Arsenic chloride bonding

The formation of the heterocycle 1 from the xylylene-bis-phosphonium salt 2 and PCI3 proceeds via a detectable intermediate 3 in a cascade of condensation reactions that is terminated by spontaneous heterolysis of the last remaining P-Cl bond in a cyclic bis-ylide-substituted chlorophosphine formed (Scheme 1) [15]. The reaction scheme is applicable to an arsenic analogue of 1 [15] and to bis-phosphonio-benzophospholides with different triaryl-, aryl-alkyl- and aryl-vinyl-phosphonio groups [16, 18, 19], but failed for trialkylphosphonio-substituted cations here, insufficient acidity prohibited obviously quantitative deprotonation of the phosphonium salts, and only mixtures of products with unreacted starting materials were obtained [19]. The cations were isolated as chloride or bromide salts, but conversion of the anions by complexation with Lewis-acids or metathesis was easily feasible [16, 18, 19] and even salts with organometallic anions ([Co(CO)4] , [CpM(CO)3] (M=Mo, W) were accessible [20]. 

From what has just been said with regard to carbon, it is evident that the atomicity of an element is, apparently at least, not a fixed and invariable quantity thus nitrogen is sometimes equivalent to five atoms of hydrogen, as in ammonic chloride, (i H Cl), sometimes to three atoms, as in ammonia (N" H,), mid sometimes to only one atom, as in nitrous oxide (N,0). But it is found that this variation in atomicity always takes place by the disappearance or development of an even number of bonds thus nitrogen is either a pentad, a triad, or a monad phosphorus and arsenic, either pentads or triads carbon and tin, either tetrads or dyads and sulphur, selenium, and tellurium, either hexads, tetrads, or dyads. 

Table 6.4 contains some bond length and bond angle data for the hydrides, fluorides and chlorides of nitrogen, phosphorus and arsenic. The differences in the electronegativity coefficients (Allred-Rochow) in the compounds are also given. 

The first additions to a fluoro-ene were of chlorine and bromine to the C = C bond of allyl fluoride. Meslans used silvcr(I) fluoride, arsenic(III) fluoride, zinc(II) fluoride and antimony(III) fluoride to convert21 acetyl chloride to the fluoride, which was shown to have a reactive C — F bond. The first reaction on a saturated fluoride to retain the C —F link was by Collie.22 Tetramethylammonium fluoride was transformed to fluoromethane on heating which was then converted to chlorofluoromethane by treatment with chlorine. 

Although arsenic(V) chloride is unstable, the derivative anions are well known, though not as widely studied or used as the corresponding fluorides. In Cs3As2Cl9 the highly distorted AsCU octahedron has two types of As—Cl bonds, d(As—Cl) at 2.25 and 2.75 A, the latter suggesting an almost ionic bond.217... 

The overall effect of estuarine water on the hydridisation process is thus one of reducing yields of the three tin species tested. It is expected that not only the dissolved and particulate organics and chloride influence formation of Sn-H bonds, but that other aquated metal ions play an important role, too. Several workers have reported that, for example, arsenic(III), arsenic(V), copper(II), nickel(II), mercuiy(II), lead(II) and silver(I) interfere by unknown means at low concentrations [702,753],... 

Typical oxidising dopants used include iodine, arsenic pentachloride, iron(III) chloride and NOPF6. A typical reductive dopant is sodium naphthalide. The main criteria is its ability to oxidise or reduce the polymer without lowering its stability or whether or not they are capable of initiating side reactions that inhibit the polymers ability to conduct electricity. An example of the latter is the doping of a conjugated polymer with bromine. Bromine it too powerful an oxidant and adds across the double bonds to form sp3 carbons. The same reaction may occur with NOPF, but at a lower rate. 

Typical tetracoordinate arsenic compounds that contain an As-N bond are the aminoarsonium salts, the arsazenes, and the arsinimines." bi2,3i,i62 aminoarsonium chlorides are synthesized by the reaction of tertiary arsines with the following chloramines NH2CI, MeN(H)Cl, and Me2NCl (equations 91 and 92). > ... 

Arsenic in soilds has been fractionated by Jackson s T28) procedure for soil phosphorus (15. 27). In this laboratory, a modification of Jackson s procedure is being used on sediment solids. A series of 1 molar solutions of NH4CI, NH4OH, acid ammonium oxalate (29) and HCl are used in sequence. The chloride fraction, or exchangeable fraction, contains weakly adsorbed, coulombically bound arsenic. The hydroxide fraction, contains iron and aluminum arsenate precipitates and surface precipitates (i.e. adsorbed arsenic species having both chemical and coulombic bonding to oxide surfaces). The oxalate, or reductant soluble fraction, contains arsenic occluded in amorphous weathering products. The acid, or calcium, fraction contains arseno-apatites. 

Fe anchored amino-functionalized MCM-41 effectively adsorbs toxic oxyanions, arsenate, chromate, selenate and molybdate, in the aqueous solution. These adsorbents show ones of the largest adsorption capacities reported in the literature. The molar ratio, oxyanion / Fe, is 2.8, 1.8, 1.5 and 2.3, respectively. They are consistent with the coordination mmibers in the EXAFS structural analysis of adsorption complexes. Cr-Fe adsorption centre is uniform, where 2 1 complex is uniformly generated. On the contraiy, chloride ion remains in As- and Se-Fe complexes and two kinds of coordination with different bonding distances were found in As- and Mo-Fe complexes. 

Bonds to Sulphur or Selenium.— Arsenic, antimony, and bismuth trichlorides react with bis(2-mercaptoethyl) sulphide, liberating hydrogen chloride and forming the cyclic compounds (99).686 Complete spectroscopic data... 

In the reaction with halides of the less electropositive metals such as mercury,79 arsenic,80- 81 antimony,82 and indium,83 a stannane provides nucleophilic hydrogen and gives the new metal hydride (equation 15-27). Free radical inhibitors may be added to repress radical reaction of vinyl reactants. The preparation of vinylmercury hydride by this route involves the unusual use of tributyltin chloride as a solvent (equation 15-28).79 On the other hand, in the reactions of tributyltin hydride with Grignard reagents, RMgX, the hydrogen behaves as an electrophile towards R, and the Sn-Mg bonded compounds are formed.84... 

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