Phosphorus surface chemistry

Kopping JT, Patten TE (2008) Identification of acidic phosphorus-containing ligands involved in the surface chemistry of CdSe nanoparticles prepared in tri-n-octylphosphine oxide solvents. J Am Chem Soc 130 5689-5698... 

The NPD is similar in design to the FID (flame ionization detector), except that the hydrogen flow rate is reduced to about 3 mL/min, and an electrically heated thermionic bead (NPD bead) is positioned near the column orifice. Nitrogen or phosphorus containing molecules exiting the column collide with the hot bead and undergo a catalytic surface chemistry reaction. The resulting ions are attracted to a collector electrode, amplified, and output to the data system. The NPD is 10-100 times more sensitive than FID. 

Trimethylphosphine. Trimethylphosphine is very strongly chemisorbed on all the nickel surfaces. On the Ni(lll) surface, thermal decomposition occurs readily and CHi, and H2 are desorbed as decomposition products with desorption maxima at 90 and 98°C respectively. Chemisorption of this phosphine initially must involve a donor-acceptor interaction centered at the phosphorus atom. Models show that the methyl hydrogen atoms can then closely approach the surface metal atoms. Cleavage of C-H bonds probably occurs at or near 25°C, and P-C-Ni bonds are then irreversibly formed. This surface chemistry qualitatively mirrors that of trimethylphosphine in the coordinately unsaturated complex, Fe[P(CH3)3K, which is primarily HFe[r)2-CH2P(CH3)i][P(CH3)3]3 in the solution state (21). 

Understanding the surface chemistry for supported vanadium oxide systems modified with phosphorus oxide at hydrocarbons oxidation... 

Williams, P.M., 1967. Sea surface chemistry organic carbon, nitrogen and phosphorus in surface films and subsurface waters. Deep-Sea Res., 14 791—800. 

Besides C, the spectra of [118, 280] and b [281] were found as useftil to study the changes in surface chemistry and heteroatom arrangements present on the carbon surface. Especially valuable for this purpose is phosphorus. Large chemical shift for P allows to easy distinguish between various phosphorous containing compounds present on the carbon surface. The study of chemical shift for B was foimd to be extremely useful to evaluate the incorporation of boron atoms to the carbon structure and boron atoms environment (boron to boron connected configurations or isolated boron atoms) [281]. 

The only element that was discovered in body fluids (urine). This is plausible, as P plays a main role in all life processes. It is one of the five elements that make up DNA (besides C, H, N, and 0 evolution did not require anything else to code all life). The P-O-P bond, phosphoric acid anhydride, is the universal energy currency in cells. The skeletons of mammals consists of Ca phosphate (hydroxylapatite). The element is encountered in several allotropic modifications white phosphorus (soft, pyrophoric P4, very toxic), red phosphorus (nontoxic, used to make the striking surface of matchboxes), black phosphorus (formed under high pressures). Phosphates are indispensable as fertilizer, but less desirable in washing agents as the waste water is too concentrated with this substance (eutrophication). It has a rich chemistry, is the basis for powerful insecticides, but also for warfare agents. A versatile element. 

Kirchherg, H., and Wottgen, L., The Effect of Phosphorus and Antimony Surfactants on Cassiterite Flotation, Chemistry, Physics and Application of Surface Active Substances, London, pp. 693-704, 1976. 

Table 8.30 shows the chemistry of seawater compiled by Turekian (1969) for major, minor, and trace constituents, expressed in parts per billion (ppb) at a mean salinity of 35. The listed values are estimates of mean amounts in solution, whereas elemental concentrations actually vary with depth. The most conspicuous variations are observed in the first 200 m from the surface, where photosynthetic processes are dominant and phosphorus and nitrogen are fixed by plankton and benthos, as well as silica and calcium, which constitute, respectively, the skeletons of planktonic algae (diatom) and the shells of foraminifera and mollusks. 

Figure 6. Canonical correspondence analysis for surface sediments of 41 lakes in British Columbia, Canada, that encompass a broad range of trophic states. Circles represent lakes and triangles represent the 25 most abundant diatom taxa. Arrows indicate environmental variables that correlate most strongly with the distribution of diatom taxa and lake-water chemistry, as detected by forward selection. Maximum depth (Zntax) and total phosphorus (TP) were transformed by using the In (x + 1) function. This analysis is discussed in detail in reference 46.

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