tests. Full experimental details will be found in Chapter IV under the reactions of the anions the reference to these will be abbreviated as follows thus (IV.2, 3) is to be interpreted as Section IV.2, reaction 3. It is assumed, of course, that interfering acids are absent or have been removed. 

Single metal and mixed metal oxo alkoxides can also be prepared by reaction between metal halides, oxy halides, and alkali metal alkoxides.47,48 One of the first to be structurally characterized was a series of mixed Cd or Sn containing zirconium, tin, and titanium alkoxides.84,85 These and other examples are shown in skeletal form in Figure 3. 

The mere observation of the above correlations has been widely used to judge the parameters of macro volatility of the (oxy)halides of TAEs. Not enough attention has been paid to the fact that the evaluated — Aa(js// values fall between the corresponding Avap H and Asub H. It is not at all obvious that it must be so be if we imagine a molecule interacting with bare flat surface of fused silica and compare the situation with that of a molecule in the condensed phase, where it is tightly surrounded by a number of its own replicas see Fig. 5.4. 

In all cases the association of the lead is specific with the noble metal because the lead-carrying molecules, most probably oxy-halides, decompose on the noble metals sites leaving the lead on the surface. 

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