Littérature scientifique sur le sujet « Bis-phosphonic acids »

Polynuclear copper(II) derivatives of 1-hydroxyethylidenediphosphonic acid (HEDP), 1-aminoethylidenediphosphonic acid (AEDP, H4L),α-aminobenzylidene diphosphonic acid (ABDP, H4L), 1-amino-2-carboxyethane- 1,1-diphosphonic acid (ACEDP, H5L), 1,3 diaminopropane-1,1,3,3-tetra-phosphonic acid (DAPTP, H8L), Ethylenediamine-N,N'-bis (dimethyl-methylenephosphonic) acid (EDBDMPO, H4L),o-phenylene-diamine-N,N'-bis (dimethylmethylenephosphonic) acid (PDBDMPO, H4L), diethylene triamine –N,N,N',N',N"N-penta (methylene phosphonic) acid (DETAPMPO, H10L) and diethylene triamine –N,N"-bis (dimethyl methylene phosphonic) acid (DETBDMPO, H4L) have been prepared in aqueous medium. The general formula of derivatives from elemental analysis was found to be Cu2L.XH2O (in case of AEDP, ABDP, EDBDMPO, PDBDMPO, DETBDMPO), Cu5L2.XH2O (in case of ACEDP) Cu4L.XH2O, Cu2H4L. XH2O (in case of DAPTP) and Cu5L.XH2O (in case of DETAPMPO). The electronic spectra have shown them to be six coordinated with slight distortion from octahedral geometry. Antiferromagnetism was inferred from magnetic moment data. Infrared spectral studies were carried out to determine coordination sites. EPR (Electron Paramagnetic Resonance) spectra that supports the presence of tetragonal distortion and antiferromagnetic behaviour, have also been studied.

Available experimental data on stability constants of proton and metal complexes for 10 phosphonic acids [methylphosphonic acid, 1-hydroxyethane-1,1-diylbisphosphonic acid, dichloromethylenebisphosphonic acid, amino-methanephosphonic acid, N-(phosphonomethyl)glycine, imino-N,N-bis(methylenephosphonic acid), N-methylamino-N,N-bis(methylenephosphonic acid), nitrilotris(methylenephosphonic acid), 1,2-diaminoethane-N,N,N´,N´-tetrakis-(methylenephosphonic acid), and diethylenetriamine-N,N,N´,N´´,N´´-pentakis-(methylenephosphonic acid)], published in 1950­1997, have been critically evaluated. For the latter phosphonate, all the data are rejected, as well as protonation constants [HL]/[H][L] for three other ligands. Higher-quality data are selected and presented as "Recommended" and "Provisional".

Host-Guest complexation of calixarene-bis-hydroxymethylenediphosphonic acid with 17 amino acids in water solution had been studied by the RP HPLC and molecular modelling methods. It had been shown the binding constants of the complexes are depended on the nature of the amino acid residue, log P and pKa of the acids. The complexation is mainly determined by the electrostatic interactions between the positively charged nitrogen atom of the amino acid and the negatively charged oxygen atom of phosphonic acid residue of the calixarene, the Host-Guest p-p, СН-p and solvophobic interactions.

We report here a general method for the synthesis of new symmetrical bis-phosphonates of acyclic nucleosides. 1,3-Bis[(diisopropoxyphosphoryl)methoxy] derivatives of purine and pyrimidine bases were prepared by their reaction with 1,3-bis[(diisopropoxyphosphoryl)-methoxy]propan-2-yl tosylate. Cytosine, uracil and thymine provided regiospecificallyN1-isomers. This alkylation regiospecificity applies to several other tosylates of primary and secondary alcohols as well. 6-Chloropurine and 2-amino-6-chloropurine were alkylated in N9position. Resulting bis-phosphonates were converted to the respective free phosphonic acids and tested for antiviral and cytostatic activity. Despite the fact that no biological activity was found so far, the outcome of this work can serve as a useful tool in synthesis of novel groups of acyclic nucleoside phosphonates (ANPs).

The McKenna reaction is a well-known and popular method for the efficient and mild synthesis of organophosphorus acids. Bromotrimethylsilane (BTMS) is the main reagent in this reaction, which transforms dialkyl phosphonate esters into bis(trimethylsilyl)esters, which are then easily converted into the target acids. However, the versatile character of the McKenna reaction is not always used to its full extent, due to formation of side products. Herein, demonstrated by using model examples we have not only analyzed the typical side processes accompanying the McKenna reaction, but also uncovered new ones. Further, we discovered that some commonly recommended precautions did not always circumvent the side reactions. The proposed results and recommendations may facilitate the synthesis of phosphonic acids.

The drug, N,N bis (ethylene)-P (1-adamantyl) phosphonic diamide inhibits focus formation of Rous Sarcoma Virus in tissue culture. Transformation of chick cells was inhibited when the drug was added to chick cells prior to infection. The drug did not inhibit the transformation of Normal Rat Kidney Cells infected with RSV, when the cells were grown at non-permissive temperatures and shifted to permissive temperatures upon addition of the drug. Nor did the drug revert cells transformed at permissive temperatures. These studies indicated that the inhibition of RSV is in the early stage of viral growth, possible penetration or uncoating.

Lo sviluppo di nuovi nanosistemi ibridi organico-inorganici è un campo di ricerca all'avanguardia specifico per le applicazioni biomediche ad alto potenziale. In particolare, l'interazione tra i ligandi organici e le nanoparticelle inorganiche deve essere studiata e adattata in modo specifico al fine di ottenere stabilità e conferire proprietà specifiche ai nano-assiemi. Gli ZrNP sono sottoposti a approfonditi studi e funzionalizzazione per modificare le proprietà superficiali di questi materiali. La chimica superficiale della zirconia non è paragonabile a quella della silice, in particolare a causa della ridotta stabilità chimica del legame silanico da Zr – O – Si – R rispetto a Si – O – Si – R. Vale la pena notare che l'uso di derivati ​​del silano implica una reazione di condensazione con rilascio spesso di alcool o alogenuri come da prodotti. È noto che la zirconia, grazie alla sua struttura superficiale, può interagire efficacemente con ligandi a base di fosfato e fosfonato, come evidenziato anche dall'applicazione della zirconia per rimuovere i fosfati dall'acqua. Abbiamo considerato la reazione dell'estere vinilidenebisfosfonato con nucleofili attraverso Michael o etero-Michael come una reazione versatile che consente la preparazione da un comune scaffold di una vasta gamma di possibili prodotti BP a partire dal dietilfosfito attraverso la formazione di estere metilenbisfosfonato. Nel presente contributo introduciamo un approccio versatile per la modifica delle proprietà superficiali degli ZrNP e, in una certa misura, anche di altri NP di ossido di metallo, basato sull'impiego di una famiglia di BP come specie derivate. La funzionalizzazione è stata ottenuta miscelando semplicemente in soluzione acquosa la zirconia con i BP desiderati in condizioni tampone portando ad una vasta gamma di NP modificate in superficie con maggiore stabilità colloidale a causa della presenza di cariche negative sulla superficie su una vasta gamma di pH, come dimostrato da misurazioni ζ-potenziali. Le nanoparticelle modificate sono state caratterizzate da IR, TGA, XPS per studiare la densità dell'innesto e il carico dell'acido bifosfonico, TEM e SEM per studiare le dimensioni e le morfologie delle nanoparticelle e NMR a stato solido 31P e 1H per studiare il motivo di coordinazione del unità di fosfonati sulla superficie. Tutte queste tecniche analitiche hanno dimostrato la forte affinità della porzione bifosfonica per i centri metallici Zr (IV). L'acido bifosfonico ha mostrato anche un legame efficace con altre nanoparticelle di ossido di metallo come Bi2O3, mentre l'interazione con le nanoparticelle di SiO2 era troppo debole a causa del carattere non metallico dei centri Si. La funzionalizzazione delle nanoparticelle di ossido di metallo con acidi bifosfonici rappresenta un approccio covalente semplice per la derivatizzazione che è complementare ai tipici reagenti tris-alcossi-silano o tricloro-silano ampiamente impiegati per la funzionalizzazione di silice e nanoparticelle di ossido di metallo
TThe development of new hybrid organic-inorganic nanosystems is a cutting-edge field of research specifically for high potential biomedical applications. Specifically, the interaction between the organic ligands and the inorganic nanoparticles need to be specifically investigated and tailored in order to achieve stability and to impart specific properties to the nano-assemblies. ZrNPs are subjected to extensive study and functionalization to modify the surface properties of these materials. The surface chemistry on zirconia is not comparable to that of silica in particular due to the decreased chemical stability of the silane bond from Zr–O–Si–R with respect to Si–O–Si–R. It is worth to notice that the use of silane derivatives implies a condensation reaction with often release of alcohol or halides as by products. It is well known that zirconia, thanks to its surface structure, can efficiently interact with phosphate and phosphonate-based ligands, as evidenced also by the application of zirconia to remove phosphates from water. We considered the reaction of vinylidenebisphosphonate ester with nucleophiles through Michael or hetero-Michael as a versatile reaction enabling the preparation from a common scaffold of a wide range of possible BPs products starting from diethyl phosphite via formation of methylenebisphosphonate ester. In the present contribution we introduce a versatile approach for the modification of the surface properties of ZrNPs and to some extent also other metal oxide NPs, based on the employment of a family of BPs as derivatizing species. The functionalization was obtained by simple mixing in aqueous solution the zirconia with the desired BPs under buffered conditions leading to a wide range of surface modified NPs with enhanced colloidal stability due to the presence of negative charges on the surface over a wide range of pH, as demonstrated by ζ-potential measurements. The modified nanoparticles were characterized by IR, TGA, XPS to investigate the grafting density and the loading of the bisphosphonic acid, TEM and SEM to investigate the size and morphologies of the nanoparticles and 31P and 1H Solid State NMR to investigate the coordination motif of the phosphonate units on the surface. All these analytical techniques demonstrated the strong affinity of the bisphosphonic moiety for the Zr(IV) metal centers. The bisphosphonic acid showed also efficient binding to other metal oxide nanoparticles such as Bi2O3, while interaction with SiO2 nanoparticles was too weak due to the non-metallic character of the Si centers. The functionalization of metal oxide nanoparticles with bisphosphonic acids represents a straightforward covalent approach for derivatization that is complementary to the typical tris-alkoxy-silane or trichloro-silane reagents largely employed for the functionalization of silica and metal oxide nanoparticles.

De nos jours, l'industrie minière a connu une activité intense dans le domaine du développement de réactifs et additifs pour le traitement d'une grande variété de minerais. En outre, les recherches actuelles montrent un intérêt croissant pour les additifs de type collecteurs, dépresseurs ainsi que les agents chélatants, au regard de leur performance et leur efficacité au niveau industriel, et plus particulièrement dans l'industrie des phosphates.L'objectif ultime de ce travail de thèse est de développer de nouveaux réactifs et additifs « fait-maison » afin de soutenir et d'accompagner les développements futurs de l'industrie des phosphates au Maroc, et d'ouvrir ainsi de nouvelles perspectives. En conséquence, nos travaux de recherche sont concentrés sur la synthèse et la validation des performances de réactifs et additifs à l'échelle laboratoire, pilote et industrielle. Dans ce contexte, des agents, appartenant à des classes chimiques différentes, ont été conçus pour l'enrichissement des phosphates pauvres en P2O5 et pour l'élimination de certains métaux lourds. En effet, avec l'augmentation de la population mondiale, la demande croissante en engrais phosphatés dépourvus de métaux lourds, il devient urgent de faire un focus sur l'exploitation des phosphates à faible teneur en P2O5 et sur l'élimination des métaux lourds. Dans ce cadre, nous avons développé et évaluer différents agents organophosphorés, faits maison, lors des procédés de flottation inverse et de précipitation. Ces agents chimiques se sont avérés très efficaces et ont livrés des rendements élevés. Au cours de ces travaux de thèse, nous nous sommes également intéressés à la conception, la synthèse et l'évaluation de nouveaux acides bis-phosphoniques et de dihydropyrimidines dans le but de valoriser et diversifier le portefeuille de produit à base de P, en s'inscrivant dans le cadre d'une chimie verte et durable
Nowadays, the mining industry has seen intense activity in the development of reagents and additives for processing a wide variety of minerals, with a special focus on collectors, depressants, as well as chelating agents. Indeed, these agents demonstrated high performances at industrial level, and more particularly in the phosphate industry.The ultimate goal of this thesis work is to develop new “Home Made” reagents and additives in order to support ongoing developments in the phosphate industry in Morocco and to open new perspectives. Accordingly, our research work is focused on the synthesis and performance evaluation of reagents and additives at laboratory, pilot and industrial scales. In this context, agents, belonging to different chemical classes, have been designed for P2O5 low-grade phosphate beneficiation as well as for heavy metals removal. Indeed, with the increase in the world population and the growing demand for free-heavy metals phosphate fertilizers, it is of utmost importance to focus on the exploitation of P2O5 low-grade phosphates and the elimination of heavy metals. In this context, we developed and evaluated various home-made organophosphorus agents during reverse flotation and precipitation processes. These chemicals have proven to be very effective and have produced high yields. Furthermore, during this thesis work, we were also interested in the design, synthesis and evaluation of new bis-phosphonic acids and dihydropyrimidines, with the aim of enhancing and diversifying the portfolio of P-based products, within the framework of green and sustainable chemistry

In this work, binary solutions of cobalt and nickel in aqueous ammonium sulfate solutions were extracted using a simple shake-out technique with a mixed organic phase consisting of the extractant bis-(2-ethylhexyl)phosphonic acid (PC-88A), the modifier tributyl phosphate, and the diluent Esso Varsol DX3641. It was found that the optimum pH for the separation of cobalt and nickel was 5.0, and that the separation of the ions was a complex function of the porportion of cobalt and nickel in the equilibrium phases. The maximum metal loading of the organic phase, based on the population of dimer extractant complexes was approximately 73%. Two methods, used to describe the equilibrium extraction of two or more metal ions were compared namely, the Delta Y method and the Pseudo-Gamma approach. Each of these methods account for the non-ideal interactions between mixture components. Barclay's Pseudo-Gamma relationship was found to be simpler, and correlated the data very well. (Abstract shortened by UMI.)

碩士
國立臺北科技大學
化學工程研究所
101
In this thesis, a bis-phosphonate acid ligand 1,4-bis(methylene phosphonic acid) 2,3,5,6-tetramethylbenzene (H4bmpb) was reacted with transition-metal ions (MnII, CoII), and alkaline earth ions (BaII), at different temperatures and at different pH values, resulting in the formation of five coordination polymers 1-5. When the H4bmpb ligand was reacted with transition-metal ions (MnII, CoII), three coordination polymers were produced. Compounds 1 and 2 were prepared under different reaction conditions at different pH values. Compounds 1 and 2 were characterized by single-crystal X-ray diffraction analyses. The compounds are isostructures and adopt a 1D chain topology. Compound 3 was obtained as a co-crystal. The thermal stability and physical properties of the complexes were also examined. Compounds 4 and 5 were produced by the reaction of H4bmpb with a transition-metal ion (CoII) in the presence of 4,4''-bipyridine or 2,2''-bipyridine. Compound 4 is a 2D coordination polymer. The 2D layers are further stacked into a 3D MOF. However, when the temperature was increased to 60 °C, compound 5 was produced. This compound is a 1D chain and the chains are further linked into a 2D sheet. The structures, thermal stabilities and physical properties of products 1-5 are discussed in this thesis.

Substitutionally inert ruthenium complexes bearing benzimidazole derivatives have unique electrochemical and photochemical properties. In particular, proton coupled electron transfer (PCET) in ruthenium–benzimidazole complexes leads to rich redox chemistry, which allows e.g. the tuning of redox potentials or switching by deprotonation. Using the background knowledge from acquired from their solution-state chemistry, Ru complexes immobilized on electrode surfaces have been developed and these offer new research directions toward functional molecular devices. The integration of surface-immobilized redox-active Ru complexes with multilayer assemblies via the layer-by-layer (LbL) metal coordination method on ITO electrodes provides new types of functionality. To control the molecular orientation of the complexes on the ITO surface, free-standing tetrapodal phosphonic acid anchor groups were incorporated into tridentate 2,6-bis(benzimidazole-2-yl)pyridine or benzene ligands. The use of the LbL layer growth method also enables “coordination programming” to fabricate multilayered films, as a variety of Ru complexes with different redox potentials and pKa values are available for incorporation into homo- and heterolayer films. Based on this strategy, many functional devices, such as scalable redox capacitors for energy storage, photo-responsive memory devices, proton rocking-chair-type redox capacitors, and protonic memristor devices have been successfully fabricated. Further applications of anchored Ru complexes in photoredox catalysis and dye-sensitized solar cells may be possible. Therefore, surface-confined Ru complexes exhibit great potential to contribute to the development of advanced functional molecular devices.