Phosphorus bases

Other phosphorus-based polymers have been investigated and have proved to be of some interest. An example is phosphorus oxynitride, which forms a glass above 1000°C. 

One can extend the strategy employed in the Reissert-Henze reaction to nucleophiles other than cyanide. Phosphorus-based systems were employed in the... 

Phosphor-athcr, m. phosphoric ether (ester of phosphoric acid, specif, ethyl phosphate), -basis, phosphorus base, -bestimmung, /. determination of phosphorus, -blei, n. lead phosphide Min.) pyromorphite. -bombe, f. phosphorus bomb. -brandgranate, /. phosphorus incendiary shell, -brei, m. phosphorus paste, -bromid, n. phosphorus bromide, specif, phosphorus pentabromide, phos-phorus(V) bromide, -bromijr, n. phosphorus tribromide, phosphorus(III) bromide, -bronze, /. phosphor bronze, -calcium, n. calcium phosphide, -chlorid, n. phosphorus chloride, specif, phosphorus pcntachloride, phosphorus(V) chloride, -chloriir, n. phosphorous chloride (phosphorus trichloride, phosphorus(III) chloride), -dampf, tn. phosphorus vapor or fume, -eisen, n. ferrophos-phorus iron phosphide, -eisensinter, m. diadochite. 

More recently there have been developed water- resistant phosphorus-based intumescence catalyst. This commercially available product, as an example Phos-Chek P/30 tradename from Monsanto, can be incorporated (with other water insoluble reagents) into water-resistant intumescent coatings of either the alkyd or latex-emulsion type. These intumescent coatings, formulated ac-... 

The mode of action of phosphorus-based flame retardants is believed to take place in either the condensed or the vapor phase (refs. 1,2) depending on the type of phosphorus compound and the chemical composition of the polymer. Phosphorus has been reported to be 3 to 8 times more effective than bromine depending on the polymer type (ref. 3). 

Substance TBBA replaces PBB/PBDE Polymerized TBBA Phosphorus-based retardants Mineral-based retardants Change base material Separate high and low voltage Reduce voltage... 

The key to the successful development of homogeneous catalysts has been the exploitation of the effects that ligands exert on the properties of metal complexes by tailoring the electronic and steric properties of a catalytically active metal complex, activities and selectivities can be altered considerably. This especially holds for phosphorus based ligands, which are the most commonly encountered ligands as.sociated with organometallic compounds. 

Macrolides and Related Compounds.- Phosphorus-based methods have... 

Kapustin GV, Fejer G, Gronlund JL, Mccafferty DG, Seto E, Etzkorn FA (2003) Phosphorus-based saha analogues as histone deacetylase inhibitors. Org Lett 5 3053-3056... 

One of the chief defects of the phosphorus based pyrazolyl (PZ) ligands appears to be the hydrolytic sensitivity of the P—N bond particularly after interaction of the ligand with transition metal ions. The interactions of PhP(0)(3,5-Me2pz)2 and Ph2P(0)(3,5-Me2pz)2 with Pd11 salts accelerates the P—N bond hydrolysis.177... 

When used purely as an insulator, foam densities can be as low as 0.02 to 0.08 g/cm3. In structural applications the foam s density can rise to 0.4 to 0.7 g/cm3. The use of fluorocarbons as blowing agents has largely given way to more environmentally friendly agents, such as low molecular weight hydrocarbons. We can impart flame retardancy by incorporating chlorine-or phosphorus-based compounds. 

Dubois et al. [184] reported the synthesis of phosphorus based dendrimers terminated with multivalent palladium complexes. Iterative free radical addition... 

Silicon and phosphorus generally form rather weak bonds, consequently in phosphorus chemistry, silyl substituents are mainly used as a leaving group. In silicon chemistry, phosphorus-based substituents are less common, though this has changed in the last two decades due to novel concepts in molecular chemistry (prominent examples are [/BuSi-P]4 [1] and R2Si=PR [2]) and in materials sciences. 

A very special class of phosphorus based ligands are ambidentate, anionic phosphinomethanides I, since, due to the same number of valence electrons and bonds, both phosphorus and carbon are comparable in their reactivity and may compete for electrophiles. 

In the second instance, two approaches seem to be worthy of special note. The synthetic utility of elemental phosphorus based on it acting as a radical trap appears to be quite valuable, but additional effort is required to determine the variability of the source of the organic free radicals. (Is there some other, more efficacious, source of organic free radicals that works better with this system than acylated iV-hydroxy-2-pyridones ) The other approach that appears ripe for development is the hydrolysis/elimination with "phosphorates" derived from the oxidative addition of white phosphorus to alkenes. We look forward to the continued development of such facile approaches toward the preparation of fundamental phosphonic acids. 

In fact, a single series of phosphorus-based heterocyclic compounds, l,3-azaphospholo[5,l- ]isoquinolines (435 X = P), was reported together with their preparation through 1,5-electrocyclization of bis-(A-pyridinium ylidyl)phos-phenium chlorides 437, as shown in Scheme 113 <1999TL1565>. 

In 1975, Hendrickson and Schwartzman reported a different mode of phosphorus-based hydroxyl activation using bis(phosphonium) electrophiles (R3P—O—PR3)2+. These highly reactive electrophiles are generated from the reagent combination of phosphine oxide and trifluoromethanesulfonic (triflic) anhydride [96]. Mukaiyama... 

Phosphorus-Based Ligands in the Catalyzed Addition of Grignard Reagents... 

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