Boron sulfides phosphorus

Replacement of the carbonyl oxygen atom by sulfur may be effected by heating with phosphorus pentasulfide (49JCS2142), boron sulfide or silicon disulfide which gives high yields under mild conditions, as, for example, in the synthesis of 7-methoxy-2-methylchromene-4-thione (438) (69JCS(C)2192). Such compounds are more easily converted into their oximes or hydrazones than the oxygen compounds. 

An interesting topological effect is the increased terminal chlorination of fatty acids when they are adsorbed and aligned on alumina Silicon disulfide and particularly boron sulfide have been used with advantage instead of phosphorus pentasulfide to replace carbonyl oxygen by sulfur The addition of sulfur monochloride to olefins followed by reduction of the adduct with sodium sulfide provides a convenient inexpensive route to a large number of episulfides A direct conversion of ar. nitro compounds to isothiocyanates has been reported Sec. phosphines add easily to olefins under UV-irradiation Advances in peptide synthesis include the use of acyloxyphospho-nium salts prepared with hexamethylphosphoramide a simple synthesis with triphenyl phosphite , and the use 4-picolyl esters at the... 

Aminolysis of the corresponding halides is the preferred method for the synthesis of dialkylamino derivatives of boron,1 silicon,2 germanium,3 phosphorus,4 arsenic,5 and sulfur.6 (Dialkylamino) chlorosilanes are prepared stepwise by the reaction of silicon tetrachloride with dialkylamines. This method may be utilized equally well for the conversion of alkyl- or aryl-substituted halides [e.g., (CH3) SiCl4. ] or of oxide and sulfide halides (e.g., POCl3 or PSC13) to the corresponding dialkylamino compounds. 

Bis(a-aminomethyl)phosphines having a mobile hydrogen atom could be expected to undergo a borylation reaction with borane, hydrogen being evolved. In fact, bis(Af-phenylaminomethyl)-phenylphosphine (199) and its sulfide (200) appeared to interact with borane under mild conditions, yielding a new type of phosphorus-boron-containing heterocycle—2-... 

Organic constituents that may be found in ppb levels in WP/F smoke include methane, ethylene, carbonyl sulfide, acetylene, 1,4-dicyanobenzene, 1,3-dicyanobenzene, 1,2-dicyanobenzene, acetonitrile, and acrylonitrile (Tolle et al. 1988). Since white phosphorus contains boron, silicon, calcium, aluminum, iron, and arsenic in excess of 10 ppm as impurities (Berkowitz et al. 1981), WP/F smoke also contains these elements and possibly their oxidation products. The physical properties of a few major compounds that may be important for determining the fate of WP/F smoke in the environment are given in Table 3-3. 

X-ray Photoelectron Spectroscopy (XPS) tests were conducted on surfaces lubricated with a sulfur-containing extreme pressure additive, dibenzyl sulfide (Baldwin, 1976 Bird and Galvin, 1976). The films can arise from the use of additives that contain sulfur, phosphorus, chlorine, bromine, or boron and the differences in reactivity are affected by the formation of protective layers. Triboinduced electrons are said to activate the formation of iron halides, iron phosphates and iron sulfides (Dorison and Ludema, 1985 Grunberg, 1966 Kajdas, 2001 McFadden et al., 1998 ). When a chemical reaction takes place, e.g., oxygen interacts with aluminum to form aluminum oxide, a large oxygen peak is seen at approximately 500 eV in the Auger electron spectra (Benndorf et al., 1977 Nakayama et al., 1995). 

The chemical form and nature of the element. Most trace metal cations have a low mobility in soils because they adsorb strongly on minerals and organic matter, or form insoluble precipitates (e.g., oxides, carbonates, sulfides). Some elements that take the form of anions in soils, such as boron, are relatively mobile. Other elements that form anions, like phosphorus, are considered to be immobile because they form insoluble precipitates and bond strongly with mineral surfaces. In Figure 9.4, many of the elements of interest in soils are classified on the basis of their ionic radii and valence. The elements tend to fall naturally into one of foiu groups ... 

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