Tetraphenyl Ester Research Articles

Solubilities of Three Phosphorus Flame Retardants in Selected Organic Solvents

Using a static analytical method, the solubilities of phosphonic acid, P,P′-(1,4-piperazinediyl)bis-P,P,P′,P′-tetraphenyl ester (PAPBE), N,N′-[1,3-phenylenebis(methylene)]bis(phosphoramidic acid)P,P,P′,P′-tetraphenyl ester (PNBE), and 4-(hydroxymethyl)-1-oxido-2,6,7-trioxa-1-phosphabicyclo [2.2.2] octane (PEPA) were measured from 293.15 K to 343.15 K in four selected organic solvents. Several thermodynamic models were used to correlate the experimental solubility data, such as Scatchard–Hildebrand, Wilson, nonrandom two-liquid (NRTL), and UNIQUAC. The calculated results showed that all the models reproduced the experimental data very well, and the UNIQUAC equation gives the best correlation. Using the group contribution methods, the solubility parameters of phosphorus flame retardants can be calculated, which were compared with the previous values calculated with the Scatchard–Hildebrand model.

Solid–Liquid Phase Equilibrium of Phosphoramidic acid, N,N′-1,2-Ethanediylbis-P,P,P′,P′-tetraphenyl Ester in Selected Solvents

Phosphoramidic acid, N,N′-1,2-ethanediylbis-P,P,P′,P′-tetraphenyl ester (PAETE) was prepared and characterized by elemental analysis (EA), mass spectra (MS), infrared spectroscopy (IR), and nuclear magnetic resonance (NMR). The thermostability of PAETE was measured via thermogravimetric analysis (TGA). The melting temperature and the fusion enthalpy of PAETE were evaluated by differential scanning calorimeter (DSC). The solubilities of PAETE in ten selected solvents were obtained using a gravimetric method. The experimental data were well correlated by the Buchowski–Ksiazczak (λh), Scatchard–Hildebrand, modified Apelblat model, and the ideal equations. The solubility parameter of PAETE was estimated by the Scatchard–Hildebrand Model. The dissolution enthalpy and entropy of PAETE in the ten selected solvents were also calculated by the modified Apelblat model.

Synthesis and thermal kinetic study of phosphoric acid, P, P′-1, 4-phenylene P, P, P′, P′-tetraphenyl ester

A phosphorous flame retardant of phosphoric acid, P, P′-1, 4-phenylene P, P, P′, P′-tetraphenyl ester (PAPTE) was synthesized by diphenyl chlorophosphate and hydroquinone. The structural features of PAPTE were investigated with mass spectrometry, infrared spectroscopy, X-ray powder diffraction and nuclear magnetic resonance methods. The thermal behavior of PAPTE was carried out with thermogravimetric (TG) analysis instruments. The kinetic parameters, including the activation energy and pre-exponential factor of the decomposition process for the title compound, were calculated through the Friedman method, the Kissinger–Akahira–Sunose method and the Flynn–Wall–Ozawa method, while the thermal decomposition mechanism was also studied with the invariant kinetic parameters (IKP) method based on a set of TG data obtained at different heating rates. It was shown that the activation energies calculated for the decomposition reaction by different methods were found to be consistent with the conversion functions calculated by means of the IKP method which depend on a set of kinetic methods.

Solubilities of phosphoric acid, P,P′-1,4-phenylene P,P,P′,P′-tetraphenyl ester in the organic solvents

A phosphorous flame retardant of phosphoric acid, P,P′-1,4-phenylene P,P,P′,P′-tetraphenyl ester (PAPTE) was synthesized by diphenyl chlorophosphate and hydroquinone. The structural features of PAPTE were investigated with mass spectra (MS), infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) and high-performance liquid chromatograph (HPLC) methods. The thermal behavior of PAPTE was analyzed with differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA) instruments. A static analytic method was used to measure the solubilities of PAPTE in the several selected pure solvents, which are methanol, ethanol, acetone, ethyl acetate, acetonitrile, methyl acetate, toluene, ether, n-propanol, i-propanol, where the temperatures range is from 288.25 to 333.45K. The experiments were also performed in the binary mixed solvents of acetone and methanol. Several thermodynamic models were used to correlate the experimental solubility data, such as Wilson, nonrandom two-liquid (NRTL), UNIQUAC equations. The solubility data of PAPTE in binary solvents were correlated with the modified Wilson model. The calculated results showed that those models can excellently reproduce the experimental data and the UNIQUAC equation reveals the better ability in correlation. Using the Scatchard–Hildebrand methodology, the activity coefficients, solubility parameter of the solute and the partial molar excess enthalpies at infinite dilution were calculated.

Solid–Liquid Phase Equilibria of N,N′-[1,3-Phenylenebis(methylene)]bis(phosphoramidic acid) P,P,P′,P′-Tetraphenyl Ester in 10 Pure Solvents

N,N′-[1,3-Phenylenebis(methylene)]bis(phosphoramidic acid) P,P,P′,P′-tetraphenyl ester (PNBE) was synthesized and characterized by elemental analysis, mass spectrometry, and IR and NMR spectroscopy. The melting point and the enthalpy of fusion of PNBE were obtained by differential scanning calorimetry, and the thermal stability of PNBE was measured by thermogravimetric analysis. The solubilities of PNBE in selected solvents were determined by a gravimetric method. The experimental data were correlated with the Wilson, nonrandom two-liquid (NRTL), and universal quasichemical (UNIQUAC) equations. The calculated results showed good agreement with the experimental data. Among them, the Wilson model gave the best description of the solubility data. The solubility parameter of PNBE was evaluated using the Scatchard–Hildebrand model. The data presented in this work will be helpful for the choice of solvents for the solution-casting process and optimization of the dissolution or purification of PNBE.

Solubilities of Phosphonic Acid, P,P′-(1,4-Piperazinediyl)bis-,P,P,P′,P′-tetraphenyl Ester in Selected Solvents

Phosphonic acid, P,P′-(1,4-piperazinediyl)bis-,P,P,P′,P′-tetraphenyl ester (PAPBE), as a versatile flame retardant, was prepared by a literature method. The solubilities of PAPBE in selected solvents have been measured under a range of temperatures from 283.15 K to 343.15 K. The experimental data were correlated with the Buchowski–Ksiazczak (λh), Scatchard–Hildebrand, Wilson, nonrandom two liquid (NRTL), and universal quasichemical (UNIQUAC) equations. The calculated results showed good agreement with the experimental data. The differential values of enthalpy and entropy of dissolution at saturation were also calculated by the van’t Hoff equation. Toluene and acetone are shown to be good candidates as reaction solvents that can be applied to optimize the reactive crystallization process.

Solid–Liquid Phase Equilibrium of N,N′-(Methylenedi-4,1-phenylene)bis(phosphoramidic acid) Tetraphenyl Ester in Selected Solvents

N,N′-(Methylenedi-4,1-phenylene)bis(phosphoramidic acid) tetraphenyl ester (PNBTE), a flame retardant with high thermal stability, was synthesized and characterized by elemental analysis (EA), mass...

Liquid state membrane electrode sensitive to Ln(III)

A liquid ion-exchange electrode containing a chloroform solution of the complex of Ln(III) (Gd, La) with tetraphenyl ester of imidodiphosphoric acid is described. The slope of the calibration graph (electrode potential vs concentration) is 18.5 mV/pLn in the pLn range 4.7-2 (pH = 5). Fe(III), Al(III), Co(II), Ni(II) and Ca(II) ions do not interfere, unlike ions of other lanthanides. It was found that the electrode might be applied to detect the end point of the titration of Ln 3+ ions.

Interaction of covalent fluorides and imidodiphosphoric acid tetraphenyl ester

The weak acid imidodiphosphoric acid tetraphenylester, (PhO) 2 P(O)NHP(O)(OPh) 2, LH, is capable to act as bidentate ligand. With M(II) and M(III) cations it forms neutral chelate complexes, in which the coordination of the ligand occurs through the two phosphoryl oxygen atoms, [1–3]. Covalent fluorides such as TaF 5 and TiF 4 react with thls ligand in its neutral as well as in its anionic form, We have been able to prove the formation of the complexes (TaF 5) 2LH, TaF 5LH, TaF 5L −, TiF 4LH, and TiF 4L − by means of 19F-n.m.r. spectroscopy, Additional complexes formed by substitution of fluoride are TaF 4L, TaF 3L 2 and TiF 2L 2. Among them TaF 3L 2 and TiF 2L 2 seem to be the most stable complexes. They can be obtained exclusively at high ligand concentrations. The relations between the structure of the octehedral complexes and n.m.r. data established by Il'in and Buslaev [4] can be confirmed.

Diels-alder reactions of azodiphosphonic acid, tetraphenyl ester

Diels-alder reactions of azodiphosphonic acid, tetraphenyl ester