Diphosphonic Acid Research Articles

Synthesis, crystal structure and proton conductivity of one Cu(II) coordination complex based on 2,2′-bipyridine-4,4′-diphosphonic acid

One proton-conductive Cu(II) coordination complex [Cu(H3L)Cl]n, in which H4L = 2,2′-bipyridine-4,4′-diphosphonic acid, was synthesized under hydrothermal condition. The product was structurally characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray diffraction analyses. The result of single-crystal X-ray diffraction analyses revealed that along c direction Cu2+ and Cl− atoms are joined together to be one infinite zigzag chain [CuCl]∞+. In b direction, adjacent [CuCl]∞+ chains are linked by [H3L]- ligands to be 2D layer. Along a direction, via hydrogen bonds of exposed phosphonic groups, 2D layers are stacked to be three-dimensional supramolecular network. This complex exhibits good proton conductivities 1.97 × 10−3–4.32 × 10−3 S cm−1 at 100 °C in the relative humidity range 35–98%. Moreover, at room temperature, the PXRD and TG analyses were employed to characterize the complex.

Inhibition of Phytophthora cinnamomi mycelial growth with stabilised hydrogen peroxide

The efficacy of hydrogen peroxide (H2O2) was evaluated for the inhibition of mycelial growth of Phytophthora cinnamomi in vitro. Phytophthora cinnamomi infects many crops globally causing root, collar and crown rot, resulting in significant economic losses for producers. Two 30% (w/v) H2O2 products, each stabilised with a different concentration of 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP) (3% versus 0.003% w/v) were compared to determine the most efficacious H2O2 concentration as well as potential interactive effects of the stabilising compound. Inhibition of P. cinnamomi growth was evaluated by amending potato dextrose agar media (PDA) with a range of concentrations of the test solutions. The biocidal activity of H2O2 was enhanced by a higher concentration of HEDP. Concentrations from 6.25 mL/L of the H2O2 product with 3% HEDP provided 100% inhibition of mycelial growth in vitro. Neither the product with 0.003% HEDP, nor HEDP stabiliser without H2O2, achieved comparable inhibition. Our results highlight an opportunity to expand the use of stabilised H2O2 products developed for cleaning of drip irrigation emitters to include the control of Phytophthora spp. and potentially other waterborne plant pathogens.

Influences of Ferric Ions and Fe as a Minor Element in the Lattice on the Floatability of Cassiterite.

In this study, synthetic pure cassiterite and cassiterite doped with two different Fe contents were successfully recrystallized by means of sintering. Their crystal structure and chemical compositions were characterized by X-ray powder diffraction (XRD) as well as scanning electron microscopy (SEM) combined with energy-dispersive X-ray (EDX) analysis. Their floatability was studied by microflotation with a diphosphonic acid surfactant named Lauraphos301 as a collector. Unlike the addition of ferric ions in solution, which strongly depressed the floatability of all of the cassiterite samples, a much higher flotation efficiency of the Fe-doped cassiterite samples was found especially at lower collector concentrations. The cassiterite floatability is proportional to the Fe content in cassiterite at a broad range of pH, and the recovery has the following order: cassiterite with 1417 ppm Fe > cassiterite with 1165 ppm Fe > pure cassiterite. The electrokinetic behavior of the cassiterite samples with and without the collector was studied by electrophoretic measurements and revealed that the chemical interaction dominated the adsorption. With the help of the particle shape analysis, a more angular shape was found for the Fe-doped cassiterite samples. Moreover, without the influence of particle shape, much abundant adsorption of Lauraphos301 was found on the Fe-doped cassiterite samples by AFM topography imaging. The minor amount of Fe in the cassiterite lattice and a more angular shape of the Fe-doped cassiterite samples were believed to enhance floatability collectively. The study reveals that the influence of the chemical composition of the minerals on flotation was almost inextricably bound up with particle morphology and emphasizes the importance of considering both factors and investigating them individually for the flotation study.

Artificial phosphate solid electrolyte interphase enables stable MnO2 cathode for zinc ion batteries

Rechargeable aqueous zinc-ion batteries based on manganese-based cathode materials are promising energy storage devices, but the low conductivity and dissolution issues of manganese-based cathode materials lead to instability. In order to address these issues, this work proposes an in situ reaction between hydroxyethylene-1,1,-diphosphonic acid and manganese dioxide to create a phosphorylated manganese dioxide (PMO) cathode on which a phosphate solid electrolyte interphase was built. This artificial organic electrolyte interface improves the stability of the cathode during cycling, allowing it to deliver capacities of 250 mAh g−1 and 105 mAh g−1 at current densities of 0.1 A g−1 and 1.0 A g−1, respectively. The intrinsic mechanism of this phosphate retards the side reactions caused by water attack. This strategy provides a general design strategy for manganese-based cathode materials for aqueous zinc ion batteries.

Molecular Orientation of -PO3H2 and -COOH Functionalized Dyes on TiO2, Al2O3, ZrO2, and ITO: A Comparative Study.

Modification of transparent metal oxide (MOx) surfaces with organic monolayers is widely employed to tailor the properties of interfaces in organic electronic devices, and MOx substrates modified with light-absorbing chromophores are a key component of dye-sensitized solar cells (DSSCs). The effects of an organic modifier on the performance of a MOx-based device are frequently assessed by performing experiments on model monolayer|MOx interfaces, where an "inert" MOx (e.g., Al2O3) is used as a control for an "active" MOx (e.g., TiO2). An underlying assumption in these studies is that the structure of the MOx-monolayer complex is similar between different metal oxides. The validity of this assumption was examined in the present study. Using UV-Vis attenuated total reflection spectroscopy, we measured the mean dipole tilt angle of 4,4'-(anthracene-9,10-diyl)bis(4,1-phenylene)diphosphonic acid (A1P) adsorbed on indium tin oxide (ITO), TiO2, ZrO2, and Al2O3. When the surface roughness of the MOx substrate and the surface coverage (𝛤) of the A1P film were constant, the molecular orientation of A1P was the same on these substrates. The study was extended to 4,4'-(anthracene-9,10-diyl)bis(4,1-phenylene)dicarboxylic acid (A1C) adsorbed on the same group of MOx substrates. The mean tilt angle of A1C and A1P films on ITO was the same, which is likely due the intermolecular interactions resulting from the high and approximately equal 𝛤 of both films. Comparing A1C films at the same 𝛤 on TiO2 and Al2O3 having the same surface roughness, there was no difference in the mean tilt angle. MD simulations of A1C and A1P on TiO2 produced nearly identical tilt angle distributions, which supports the experimental findings. This study provides first experimental support for the assumption that the structure of the MOx-modifer film is the same on an "active" substrate vs. a "inert" control substrate.

Selective Flotation Behavior of Dolomite from Fluorapatite Using Hydroxy Ethylene Diphosphonic Acid as High-Efficiency Depressant

In the reverse flotation of fluorapatite and dolomite, high-efficiency depressors of fluorapatite have received considerable attention. In this paper, the depression mechanism of hydroxy ethylene diphosphonic acid (HEDP) was studied for the first time as a novel fluorapatite depressant on the surface of fluorapatite. The effect of HEDP on the flotation behavior of the two minerals was studied by single and mixed minerals in flotation tests. HEDP exhibited an excellent depression effect on fluorapatite flotation, whereas its adsorption on dolomite surface was minimal. Fluorapatite and dolomite were effectively separated by applying sodium oleate as a collector and HEDP as a depressant at pH 6.0. The depression mechanism of HEDP on fluorapatite was further analyzed via contact angle measurement, zeta potential and X-ray photoelectron spectroscopic (XPS) analysis. We found that HEDP seriously hindered the adsorption of sodium oleate (NaOL) on the fluorapatite surface and had a minimal effect on the dolomite surface. XPS analysis results indicate that the strong adsorption of HEDP on the fluorapatite surface can be attributed to the strong chelation between the electron-rich groups of HEDP and Ca ions on the fluorapatite surface. Therefore, HEDP is used as a selective depressant of fluorapatite in the fluorapatite–dolomite flotation–separation process.

Simultaneous adsorption removal of organic and inorganic phosphorus from discharged circulating cooling water on biochar derived from agricultural waste

A high level of organic and inorganic phosphorus exists in discharged circulating cooling water (DCCW), therefore, the efficient removal of phosphorus from DCCW is necessary. Herein, the adsorption performance and mechanism of hydroxyethylidene diphosphonic acid (HEDP) and phosphate from DCCW on pyrolysis biochar derived from agricultural waste (wheat and corn straw wastes, and peanut shell powder) were systematically investigated. Among them, biochar prepared from wheat straw and modified with MgCl2 and CeCl3 (molar ratio 3:1), i.e., WS-3Mg/Ce, showed optimal phosphorus removal from DCCW. The pseudo-second-order and Freundlich model well described the adsorption of HEDP, PO43−, and total phosphorus (TP) on WS-3Mg/Ce. Further, negative Gibbs free energy (ΔG) indicated that WS-3Mg/Ce adsorbed HEDP and phosphate through physical adsorption and chemical reactions, with the chemical reaction being dominant. Scanning electron microscopy-energy dispersive X-ray spectroscopy and X-ray diffraction results revealed that CePO4 and Mg3(PO4)2 appeared on WS-3Mg/Ce after adsorption, and the diffraction bands of metal oxides or hydroxides decreased. Fourier transform infrared and X-ray photoelectron spectroscopy results showed that O–H, M-O, M-O-P, and O–P on the surface of WS-3Mg/Ce participate in the reaction. This suggests that the adsorption of HEDP and phosphate on WS-3Mg/Ce mainly involves metal binding via Ce and Mg, and chemical complex via OH−. This study provides a promising approach for removing different forms of phosphorus simultaneously from DCCW via biochar and contributes to the resource recovery of agricultural and forestry waste. Future work is needed for the optimization of the biochar to promote the adsorption capacity and renewability in treating real DCCW.

Phosphonate removal from membrane concentrate by electro-coagulation

In this study, the efficiency of electrocoagulation (EC) with iron electrodes was applied to remove two phosphonates, 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP) and nitrilotris(methylene) triphosphonic acid (NTMP) from concentrates. This work provides a detailed description of the experimental procedure and results on phosphonate removal and recovery from different electrolytes, including synthetic and real reverse osmosis (RO) membrane concentrates. This research showed high selectivity of EC, removing 100% and 80% of the NTMP and the HEDP respectively, confirming no competition with sulfates, nitrates, or silica. When experimenting with other electrolytes, calcium showed to be critical in enhancing the flocculation process, while calcium carbonate precipitation contributed to capturing the phosphonates from the concentrate. The produced iron oxide (sludge) was confirmed as goethite and akaganéite, and finally transformed into hematite, indicating the oxidation from Fe2+ to Fe3+ during the EC process. After the iron precipitate collection, an alkaline wash of the sludge was enough to recover 100% of the initial phosphorus from the NTMP phosphonate. However, further research is needed to optimize the recovery procedure and to improve the results with the HEDP. 70 and 140 A·m−2 current densities were optimal to bring HEDP and NTMP concentrations down to 32 μM (1 mg·L−1) in only 30 and 10 min respectively. In these conditions, the operational costs, 1.10 and 0.03 €·m−3 of treated concentrate, were estimated for HEDP and NTMP respectively. Even when EC has been widely studied for phosphate removal, this technique has been barely applied to treat concentrates containing phosphonate-based antiscalants. EC opens new possibilities for phosphonates and phosphorus to be removed and recovered respectively from membrane and other concentrates.

An Enhanced Electrokinetic/Waste Fe(OH)3 Permeable Reactive Barrier System for Soil Remediation in Sulfide Mine Areas

Traditional electrokinetic (EK) technology can remove contaminants from soil, but the efficiency is generally low. This study reports on the combination of enhanced EK and a waste ferric hydroxide (Fe(OH)3) permeable reactive barrier (PRB) for the remediation of soil in sulfide mine areas. Hydroxyethylene diphosphonic acid (HEDP) and FeCl3 were used as a compound chelating agent. The experimental results showed that EK combined with PRB technology (95.32% Cd removal) was more effective than single EK in removing cadmium (Cd) from the contaminated soil, because of the compound chelating agent and PRB filled with sustainable Fe(OH)3 adsorbent. Additionally, the application of PRB in combination with HEDP was able to increase the sulfate removal rate to 96.19%. The accumulated energy consumption of these two systems was 182.4 and 356 kWh/m3, respectively, after EK remediation using PRB.

Efficient water reduction by ruthenium-picolinate dye-sensitized photocatalyst under red light illumination

To utilize a wider region of the solar spectrum for solar-fuel production, we newly synthesized a heteroleptic Ru(II)-picolinate complex, [Ru(H4dpbpy)2(pic)]+ (Rupic; H4dpbpy = H4dpbpy = 2,2′-bipyridine-4,4′-diphosphonic acid, Hpic = picolinic acid) as a red light-absorbing molecular photosensitizer. Rupic exhibited metal-to-ligand charge-transfer (MLCT) absorption and emission (λabs and λem = 491 and 711 nm, respectively) over a longer wavelength region than that observed with the bipyridine derivative [Ru(H4dpbpy)2(bpy)]2+ (Rubpy, bpy = 2,2′-bipyridine). The Ru(III)/Ru(II) redox potential of Rupic (Eox = +1.07 vs NHE) was approximately 0.27 V more negative than that of Rubpy, owing to the weaker ligand field strength of pic than that of bpy. Moreover, as expected, owing to the red-light absorption ability of Rupic, the photocatalytic H2 evolution reaction activity of the Rupic-sensitized Pt-TiO2 nanoparticles (apparent quantum yield, AQY ∼ 3 %) under red light illumination (λ = 625 ± 35 nm) was significantly higher than that of its Rubpy-sensitized analog (AQY ∼ 0.5 %). These results indicate the superior photosensitizing performance of the Ru(II)-picolinate complex for H2 production under sunlight illumination.

Synthesis and Structure Evolution in Metal Carbazole Diphosphonates Followed by Electron Diffraction.

To access porous metal phosphonates, a new V-shaped, rigid, and sterically demanding diphosphonic acid, namely 3,6-diphosphono-9H-carbazole (H4L), was designed and employed in a high-throughput investigation. Screening of different metal salts and subsequent optimization studies resulted in the isolation of two porous metal phosphonates [Cu2(H2O)2(L)]·2H2O (CAU-37) and [Zn6.75(H2O)1.5(HL)2.5(L)1.5]·8H2O (CAU-57). Structure determination was accomplished by electron diffraction and the dehydration behavior of CAU-37 was followed in situ. A rare case of intralayer water de-/adsorption in CAU-37 was found which leads to a cell volume change of 11.9%. Rod-shaped inorganic building units (IBUs) are connected to layers and structural flexibility is due to "accordion-like" structural changes within the layers. In contrast, in CAU-57 a layered IBU is found, which usually results in the formation of dense structures. Due to the shape and rigidity of the linker, the interconnection of the IBUs results in the formation of pores. Water sorption measurements in combination with powder X-ray diffraction data confirmed the reversibility under structural retention.

Optimization of scale inhibitors nitrilotriacetic acid and 1-hydroxyethylidene-1, 1-diphosphonic acid, effect of magnesium ions and temperature on calcium carbonate scale

Optimization of scale inhibitors nitrilotriacetic acid and 1-hydroxyethylidene-1, 1-diphosphonic acid, effect of magnesium ions and temperature on calcium carbonate scale

Adsorption properties and mechanism research of phosphorus with different molecular structures from aqueous solutions by La-modified biochar.

In order to explore the adsorption characteristics of phosphorus from molecules with different molecular structures and varying number of phosphate groups on metal-modified biochar, walnut shell biochar was modified with LaCl3 to prepare lanthanum-loaded biochar (BC-La). Adsorption of four polar components, namely phytic acid (IHP), adenosine-5'-disodium triphosphate (5-ATP), hydroxyethylidene diphosphonic acid (HEDP), and sodium pyrophosphate (PP), was studied. The adsorption properties and mechanism of phosphorus sorption by BC-La were analyzed by SEM-EDS and FTIR for the different structures. The results showed that the maximum adsorption capacity of BC-La for IHP, 5-ATP, HEDP, and PP was 85.85, 9.04, 15.80, and 14.45mg/g, respectively. The adsorption capacity was positively correlated with the polarity of organic phosphorus. The adsorption behavior conformed to the quasi second-order kinetic fitting equation, and the increase of temperature was conducive to the removal of all four phosphorus pollutants. BC-La adsorbs IHP and HEDP mainly through electrostatic attraction. The adsorption of 5-ATP and PP is dominated by complexation. The La-modified biochar has broad prospects in water remediation, which can provide a theoretical basis for removal of different forms of phosphorus pollutants and prevention and control of water eutrophication.

DEVELOPMENT AND ESTIMATION OF HUMAN DOSIMETRY OF A NEW 47SC-RISEDRONATE FOR RADIOPHARMACEUTICAL APPLICATION.

Bisphosphonate risedronate (2-(3-pyridinyl)-1-hydroxyethane diphosphonic acid) was radiolabeled with scandium-47 (47Sc) as potential therapeutic radiopharmaceutical for skeletal metastases. Its time-dependent biodistribution in mice was measured and its human dosimetry was derived. The labelling process was performed at 95°C for 30min. The stability of the radio-conjugate was tested in human serum at 37°C and its biodistribution was studied in balb/c mice. The radiochemical yield of ≥90% was obtained corresponding to a specific activity of 277MBq/mg. The radio-conjugate showed good stability in human serum up to 48h. A high bone uptake by 48h post-injection was achieved, which suggests that 47Sc-risedronate may be therapeutically beneficial for the palliation of painful bone metastasis. The estimated absorbed dose coefficient and the time-integrated activity coefficient (ã (rs, TD)) in the bone were 1.35mGy/MBq and 31.04 (Bq-h/Bq), respectively. The absorbed doses to non-osseous normal organs were much lower than that to the bone.

Electrochemical deposition of copper on zinc and its alloys

A new electrolyte composition and deposition conditions of quality (light, densely packed, homogeneous) copper coatings on zinc and its alloys were found. It was established that the electrochemical deposition of copper is possible from an alkaline solution containing propylene glycol. It was shown that the adding of hydroxyethylidene diphosphonic acid in the solution stabilises the electrolyte during operation and storage. The addition of morpholine provided deposition of quality copper coatings on zinc and its alloys in a wide range of current densities.

Structure solution using 3DED of beam- and vacuum-sensitive carbazole-based di-phosphonic acid metal–organic frameworks

Structure solution using 3DED of beam- and vacuum-sensitive carbazole-based di-phosphonic acid metal–organic frameworks

The Impact of Laser-Activated and Conventional Irrigation Techniques on Sealer Penetration into Dentinal Tubules.

Objective: The present study was aimed at comparing the efficacy of 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP) and ethylenediaminetetraacetic acid (EDTA) by using various final irrigation techniques on penetration of sealer. Background: Traditional irrigation of root canals with a syringe limits the ability of sealer penetration. Various irrigants and activation techniques, including sonic and ultrasonic devices and various kinds of lasers, have been introduced to improve penetration of sealers into dentinal tubules. Methods: One hundred mandibular premolars were selected. Final irrigation was performed with HEDP or EDTA by conventional syringe irrigation (CI), EndoActivator (EA), passive ultrasonic irrigation (PUI), photon-induced photoacoustic streaming (PIPS), and shock wave-enhanced emission photoacoustic streaming (SWEEPS) methods (n = 10). After obturation of root canals with the EndoSequence BC Sealer, samples were evaluated using a confocal laser scanning microscope (CLSM), which enabled measurement of the maximum depth, percentage, and penetration area. Tests performed for analysis included the Kruskal-Wallis H and Mann-Whitney U tests. Results: In the EA method, the penetration percentage achieved using HEDP was significantly higher than EDTA at both sections (p < 0.05). Irrespective of the final irrigation solution employed, the PUI, PIPS, and SWEEPS techniques exhibited greater tubule penetration values compared with the CI and EA techniques (p < 0.05). Conclusions: HEDP and EDTA showed similar effects on the amount of penetrated sealer into the dentinal tubules, and the PUI, PIPS and SWEEPS methods provided enhanced EndoSequence BC Sealer penetration compared with the CI and EA methods. This study was approved by the Near East University institutional review board (#2020/86-1225).

Carbon dots with tailor-made chelating ligands for specific metal ions recognition: Target synthesis and prediction of metal ions selectivity

Carbon dots (CDs) have been widely applied in metal ion recognition and detection, which makes them promising in the fields of environmental monitoring and biomedical science. However, CDs usually contain multiple functional groups that have different affinities for metal ions, so the relationship between CDs and recognized metal ions is ambiguous, which limits the prediction of recognized metal ions. Herein, CDs with different chelating ligands were target synthesized via free radical polymerization in combination of hydrothermal carbonization technology, the precursors directional converted into CDs. The tailor-made CDs with ethylenediamine tetraacetic acid (EDTA, EfCDs) and hydroxyethylidene diphosphonic acid (HEDP, HfCDs) chelating ligands were synthesized with high synthetic yields of 86.7% and 72.5%, respectively. The coordination constant (K) and the number of chelation site (n) of EfCDs for Fe3+ were (3.92 ± 0.03) × 104 M−1 and 3.62 ± 0.18, while the values of K and n of HfCDs for Cu2+ were (5.95 ± 0.04) × 105 M−1 and 1. EfCDs and HfCDs can serve as fluorescence probes for specific recognition of Fe3+ and Cu2+, respectively. Based on the metal-chelating affinity of EDTA and HEDP for Fe3+ and Cu2+ (lgKEDTA-Fe = 25.1, lgKHEDP-Cu = 12.5), EfCDs and HfCDs were predicted to specifically recognize Fe3+ and Cu2+. We established the exponential type functions between fluorescence quenching degree (1-F/F0) and coordination constant (lgK) of EDTA or HEDP to facilitate the prediction of specific recognition of metal ions. This study proposes a new strategy for heavy metal ions specific recognition using CDs with tailor-made chelating ligands.

Hybrid porous titania phosphonate networks with different bridging functionalities: Synthesis, characterization, and evaluation as efficient solvent separation materials

Hybrid titania phosphonate materials can demonstrate a high added value as tailored sorption materials. They combine high chemical stability with great structural versatility, given the wide diversity of functional groups that can be incorporated. Hereto, a fundamental understanding of the synthesis strategies influencing the material performance is required. Therefore three porous TiO2 phosphonate hybrid structures with different functional groups (octyl, propyl, and phenyl) were evaluated in a solid-phase extraction application aimed towards solvent separation. The synthesis was performed by mixing bridged diphosphonic acids (DPAs) with Ti(OBu)4 in a water-ethanol mixture at 30 °C, followed by a hydrothermal post-treatment at 120 °C. The materials were characterized by ICP-AES, 31P solid-state CP/MAS NMR, Raman and FTIR spectroscopy, X-ray diffraction, N2-sorption, and transmission electron microscopy. It is shown that the diphosphonic acids are quantitatively incorporated in the hybrid structures, leading to nanosized particles with a complex but uniquely functionalized surface. A study of the pore structure as a function of the incorporated DPA amount showed materials with a maximum BET surface area of 379 m2/g. The alkyl functionalized hybrid titania phosphonates demonstrated excellent and tunable sorption behavior.

PH-responsive smart composite coating with active anticorrosion and efficient scale inhibition properties

In this work, porous polysulfone (PSF) microcapsules were prepared using the method of mixed solvent volatilization, these microcapsules were used as a carrier, 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP) was used as an active substance for scale and corrosion inhibition, and stearic acid (SA) was used as a coating to prepare a pH-responsive smart microcapsule slow-release filler. Then, the smart microcapsules were added to a polyurea resin to prepare a pH-responsive smart composite coating with anti-corrosion and scale inhibition properties. The results showed that SA/PSF/HEDP microcapsules have significant pH-triggering activity in an alkaline environment. The alkaline supersaturated CaCO3 solution test showed that the composite coating has excellent scale inhibition performance. This is attributed to the in the microcapsules being released to the coating surface, achieving the purpose of complexation and solubilization. Local electrochemical impedance spectroscopic (EIS) proved that the SP/SA/PSF/HEDP composite coating has good corrosion resistance. This is attributed to the release of corrosion inhibitors, which can form a dense protective film on the metal. The scale inhibition efficiency of the composite coating was as high as 78.57 %, and the impedance modulus value is increased by three orders of magnitude.