Diphenyl Phosphonic Acid Research Articles

Simple and environmentally friendly preparation strategy of zeolite supported iron diphenylphosphate for improving the fire safety of EP

The design of efficient epoxy resin (EP) flame retardants and the exploration of low toxicity and sustainable flame retardants strategies remain a great challenge. This work proposed a novel Zeolite@DPA-Fe flame retardant was prepared by a simple and environmentally friendly aqueous solution method using natural zeolite, iron chloride and diphenyl phosphonic acid as the main raw materials, which was used to improve the fire safety of EP. The results showed that Zeolite@DPA-Fe can endow EP with good flame retardant properties. After adding 5 wt% Zeolite@DPA-Fe, the LOI of EP composites was 32.2 %, reaching UL-94 V-0 grade. In addition, the catalytic charring of Zeolite@DPA-Fe promoted the graphitization of the char layer and significantly reduced the rate of heat release and smoke production during composite combustion. Hence, this study provides a promising strategy for the preparation of highly efficient and environmentally friendly flame retardant EP composites.

A novel and convenient zeolite modification strategy for enhancing the fire resistance of epoxy resin

The preparation process of new environmentally friendly flame retardants to endow epoxy resin (EP) with excellent flame retardancy and mechanical properties remains a challenging task. In this study, a novel Zeolite@DPA-Cu flame retardant was designed and prepared by a simple and environmentally friendly aqueous preparation process using zeolite, copper sulfate and diphenylphosphonic acid as main raw materials. As expected, Zeolite@DPA-Cu significantly improved the flame retardancy and mechanical properties of EP composites. The results showed that the LOI and UL-94 grade of the EP/5 wt% Zeolite@DPA-Cu composite reached 32.4 % and V-0 rating, respectively. The synergistic effect of the physical barrier, free radical capture and catalytic char formation of Zeolite@DPA-Cu significantly improved the flame retardancy of EP. In addition, due to the strong interfacial interaction between Zeolite@DPA-Cu and EP, the tensile strength and elongation at break of the EP were increased to 57.92 MPa and 4.7 %, respectively. Generally, this study proposed a modification strategy that takes into account both flame retardancy and mechanical properties, which is extremely important for the practical application of EP flame retardant materials.

Syntheses, structures and mechanisms of interactions with DNA of two new 20-core silver(I) complexes with different ligands

Two different silver(I) complexes with diphenylphosphonic acid as peripheral ligand were designed and synthesized by using different solvents. The complexes were characterized by X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (IR), elemental analysis (EA), thermogravimetric analysis (TG). Single crystal X-ray analysis established the final structure of both complexes. The interaction modes of the two clusters with DNA were investigated by fluorescence and electrochemical analysis. The theoretical result was justified with the help of theoretical data. The results established that the cluster with methanol solvent was more stable binding with the DNA and protein than the cluster with DMF molecule.

Synthesis of As(V)-Cr(III) Co-Imprinted Polymer and Its Adsorption Performance for Arsenate Species

A novel mixed As(V)-Cr(III) ions co-imprinted polymer (MICIP) was synthesized with two functional monomers, 1,12-dodecanediol-O,O’-diphenyl-phosphonic acid (DDDPA) and 4-vinylpyridine (4-VP), by W/O/W polymerization. Arsenate and Cr(III) ions were simultaneously chosen as templates while Cr(III) ions played a role of the synergetic ions to improve the imprinting of arsenate on the ion-imprinted polymer. The adsorption performance of the MICIP has been investigated by adsorption experiments. The results showed that the MICIP was efficient for the simultaneous removal of Cr(III) and arsenate ions when pH was 4 to 5. It was found that Cr(III) ions had a significant synergetic effect on the selective adsorption of arsenate onto the MICIP in a mixed As(V) and Cr(III) solution and the MICIP showed little adsorption ability on arsenate without Cr(III) ions in solutions. The adsorption isotherm of arsenate ions on the MICIP was well described by the Freundlich model (R2 > 0.99). The adsorption process obeyed the pseudo second-order kinetics and reached the equilibrium after 24 hours. The MICIP had high selectivity for arsenate anions in the presence of competitive ions with selectivity coefficients of 22.0 and 3.17 for k(As/Cd) and k(As/Ni), respectively.

Synthesis and adsorption performance of lead ion-imprinted micro-beads with combination of two functional monomers

A novel ion-imprinted polymer, lead ion-imprinted micro-beads with combination of two functional monomers, was synthesized using the W/O/W polymerization method. Two functional monomers, 1,12-dodecanediol-O,O'-diphenyl-phosphonic acid (DDDPA) and 4-vinylpyridine, were used to form a suitable construction with micro-pores fitting the template and recognition sites. The effects of adsorbent dosage, solution pH and the competitive ions on the adsorption and separation efficiency of lead ions were investigated. The lead ion-imprinted micro-beads were efficient for lead ions removal from aqueous solution in a broad pH range (4–9), when the adsorbent dosage was above 0.1 g/L. The adsorption process obeyed the pseudo second-order kinetics model and it only took half an hour to reach the equilibrium. The adsorption isotherm of lead ion was described by the Langmuir model ( R 2 >0.99) with a maximum adsorption capacity of 116.9 mg/g. In the presence of competitive ions Co 2+ and Cd 2+, the lead ion-imprinted micro-beads showed a high selectivity for lead ions. The selectivity coefficient of Pb 2+/Cd 2+ and Pb 2+/Co 2+ are 99.3 and 114.7, respectively.

Nature of the P [sbnd]O bond in diphenylphosphonic acid: experimental charge density and electron localization function analysis

Analysis of the electron density function and the ELF on the basis of the high resolution diffraction X-ray investigation of Ph2P(O)OH at 110 K have revealed that, in the vicinity of the oxygen atom of the P=O group, three lone pairs in an antiperiplanar orientation in respect to OH and Ph substituents are localised.

Metal-imprinted microsphere prepared by surface template polymerization and its application to chromatography

A metal ion-imprinted microsphere was prepared by surface molecular template polymerization. Trimethylolpropane trimethacrylate (TRIM), zinc ions, 1,12-dodecanediol-O, O′-diphenyl phosphonic acid (DDDPA) were used as a crosslinking agent, an imprint molecule, and a functional host molecule. The Zn(II)-imprinted microspheres, which are spherically well-defined particles, were prepared by using water-in-oil-in-water (W/O/W) multiple emulsions. The combination of TRIM and DDDPA serves to align the recognition sites resulting in better template sites produced on the polymer surface. We firstly conducted diagnostic zinc- and copper-ion adsorption tests with the Zn(II)-imprinted and unimprinted microspheres in order to make an assessment on the effectiveness of the molecular imprinting technique. Further, the metal-imprinted microspheres were applied to the column operation. The separation and recovery of metals were carried out by an adsorption column packed with the Zn(II)-imprinted microspheres. This performance was compared to that of commercial chelating resins that possess similar phosphoric functional groups. The Zn(II)-imprinted polymer shows an extremely high selectivity to the imprinted zinc ions compared to that of the commercial chelating resin. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 689–696, 2000

Metal ion imprinted microsphere prepared by surface molecular imprinting technique using water-in-oil-in-water emulsions

A novel metal ion imprinted polymer was prepared by the surface molecular imprinting technique. Trimethylolpropane trimethacrylate (TRIM), zinc ions, and 1,12-dodecanediol-O,O′-diphenyl phosphonic acid (DDDPA) were used as the matrix-forming monomer, imprint molecule, and functional monomer, respectively. We have prepared Zn(II)-imprinted microspheres utilizing water-in-oil-in-water emulsions, which are spherically well defined and uniform. TRIM comprises of three polymerizable groups that serve to align the recognition sites produced on the polymer surface with better template effect. We conducted diagnostic zinc adsorption tests by using the Zn(II)-imprinted and unimprinted polymers in order to make an assessment on the effectiveness of TRIM-based and divinylbenzene-based imprinted polymers. The template effect of the TRIM-based polymer was enhanced by the high rigidity of the polymer matrix compared to that of the imprinted polymer whose matrix is divinylbenzene. In addition, the adsorption equilibrium constant was evaluated on the basis of the Langmuir analysis for the adsorption data. The method to prepare metal-imprinted microspheres on the surface of polymers crosslinked by TRIM is easy, and the adsorbent produced can be readily used without subsequent grinding or sieving. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1223–1230, 1999

Spacer effect of novel bifunctional organophosphorus monomers in metal-imprinted polymers prepared by surface template polymerization

The interfacial activity and the molecular structure of functional monomers are critical factors that determine the success of synthesizing metal-imprinted polymers by surface template polymerization. From this point of view, first we prepared three distinct novel bifunctional organophosphorus monomers that are interspaced, in each case, by an alkyl spacer having a specific length. Each monomer carries two phosphonic acid groups and two aromatic groups in its molecular structures. Further, by using the synthesized bifunctional monomers, we prepared highly selective Zn(II)-imprinted polymers by the surface template polymerization initiated from a water-in-oil emulsion. To evaluate the template effect, we conducted diagnostic adsorption studies on Zn(II)-imprinted and unimprinted polymers with zinc ions. A high interfacial activity was found to be required for the functional monomers to create the predominant template effect. It became clear that Zn(II)-imprinted polymers having bifuctional monomers with 12-length alkyl chains (1,12-dodecanediol-O, O'-diphenyl phosphonic acid: DDDPA) yielded the best results. Moreover, analysis results of adsorption behavior supported a high-performance of the Zn(II)-imprinted polymers with DDDPA.

A NEW STRUCTURAL FORM OF TIN IN AN OXYGEN-CAPPED CLUSTER

Abstract Recently we have shown that oligomeric organotin oxycarboxylates based on the compositions [R'Sn(O)O2CR]6 and [(R'Sn(O)O2CR)2R'Sn(O2CR)3]2 have “drum” 1-3 and “ladder”2,3 structures, respectively. Reaction of n-butylstannoic acid with diphenylphosphonic acid instead of a carboxylic acid results in the for- mation of an analogous drum composition, [n-BuSn(O)O2P(OPh)2]6.4 However, when diphenylphosphinic acid is reacted with n-butylstannoic acid under reflux in toluene, a new structural form of tin is obtained. This report concerns the synthesis and structural characterization of this novel substance.

Synthesis and characterization of platinum and palladium clusters with phosphide ligands

Clusters of composition [Pt(PPh 2)] n, n = 6−10, have been synthesized by reduction of a series of Pt II complexes [(PPh 3)Pt (OAc)G] m (G = (OAc) 2 · PdC 3H 5, m = 1; G = Cl, OAc, (OAC) 2Ag, m = 2) with H 2, HCOOH and Na-amalgam. A hydridophosphide Pd II complex [Pd 2(PPh 2)H x] n was obtained in an analogous manner by reduction of [(PPh 3)Pd(OAc) 2] 2 with HCOOH. Additionally a complex with diphenylphosphonic acid as a ligand [Pd(μ-O 2PPh 2)(C 6H 5)(PPh 3)] 2 was obtained and characterized with X-ray data. The formation of O 2PPh 2 anion under strictly anaerobic reductive conditions implies the transfer of an O atom from the carboxylic ligand to the P atom of the phosphorus-containing ligand. Cleavage of the CPh bond seems to be a common process for the reductive reactions of both Pd and Pt phosphine complexes. Phosphide clusters of compositions [Pt(PPh 2) n , and [Pd 2(PPh 2)H x] n were characterized with IR, SAXS, EXAFS and NMR data and molecular mass measurements.

Organoaluminum-phosphine chemistry. Synthesis and molecular structure of [Ph 2P(O) 2 · AlCl 2] 2 and [Ph 2P · Al(i-Bu) 2] 2

The crystalline complex [Ph 2P(O) 2 · AlCl 2] 2 (I) was prepared by reaction of the disproportionation product of ethylaluminum sesquichloride, EtAlCl 2, or by direct reaction of EtAlCl 2 with diphenylphosphonic acid, Ph 2P(O)OH, in a heptane/toluene mixture. I crystallizes in the monoclinic space group C2/ c with unit cell parameters a 11.201(9), b 15.059(6), c 17.665(5) Å, β 105.4°(2), V 2979.7 Å 3 and D calc 1.40 g cm −3 for Z = 4. Least-squares refinement based on 1656 observed reflections led to a final R factor of 0.047 ( R 2 = 0.062). I resides about a crystallographic center of symmetry. The core of the dimer consists of a planar eight-membered (Al-O-P-O) 2 ring. The mean Al-O bond distance is 1.73(1) Å while the independent Al-Cl bond distance is 2.085(2) Å. The organoaluminum crystalline product [Ph 2P · Al(i-Bu) 2] 2 (II) was prepared by reaction of diisobutylaluminum hydride with diphenylphosphine in heptane. II crystallizes in the orthorhombic space group Pbca with unit cell parameters a 12.809(2), b 15.207(2), c 20.574(3) Å, V 4008.5 Å 3, and D calc 1.08 g cm −3 for Z = 4. Least-squares refinement based on 2111 observed reflections converged at R = 0.036, R w = 0.049. The dimeric organoaluminium compound possesses crystallographic inversion symmetry and contains a planar four-membered Al 2P 2 ring. The mean Al-P bond distance is 2.476(1) Å. The Al-P-Al bond angle in the Al 2P 2 ring is 93.8(1)° while the P-Al-P bond angle is determined to be 86.2(1)°. The Al ··· Al and P ··· P contact distances are 3.615(1) Å and 3.381(1) Å, respectively.

A new structural form of tin in an oxygen-capped cluster

Abstract Recently we have shown that oligomeric organotin oxycarboxylates based on the compositions [R'Sn(O)O2CR]6 and [(R'Sn(O)O2CR)2R'Sn(O2CR)3]2 have “drum” 1-3 and “ladder”2,3 structures, respectively. Reaction of n-butylstannoic acid with diphenylphosphonic acid instead of a carboxylic acid results in the for- mation of an analogous drum composition, [n-BuSn(O)O2P(OPh)2]6.4 However, when diphenylphosphinic acid is reacted with n-butylstannoic acid under reflux in toluene, a new structural form of tin is obtained. This report concerns the synthesis and structural characterization of this novel substance.