Phosphonic acid-based chemicals

Phosphonic acid-based chemicals are known to form complexes with many inorganic species, and the action of many retarders is based on complex formation. Several phosphonic acids such as amino trimethylene phosphonic acid (ATMP), 1-hydroxyethylidene-l, 1-diphosphonic acid... 

Phosphonic acid-based chemicals such as ATMP, HEDP, DTMP, and their sodium salts were added to portland cement in dosages of 0.03-0.09% at a constant w/c ratio of 0.35 and their conduction calorimetric and DSC curves were compared. The conduction calorimetric curves... 

Figure 18 Chemical structures of phosphonic acid-based bisubstrate analog inhibitors of farnesyl transferase.

Organophosphoms compounds, primarily phosphonic acids, are used as sequestrants, scale inhibitors, deflocculants, or ion-control agents in oil wells, cooling-tower waters, and boiler-feed waters. Organophosphates are also used as plasticizers and flame retardants in plastics and elastomers, which accounted for 22% of PCl consumed. Phosphites, in conjunction with Hquid mixed metals, such as calcium—zinc and barium—cadmium heat stabilizers, function as antioxidants and stabilizer adjutants. In 1992, such phosphoms-based chemicals amounted to slightly more than 6% of all such plastic additives and represented 8500 t of phosphoms. Because PVC production is expected to increase, the use of phosphoms additive should increase 3% aimually through 1999. 

Steininger, H., Schuster, M., Kreuer, K. D., Kaltbeitzel, A., Bingol, B., Meyer, W. H., Schauff, S., Brunklaus, G., Maier, J. and Spiess, H. W. 2007. Intermediate temperature proton conductors for PEM fuel cells based on phosphonic acid as protogenic group A progress report. Physical Chemistry Chemical Physics 9 1764-1773. 

The development of new families of high-stress tolerant, polymer-phosphonate-based chemical inhibitor programs, that now permit operators of small cooling systems to run at high cycles and alkalinity, with no sulfuric acid, has almost eliminated the risk of accidental calcium sulfate deposition in these systems. 

The CPSC staff performed quantitative risk assessments on various flame-retardants for both upholstered residential furniture fabrics and foam.89 CPSC addresses chemical hazards under the Federal Hazardous Substances Act (FHSA), which is risk based. For fabrics, five flame-retardants were evaluated, that include antimony trioxide, deca-BDE, HBCD, phosphonic acid, (3- [hydroxymethyl]amino)-3-oxopropyl)-, dimethyl ester (PA), and tetrakis (hydroxymethyl) phosphonium chloride (THPC). These flame-retardants were selected for study because they are used to comply with the U.K. upholstered furniture flammability standard (except THPC) and fabric samples were available for testing. The staff concluded in 2006 that deca-BDE, HBCD, and PA would not present a hazard to consumers and that additional data would be needed to assess antimony trioxide and THPC. 

The phosphorylation of phenol-furfural condensate affords a cation-exchange resin with improved thermal and chemical reristance. The heat treatment of phosphonic add resins from furfural redns, phenol-resorcinol-formaldehyde resin, and polystyrene at 100-180 °C for 10-48 h shows that the furfural-based phosphonic acid resins possess higher thermal stability than those from the other two polymers. 

One feasible method for the exploration of chiral open-framework compounds is the use of chiral chemical units as primary building blocks by coordinating with metal or other assembly methods to form 2-D layer or 3-D open-framework structures with optical activity. A notable example is the enantiomerically pure zinc phosphonate based on a mixed phosphonic acid-phosphine oxide chiral building block reported by Bujoli and coworkers in 2001.[91] The reaction procedures are shown as follows. 

The aromatic nuclei of PBl are responsible of its good characteristics of chemical stability, whereas the basic functional groups act as proton acceptors like a normal acid-base reaction. Amphoteric acids, such as phosphoric or phosphonic... 

A very exciting in vivo application is the development of paramagnetic complexes as novel NMR pH indicators. The system is based on the remarkable pH dependence of the chemical shift separation (7.0+0.1 ppm/pH unit) observed between the outer H NMR resonances on the spectrum of the ytterbium complex, [Yb(dotp)] (14) in the pH range 5.0 - 7.5 at 39 °C, where Hgdotp represents 1,4,7,10-tetraazacyclododecane-N,N, N",N" -tetrakis-(methy-lene-phosphonic acid). 

The P-H group of diesters of H-phosphonic acid is highly reactive and participates in a variety of chemical reactions such as oxidation, addition to C=C double bond, C=N (Schiff bases), ketones, isocyanates, and condensation reactions. 

The following chapters are devoted to applications of phosphorus-based materials. Thus Chapter 8 by Mozsner and Catel deals with the use of polymerizable phosphonic acids (PAs) and dihydrogen phosphates (DHPs) for dental applications. Several PAs and DHPs were synthesized to notably improve the shear bond strength to dentin and enamel, the stability of the adhesive formulation, and the chemical adhesion to tooth tissues. Some of these monomers are nowadays included in commercial dental adhesives. 

The ultimate goal of this project is to design enzyme-based PL PSi detectors for toxic chemical detection therefore, the selection of enzymes active towards these types of target molecules is critical. Table I shows activity parameters of some enzymes in solution that have hydrolysis activity toward G-type nerve agents. OPAA-2 was selected for immobilization because it has relatively high activity towards GB and GD, as well as towards surrogates such as DFP, and /7-nitro-phenyl-soman (20-23). The products from the enzymatic action would be a phosphonic acid and HF. 

Herbicides are used in many different forms. There are herbicides that are active against all herbs, vhile others show herb-selective action. Herbicides can be taken-up by the plant via roots or via leaves. Important chemical classes of herbicides are carbonic acid based, urea based, aniline based, and phosphonic or phosphoric acid based. The aniline-based herbicide (Sj-metolachlor is shown as example in Table 5.3.19. This herbicide is used in corn farming and is one of the most important examples of products industrially synthesized by asymmetric synthesis using a chiral transition metal complex. The asymmetric synthesis was established after it was discovered that almost all the activity (95%) is caused by the (Sj-metolachlor stereoisomer. 

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