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Phosphonic Acid (phosphonic + acid)

Distribution by Scientific Domains

Chemistry	50%
Polymers and Materials Science	33%
Life Sciences	12%

Selected Abstracts

Radical Telomerisation of Vinyl Phosphonic Acid with a Series of Chain Transfer Agents

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 6 2007
Ghislain David
Abstract The use of CTAs for the radical polymerisation of VPA has been successfully applied for the first time. Several CTAs were investigated, including thiol, disulfide and halogenated compounds. The use of mercaptoacetic acid led to the synthesis of the mercaptan VPA monoadduct, which was attributed to a high transfer constant (CT,=,ktr/kp) of approximately 7. Transfer reactions with VPA appeared to be unsuccessful when using benzyldisulfide, 1,1,1-trichloroethane and trichloroacetic acid. Application of bromotrichloromethane as a transfer agent led to the oligomerisation of VPA, with final conversion being approximately 80%. The transfer events were characterised by 13C NMR, MALDI-TOF and elemental analysis. Molecular weights of the successful VPA polymerisations showed values ranging from 600 to 5,000 g,·,mol,1, which were in close agreement with the theoretically calculated values. [source]

Kinetics of Solvent Extraction of Copper(II) by Bis-(2,4,4-Trimethylpentyl)Phosphonic Acid using a Single Drop Technique

CHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 9 2007
K. Biswas
No abstract is available for this article. [source]

Phosphonic acid functionalized polyethylene glycol and derivatives

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008
Mohamed Essahli
Abstract This article describes the functionalization of polyethylene glycol, mono or bifunctional, and a nonionic surfactant by phosphonic acids without the need for protection of the functional group. The functionalization is performed in two steps, first an esterification by thioglycolic acid, secondly a radical addition of vinyl phosphonic acid on the thiol group. All products were obtained quantitatively and characterized by 1H-, 13C-, 31P-NMR spectroscopy techniques, MALDI, and step-by-step chemical titrations. Enhanced thermal properties were found while phosphonylating polyethylene glycol, particularly when the sulfur atom was oxidized into a sulfone group. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

Molecular Dynamics Simulation of Interaction between Calcite Crystal and Phosphonic Acid Molecules

CHINESE JOURNAL OF CHEMISTRY, Issue 3 2010
Jianping Zeng
Abstract The interactions between calcite crystal and seven kinds of phosphonic acids, nitrilotris(methylphosphonic acid) (NTMP), nitrilo-methyl-bis(methylphosphonic acid) (NMBMP), N,N -glycine-bis(methylphosphonic acid) (GBMP), 1- hydroxy-1,1-ethylenebis(phosphonic acid) (HEBP), 1-amino-1,1-ethylenebis(phosphonic acid) (AEBP), 1,2-ethylenediamine- N,N,N,,N, -tetrakis(methylphosphonic acid) (EDATMP), and 1,6-hexylenediamine- N,N,N,,N, -tetrakis- (methylphosphonic acid) (HDATMP) have been simulated by a molecular dynamics method. The results showed that the binding energy of each scale inhibitor with the (1l,0) (1l,0) face of calcite crystal was higher than that with (104) face, which has been approved by the analysis of pair correlation functions. The sequence of scale inhibition efficiencies for phosphonic acids against calcite scale is as follows: EDATMP>HDATMP>HEBP>NTMP>GBMP>HEBP>NMBMP, and the growth inhibition on the (1l,0) face of calcite was at the leading status. Phosphonic acids deformed during the binding process, and electrovalent bonds formed between the phosphoryl oxygen atoms in phosphonic acids and the calcium ions on calcite crystal. [source]

Two- and Three-Dimensional Hydrogen-Bonded Networks Built from 1,3,5-[(HO)2(O)P]3C6H3 and 4-(Dimethylamino)pyridine

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 16 2004
Michael Mehring
Abstract Crystallisation of 3,5-bis(phosphonophenyl)phosphonic acid, 1,3,5-[(HO)2(O)P]3C6H3, from MeOH/H2O in the presence of 4-(dimethylamino)pyridine, 4-(Me2N)C5H4N, gave [1-{(HO)2(O)P}-3,5-{(HO)(O)2P}2C6H3]2,[{4-(Me2N)C5H4NH}+]2 (2) and [1,3-{(HO)2(O)P}2 -5-{(HO)(O)2P}C6H3],[4-(Me2N)C5H4NH]+ (3). Single-crystal X-ray diffraction analyses revealed a two- and a three-dimensional hydrogen-bonded network for compounds 2 and 3, respectively. Compound 2 is composed of layers which are formed by hydrogen-bonded motifs of the type R2,2(8) and R4,4(16). These motifs are connected within the layer by additional hydrogen bonds and the benzene spacer. The cation [4-(Me2N)C5H4NH]+ is located between the layers and determines the interlayer separation of approximately 6.5 Å. In compound 3 a layered network of the hydrogen-bonded building units R2,3(10) was observed. These units are interconnected by four additional hydrogen bonds within the network. The benzene spacer links the adjacent layers to give a three-dimensional structure. Within this network, channels with internal dimensions of ca. 8.5 × 11.3 Å2 which are occupied by the [4-(Me2N)C5H4NH]+ cations were observed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

Chemical Bonding Assembly of Multifunctional Oxide Nanocomposites

ADVANCED FUNCTIONAL MATERIALS, Issue 2 2010
Gary Evans
Abstract The synthesis, functionalization and assembly of metal oxide nanoparticles BaTiO3 and CoFe2O4 is presented. The ferroelectric (BaTiO3) and ferromagnetic (CoFe2O4) oxide nanoparticle surfaces are directly functionalized via the anchoring of phosphonic acid and aminosilane molecules that engender the nanoparticles with terminal carboxylic acid and amine functional groups, respectively. These promote the electrostatic self-assembly of the particles in non-polar solvents and permit the synthesis of more chemically robust assemblies linked by the covalent amide bond via the addition of the chemical coupling agent N - N, -dicyclohexylcarbodiimide. This functionalization and assembly procedure is applied to two systems: the first comprised of 50,nm BaTiO3 and 10,nm CoFe2O4 particles and the second of 200,nm BaTiO3 and 12.5,nm CoFe2O4 particles. The latter composites possess magnetoelectric properties when processed into dense ceramics and, as a direct result of the assembly performed in solution, have a high degree of homogeneity between the ferroelectric and ferromagnetic phases. The developed functionalization and assembly procedure is considered to be adaptable to the preparation of other hybrid oxide nanomaterials with different property combinations. [source]

Phosphonic acid functionalized polyethylene glycol and derivatives

Calcium phosphate formation on the phosphorylated dental bonding agent in electrolyte solution

JOURNAL OF ORAL REHABILITATION, Issue 1 2004
T. Hayakawa
summary, The aim of the present study was to study the mineral formation on a phosphorylated dental bonding agent using a mineralization inductive solution. Clearfil Photobond, which contained phosphate monomer, was cured by photo-irradiation and heat treated, and was then immersed in Hanks' balanced salt solution (HBSS) with pH = 7·4 for 1, 3, 5, 7, 14, and 28 days at 37 °C. The white substances were deposited on the phosphorylated polymer, i.e. cured Photobond disk, after the immersion in HBSS. The white substances become visible after 3 days immersion. After 7 days immersion, surface of the phosphorylated polymer disk was almost covered with white substance layers. The measurement of white substances by means of X-ray diffraction, Fourier-transform infrared and electron probe microanalysis revealed that their main component was carbonate-containing hydroxyapatite. Scanning electron microscopy pictures showed that a large number of globules of hydroxyapatite were fused together, and that each globule was composed of a group of numerous thin-film form flakes uniting and/or clustering together. The results obtained in this study concluded that the presence of phosphonic acid and phosphate group of phosphorylated dental bonding agent enhanced the nucleation and growth of hydroxyapatite crystals on its surface. [source]

1H, 13C and 31P NMR spectral analysis of monoalkyl (,-anilinobenzyl)phosphonates and their dipalladium(II) metallocyclic complexes

MAGNETIC RESONANCE IN CHEMISTRY, Issue 3 2002
Ljerka Tu, ek-Bo
Abstract A 1H, 13C and 31P NMR study of monoethyl (HL1) and monobutyl (HL2) esters of (,-anilinobenzyl)phosphonic acid and their metallocyclic dipalladium complexes (Pd2L4,L = L1, L2) in DMSO- d6 was performed, based on 1D and 2D homo- and heteronuclear experiments including 1H,13C,31P,APT,1H,1H COSY, 1H,13C COSY, gs-HMQC and gs-HMBC NMR techniques. The results obtained are discussed with respect to those for some palladium(II) complexes reported for various anilinobenzylphosphonate derivatives. Copyright © 2002 John Wiley & Sons, Ltd. [source]

The application of ethephon (an ethylene releaser) increases growth, photosynthesis and nitrogen accumulation in mustard (Brassica juncea L.) under high nitrogen levels

PLANT BIOLOGY, Issue 5 2008
N. A. Khan
Abstract Ethephon (2-chloroethyl phosphonic acid), an ethylene-releasing compound, influences growth and photosynthesis of mustard (Brassica juncea L. Czern & Coss.). We show the effect of nitrogen availability on ethylene evolution and how this affects growth, photosynthesis and nitrogen accumulation. Ethylene evolution in the control with low N (100 mg N kg,1 soil) was two-times higher than with high N (200 mg N kg,1 soil). The application of 100,400 ,l·l,1 ethephon post-flowering, i.e. 60 days after sowing, on plants receiving low or high N further increased ethylene evolution. Leaf area, relative growth rate (RGR), photosynthesis, leaf nitrate reductase (NR) activity and leaf N reached a maximum with application of 200 ,l·l,1 ethephon and high N. The results suggest that the application of ethephon influences growth, photosynthesis and N accumulation, depending on the amount of nitrogen in the soil. [source]

Efficacy of phosphonic acid, metalaxyl-M and copper hydroxide against Phytophthora ramorum in vitro and in planta

PLANT PATHOLOGY, Issue 1 2009
M. Garbelotto
The ability of metalaxyl-M, phosphonic acid in the form of phosphonate, and copper hydroxide to inhibit different stages in the life cycle of Phytophthora ramorum, the causal agent of sudden oak death (SOD), was tested in vitro using 12 isolates from the North American forest lineage. In addition, experiments were conducted in planta to study the ability of phosphonic acid injections and metalaxyl-M drenches to control pathogen growth on saplings of California coast live oak (Quercus agrifolia), and of copper hydroxide foliar sprays to control infection of California bay laurel (Umbellularia californica) leaves. Phytophthora ramorum was only moderately sensitive to phosphonic acid in vitro, but was highly sensitive to copper hydroxide. In planta experiments indicated the broad efficacy of phosphonic acid injections and of copper hydroxide sprays in preventing growth of P. ramorum in oaks and bay laurels, respectively. Finally, although metalaxyl-M was effective in vitro, drenches of potted oak trees using this active ingredient were largely ineffective in reducing the growth rate of the pathogen in planta. [source]

Conformational isomers of the [(5-methyl-2-pyridinio)aminomethylene]diphosphonate dianion and [(5-methyl-2-pyridyl)aminomethylene]diphosphonate trianion in salts with 4-aminopyridine and ammonia

ACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2009
Ewa Matczak-Jon
The crystal structures of two salts, products of the reactions between [(5-methyl-2-pyridyl)aminomethylene]bis(phosphonic acid) and 4-aminopyridine or ammonia, namely bis(4-aminopyridinium) hydrogen [(5-methyl-2-pyridinio)aminomethylene]diphosphonate 2.4-hydrate, 2C5H7N2+·C7H10N2O6P22,·2.4H2O, (I), and triammonium hydrogen [(5-methyl-2-pyridyl)aminomethylene]diphosphonate monohydrate, 3NH4+·C7H9N2O6P23,·H2O, (II), have been determined. In (I), the Z configuration of the ring N,C and amino N,H bonds of the bisphosphonate dianion with respect to the Cring,Namino bond is consistent with that of the parent zwitterion. Removing the H atom from the pyridyl N atom results in the opposite E configuration of the bisphosphonate trianion in (II). Compound (I) exhibits a three-dimensional hydrogen-bonded network, in which 4-aminopyridinium cations and water molecules are joined to ribbons composed of anionic dimers linked by O,H...O and N,H...O hydrogen bonds. The supramolecular motif resulting from a combination of these three interactions is a common phenomenon in crystals of all of the Z -isomeric zwitterions of 4- and 5-substituted (2-pyridylaminomethylene)bis(phosphonic acid)s studied to date. In (II), ammonium cations and water molecules are linked to chains of trianions, resulting in the formation of double layers. [source]

A HTS Assay for the Detection of Organophosphorus Nerve Agent Scavengers

CHEMISTRY - A EUROPEAN JOURNAL, Issue 11 2010
Ludivine Louise-Leriche
Abstract A new pro-fluorescent probe aimed at a HTS assay of scavengers is able to selectively and efficiently cleave the PS bond of organophosphorus nerve agents and by this provides non-toxic phosphonic acid has been designed and synthesised. The previously described pro-fluorescent probes were based on a conventional activated POaryl bond cleavage, whereas our approach uses a self-immolative linker strategy that allows the detection of phosphonothioase activity with respect to a non-activated PSalkyl bond. Further, we have also developed and optimised a high-throughput screening assay for the selection of decontaminants (chemical or biochemical scavengers) that could efficiently hydrolyse highly toxic V -type nerve agents. A preliminary screening, realised on a small ,-nucleophile library, allowed us to identify some preliminary "hits", among which pyridinealdoximes, ,-oxo oximes, hydroxamic acids and, less active but more original, amidoximes were the most promising. Their selective phosphonothioase activity has been further confirmed by using PhX as the substrate, and thus they offer new perspectives for the synthesis of more potent V nerve agent scavengers. [source]

Tailored Control and Optimisation of the Number of Phosphonic Acid Termini on Phosphorus-Containing Dendrimers for the Ex-Vivo Activation of Human Monocytes

CHEMISTRY - A EUROPEAN JOURNAL, Issue 16 2008
Olivier Rolland
Abstract The syntheses of a series of phosphonic acid-capped dendrimers is described. This collection is based on a unique set of dendritic structural parameters,cyclo(triphosphazene) core, benzylhydrazone branches and phosphonic acid surface,and was designed to study the influence of phosphonate (phosphonic acid) surface loading towards the activation of human monocytes ex vivo. Starting from the versatile hexachloro-cyclo(triphosphazene) N3P3Cl6, six first-generation dendrimers were obtained, bearing one to six full branches, that lead to 4, 8, 12, 16, 20 and 24 phosphonate termini, respectively. The surface loading was also explored at the limit of dense packing by means of a first-generation dendrimer having a cyclo(tetraphosphazene) core and bearing 32 termini, and with a first-generation dendrimer based on a AB2/CD5 growing pattern and bearing 60 termini. Human monocyte activation by these dendrimers confirms the requirement of the whole dendritic structure for bioactivity and identifies the dendrimer bearing four branches, thus 16 phosphonate termini, as the most bioactive. [source]

Molecular Dynamics Simulation of Interaction between Calcite Crystal and Phosphonic Acid Molecules

Novel and Convenient Approach to Synthesis of AZT/d4T H-phosphonates

CHINESE JOURNAL OF CHEMISTRY, Issue 3 2004
Chang-Xue Lin
Abstract A convenient, efficient and general method has been developed for synthesis of H-phosphonate mono and diesters of AZT and d4T through one-pot reaction of phosphonic acid with AZT or d4T and different alcohols using pivaloyl chloride as condensing agent under mild conditions. [source]

Green, Palladium-Catalyzed Synthesis of Benzylic H -Phosphinates from Hypophosphorous Acid and Benzylic Alcohols

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 24 2008
Laëtitia Coudray
Abstract Benzylic alcohols cross-couple directly with concentrated H3PO2 by using Pd/xantphos (1 or 2 mol-%). Depending on the substrate, DMF at 110 °C or t -AmOH at reflux with a Dean,Stark trap can be used. A broad range of benzylic alcohols react successfully to give moderate to good yields of the products. The preparation of other organophosphorus compounds (phosphinic and phosphonic acids) is also demonstrated. Asymmetric reaction with (R)-1-(2-naphthyl)ethanol provids the corresponding H -phosphinic acid in 77,% ee. The methodology provides a green, PCl3 -free route to benzylic- H -phosphinic acids.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Synthesis and Molecular Structure of New Unsaturated Analogues of Nucleotides Containing Six-Membered Rings

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 3 2005
Valery K. Brel
Abstract The reaction of 1-(chloromethyl)-3-(diethoxyphosphonyl)allenes 15 and 16 with purine and pyrimidine bases in the presence of cesium carbonate afforded new acyclic analogs of nucleotides containing a 1,2-alkadienic skeleton (17,24). Intramolecular cyclization of the alkoxides tethered to the allenyl moiety yielded dihydropyrans 33,38 and dihydrofurans 39 and 40. Dealkylation of the dihydropyrans led to the corresponding phosphonic acids. The molecular structures of new nucleotide analogs 33 and 36 were determined by single-crystal X-ray analyses. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]

Phosphonic acid functionalized polyethylene glycol and derivatives

Synthesis and stability study of dental monomers containing methacrylamidoethyl phosphonic acids

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 1 2007
Xiaoming Xu
Abstract Three new dental monomers containing methacrylamidoethyl phosphonic acids were synthesized. The structures of the synthesized monomers were determined with electrospray mass spectrometry (ESMS), Fourier transform infrared, and NMR. The hydrolytic stabilities of the synthesized monomers and a commercial monomer, 2-methacryloyloxyethyl phosphoric acid (MEP; used as a control), were studied with flow injection (FI)/ESMS, 1H NMR, and 31P NMR analysis of a CD3OD/D2O (4:1 v/v) solution of each monomer before and after storage at 60 °C for 2 months. The 1H NMR and 31P NMR chemical shifts of the monomers 2-methacrylamidoethylphosphonic acid (I) and N,N,-[4,4,-(propane-2,2-diyl)-bis(phenoxy-2-hydroxypropyl)]-bis(2-methacrylamidoethylphosphonic acid) (II) showed little change after storage at 60 °C for 2 months, but those of MEP changed significantly. FI/ESMS also showed that MEP was nearly completely decomposed, whereas monomers I and II remained largely intact. MEP could react with H2ZrF6 to form ternary zirconium fluoride complexes that were partially soluble in methanol, but all the monomers containing phosphonic acids formed precipitates. This study demonstrates that ESMS is a more sensitive and effective method than NMR for studying the hydrolytic stability or degradation of dental monomers. The new monomers containing methacrylamidoethyl phosphonic acids have higher hydrolytic stability than methacrylate phosphate monomers and may be used in dental bonding agents and other dental materials. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 99,110, 2007 [source]