Other Halogenides

Chloral, anhydrous, stabilised CCI3CHO [2075] Methyl chloroformate CICOOCH3 [1238] 

Ethyl chloroformate CICOOC2H5 [1182] -Propyl chloroformate CICOOC3H7 [2740] -Butyl chloroformate CICOOC4H9 [2743] Methyl chloroacetate CH2CICOOCH3 [2295] Ethyl chloroacetate CH2CICOOC2H5 [1181] 

Chloral CCI3CHO and chloroacetaldehyde CH2CICHO are aggressive towards aluminium in the presence of water or even humidity, because they release hydrochloric acid upon decomposition. Chloroethanol CH2CICH2OH, on the other hand, has no action on aluminium. Aluminium equipment is used for storing and transporting this product, as well as in the production of plastics made from chloroethanol. 

In the absence of humidity and at room temperature, aluminium resists in contact with benzoyl chloride CeHsCOCl. In the presence of humidity, this compound decomposes and releases hydrochloric acid that attacks aluminium. At elevated temperatures, and especially close to its boiling point (198 °C), benzoyl chloride attacks aluminium. 

The Action of Boiling Alcohols and Dehydrated Phenols on Aluminium 474 

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Other halogenides were used [85] such as Cl — CH2 — O — CH2 — Cl. Thus, Gosnell et al. [24] carried out the following reaction ... 

The nature of the counterion in methyleneimmonium salts derives from the preparation method, as in the abovementioned examples however chloride or iodide anions are actually mostly reported. It is worth noting that morpholinomethyl fluoride, as distinct from the other halogenides, is a distillable liquid that does not exhibit salt behavior, due... 

Acid Halogenides. For acid halogenides the name is formed from the corresponding acid radical if this has a special name (Sec. 3.1.2.10) for example, NOCl, nitrosyl chloride. In other cases these compounds are named as halogenide oxides with the ligands listed alphabetically for example, BiClO, bismuth chloride oxide VCI2O, vanadium(lV) dichloride oxide. 

In the CeSI (115) and NdSBr (334) type of structure, bromine and iodine are coordinated to five metal ions (four of the same layer, and one of the opposite layer) and four halogen ions of the double layer. In the SmSI type (335), iodine is coordinated to three metal ions of a [LS] layer and three other iodine ions of the double layer. In the FeOCl type of compound, such as ErSCl (355) and LuSBr (85), the halogen is surrounded by a polyhedron formed by six sulfur and four halogenide ions. 

As far as the mechanism of thermal decomposition is concerned, halogenide binuclear clusters with multiple M-M bonds differ considerably from other clusters in their stronger tendency to undergo disporportionation reactions to... 

Exhaustive studies on well-defined systems are rather scarce (4) nevertheless 3 systems thoroughly analyzed by independant research groups are of outstanding interest a) the quaternization of polyvinylpyridines by alkyl halogenides (20-25) b) the chlorination of polyethylene (13,26-28) c) the basic or acid hydrolysis of PMMA (29-31). On the other hand, neighbouring groups effects have been quantitatively taken into account for the kinetic analysis of periodate oxidation of amylose (32,33). 

Also, other metal halides can aggregate with monoorganozinc halogenides, as was shown by the X-ray crystal structure determination of [(Me3Si)2(MePhNSiMe2)C]ZnBr2Li... 

Because of its favorable kinetic and thermodynamic properties, norbomene can be polymerized with simple transition-metal halogenides.99 116 Even RuC13, which is not active in other metathesis reactions, is effective in the ring-opening polymerization of norbomene.117118 Developments in the early 1990s include the use of... 

The other alkali halogenide molecules are also largely ionic. The energy curves for a representative molecule, sodium chloride, are shown in Figure 3-5. At very large internuclear distances the covalent structure is more stable than the ionic structure but at about 10.5 A the... 

We may attempt to make a rough quantitative statement about the bond type in these molecules by the use of the values of their electric dipole moments. For the hydrogen halogenides only very small electric dipole moments would be expected in case that the bonds were purely covalent. For the ionic structure H+X-, on the other hand, moments approximating the product of the electronic charge and the internuclear separations would be expected. (Some reduction would result from polarization of the anion by the cation this we neglect.) In Table 3-1 are given values of the equilibrium internuclear distances r0, the electric moments er0 calculated for the ionic structure H+X , the observed values of the electric moments /, and the ratios of these to the values of er0.ls These ratios may be interpreted in a simple... 

The values of the electric dipole moments of the alkali halogenide gas molecules are found to be about 80 percent of cr0 for example, for KC1 the value of r0 is 2.671 A and that of n is 10.48 D which is 82 percent of er0. The deviation of from er0 is about the magnitude expected to result from the polarization of each ion in the electric field of the other, and because of the uncertainty in the theoretical calculation of the polarization correction it is not possible to say more than that the observed moments agree roughly with those expected for completely ionic structures. 

Work on the direct determination of the electron affinities of halogen atoms was begun by Mayer,7 who, with his students, measured directly the equilibrium constant for dissociation of alkali halogenide gas molecules into ions or of gas halogenide ions into atoms and electrons. Other methods have also been used, especially some involving mass... 

It is possible to extend the treatment of this section, based on Equation 13-9, to crystals other than the alkali halogenides, with suitable choice of standard radii. It is found that the standard radii differ somewhat in general from the univalent radii of Table 13-3, because of the different choice of values of n. An approximate value for the standard radius of a multivalent ion can be obtained by multiplying its crystal radius by z f z being the magnitude of the valence of the ion this is the correction factor from crystal radius to univalent radius qorresponding to n = 9. 

It can be concluded from these experimental results that in alkaline media the 2-octyl nitrate behaves like a typical ester (Day and Ingold (50]). In neutral media, on the other hand, it behaves like an alkyl halogenide or like an ester of sulphuric acid. 

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