Polyimide-silver nanocomposite containing phosphine oxide moieties in the main chain:Synthesis and properties

New flame-retardant polyimide-silver nanocomposite containing phosphine oxide moiety in the main chain was synthesized by a convenient ultraviolet irradiation technique.A precursor such as AgNO_3 was used as the source of the silver particles.Polyimide 6 as a source of polymer was synthesized by polycondensation reaction of bis（3-aminophenyl） phenyl phosphine oxide 4 with pyromellitic anhydride 5 in the presence of iso-quinoline as base and in m-cresol solution.The resulting composite film was characterized by FTIR spectroscopy,X-ray diffraction（XRD）,transmission electron microscopy（TEM）,thermogravimetry（TGA） and differential scanning calorimetry（DSC）.The average size of the nanometer Ag particles is about 10 nm.The temperature of 5 and 10%weight loss and also the char yield at 600℃of polyimide-silver nanocomposite 6a were higher than the pure PI 6.

A New Ternary Fluorescent Europium Complex with Bis(Diphenyl Phosphine Oxide) Methane and Thenoyltrifluoroacetone

A fluorescent ternary europium complex containing bis (diphenyl phosphine oxide) methane which functioned as both a neutral and anion ligand, and thenoyltrifluoroacetonato anion was synthesized and characterized by elemental analysis, DTA TG analysis, UV Vis, FT IR and MS spectroscopy. The chemical formula is proved to be Eu(TTA)(MPPO)(HMPPO)·(NO 3)·2H 2O. Its luminescence quantum efficiency(in acetonitrile, 26 3%) is approximately the same as that of the commonly used red emission luminescent compound, Eu(TTA) 3(TPPO) 2 (TPPO is triphenyl phosphine oxide). The new complex has comparatively long fluorescence lifetime.

Characterization of Metal Oxide-modified Walnut-shell Activated Carbon and Its Application for Phosphine Adsorption: Equilibrium, Regeneration, and Mechanism Studies

We prepared a kind of metal oxide-modified walnut-shell activated carbon(MWAC) by KOH chemical activation method and used for PH_3 adsorption removal. Meanwhile, the PH_3 adsorption equilibrium was investigated experimentally and fitted by the Toth equation, and the isosteric heat of PH_3 adsorption was calculated by the Clausius-Clapeyron Equation. The exhausted MWAC was regenerated by water washing and air drying. Moreover, the properties of five different samples were characterized by N_2 adsorption isotherm, SEM/EDS, XPS, and FTIR. The results showed that the maximum PH_3 equilibrium adsorption capacity was 595.56 mg/g. The MWAC had an energetically heterogeneous surface due to values of isosteric heat of adsorption ranging from 43 to 90 kJ/mol. The regeneration method provided an effective way for both adsorption species recycling and exhausted carbon regeneration. The high removal efficiency and big equilibrium adsorption capacity for PH_3 adsorption on the MWAC were related to its large surface area and high oxidation activity in PH_3 adsorption-oxidation to H_3 PO_4 and P_2 O_5. Furthermore, a possible PH_3 adsorption mechanism was proposed.

Chiral Phosphine Ligands Derived from Sugars8. Crystal and Molecular Structure of Diphenyl (methyl 4', 6'-O-benzylidene-2'-deoxy-α-D-altropyranoside-2-)phosphine Oxide

The crystal structure of the title compound, C26H27O6P, has been determined by single--crystal X-ray diffraction. The crystal is monoclinic with space groupP21, a=16. 193(l), b=5. 804(1), c=12. 512(2) A, β=93. 187(5)°, V=1174. 13A3, Dc=1. 319 g/cm3, F(000) =492, μ= 13. 52 cm-1, Z= 2, and final R= 0. 042and Rw= 0. 040 for 2349 reflections (I≥3σ(I)). Structure analysis revealed that thepyranose and 4, 6-O-benzylidene ring of the title compound adopts a distorted chair conformation.

SYNTHESIS AND CHARACTERIZATION OF POLY(PHTHALAZINONE ETHER PHOSPHINE OXIDE)S BY N-C COUPLING REACTION

Based on several unsymmetrical, twist, noncoplanar phthalazinone-containing monomers 2a-2e and an active bis（4-fluorophenyl）phenyl phosphine oxide （BFPPO） monomer, a series of novel poly（phthalazinone ether phosphine oxide）s （PPEPO） was synthesized by anhydrous K2CO3 mediated N-C coupling reaction in DMAc. The polymers exhibited good thermal properties with Tgs ranging from 267℃ to 306℃ and 5% weight loss temperatures in nitrogen higher than 430℃, together with high char yield upon prolonged heating at 800℃ （35%-56%）. Moreover, the polymers were readily soluble in common organic solvents, such as N-methyl-2-pyrrolidone, chloroform and m-cresol. These polymers had inherent viscosities in the range of 0.45-0.72 dL/g and could be cast into flexible and colorless films by spin coating or casting approach.

Chiral Phosphine Ligands Derived fro m Sugars .14 . Crystal Structure of Diphenyl( m ethyl4’,6’-O-benzylidene-3’-deoxy-α- D-altropyranoside-3-)phosphine Oxide

The crystal structure of the title compound, C 26 H 27 O 6P, has been determined by single crystal X ray diffraction analysis. The crystal is orthorhombic with space group P2 12 12 1, a=6.154(4), b=17.199(8), c=22.180(3) , V=2347.6 3, D c=1.32 g/cm 3, F(000)=984, μ=1.5 cm -1 , Z =4, and final R =0.075 and R w =0.080 for 1417 reflections (I≥3σ(I)) . The X ray diffraction analysis revealed that the structure of the title compound s similar to that of its parent phosphine and the pyranose and 4, 6 O benzylidene rings remain distorted chair conformations.

Mathematical model and reaction mechanism of molybdenum and tungsten extraction with TRPO from peroxide solution

To understand the behavior of molybdenum and tungsten extracted by tri-alkyl phosphine oxide(TRPO)from peroxide solution,the extraction mechanism was studied by slope method and Raman and FTIR spectroscopy.The empirical formulas of molybdenum and tungsten extraction distribution ratio(D_(Mo)and D_(W))as functions of equilibrium pH,TRPO concentration and temperature were obtained by establishing mathematical models.Furthermore,the reliability of the empirical formula was verified in the H^(+)-W-Mo-H_(2)O_(2) solution.The results indicate that the calculated values of D_(Mo)or D_(W)were consistent with the experimental values.The apparent extraction equilibrium constants of molybdenum and tungsten wereK_(Mo)^(app)=8.51×10^(3)(0.74≤pH_(e)≤1.7),K_(Mo)^(app)=99.89×10^(3)(1.7<pH_(e)≤4.62)andK_(W)^(app)=2.65×10^(3)(0.92<pH_(e)<2.16)at 20°C,respectively.The main extraction complex of molybdenum or tungsten was[H_(2)(Mo or W)_(2)O_(3)(O_(2))_(4)(H_(2)O)_(2)]·2TRPO.These empirical formulas can be used to analyze and estimate the extraction and separation of Mo and W from low molybdenum and tungsten concentration solutions.

High-performance liquid-phase catalytic purification of phosphine in tail gas using Pd(Ⅱ)/Cu(Ⅱ)composite

Pd/Cu liquid-phase composite was utilized as the catalyst in this study to remove PH_(3) at low temperatures.The anti-heterotoxicity of catalysts in the PH_(3) catalytic oxidation purification process was carefully explored and pioneered.The catalytic performance,thermodynamics,kinetics,and catalytic oxidation mechanism of Pd/Cu liquid-phase catalyst catalytic oxidation of PH_(3) were thoroughly investigated.The results showed that Pd/Cu has a superior catalytic effect on the removal of PH_(3) in the gas mixture under low temperature.With CO as the carrier gas,the removal efficiency of PH_(3) could be maintained at 100%for nearly 450 min,indicating that the Pd/Cu liquid phase catalyst has good resistance to heterotoxicity.According to the thermodynamic,kinetic,and related characterization results of the PH_(3) purification process,the kinetic region of the gas–liquid reaction of PH_(3) absorption by Pd/Cu solution was an interfacial reaction.Pd was the primary catalyst and Cu was the secondary catalyst,and the adsorption of PH_(3)was a primary reaction.PH_(3) was spontaneously oxidized to H_(3)PO_(4) in the Pd/Cu catalytic system during the removal process.Pd was regenerated by O_(2) and Cu,increasing the activity and stability of the Pd/Cu catalyst in the sustain and efficient purification of PH_(3) in tail gas.

Molecular engineering of an electron-transport triarylphosphine oxide-triazine conjugate toward high-performance phosphorescent organic light-emitting diodes with remarkable stability

Organic electron-transport materials are an essential component to boost performances and stability of organic light-emitting diodes. We present a robust organic electron-transport compound 3-(6-(3-(4,6-bis(4-biphenylyl)-1,3,5-triazin-2-yl)phenyl)pyridin-2-yl)phenyldiphenylphosphine oxide by facilely coupling the triphenylphosphine oxide moiety to the 2-phenyl-4,6-bis(4-biphenylyl)-1,3,5-triazine unit via a 2,6-pyridinylene linker. It is well soluble in weakly polar solvents and possesses a high Tg of 123 ℃ with an exceptional Td≈470 ℃ at 1% weight loss and deep HOMO/LUMO levels of ca.-6.45/-3.06 eV. The phosphorescent spectrum measured in solid state at 77 K reveals a notable triplet energy of 2.88 eV. n-Doping with 8-hydroxyquinolatolithium(Liq) produces the electron mobility value of 4.66×10-5–3.21×10-4 cm2 V-1 s-1@(2–5)×105 V cm-1.Moreover, the contrasting solubility of the bromo reaction intermediate and the new compound in alcoholic solvents facilitates separation. The characterizations of bottom-and top-emission green phosphorescent OLEDs involving this single Liq-doped electron-transport layer reveal long stability. In particular, the latter provides outstanding performances with 77.4 cd A–1(corresponding to an EQE of 18.7%) and 86.8 lm W–1@ca. 1000 cd m-2, based on the green emitter bis(2-phenylpyridine)(2-(4-methyl-3-phenylphenyl)pyridine)iridium(Ⅲ). Moreover, driven by a constant current for ca. 640 h, the initial luminance of 1000 cd m–2 appears almost no decay.

Synthesis of Bio-based Epoxy Containing Phosphine Oxide as a Reactive Additive Toward Highly Toughened and Fire-retarded Epoxy Resins

The integration of high mechanical toughness,impact strength as well as excellent flame-retardant properties toward epoxy resins(EPs)have always been a dilemma.The inadequate overall performance of EPs severely restricts their sustainable utilization in engineering aspects over long-term.Herein,a new bio-based agent(diglycidyl ether of magnolol phosphine oxide,referred as DGEMP)derived from magnolol(classified as lignan),extracted from natural plants Magnolia officinalis,was successfully synthesized and further employed as a flameretardant reactive additive to diglycidyl ether of bisphenol A(DGEBA).As demonstration,the composite resin,DGEBA/15DGEMP(15 wt%DGEMP),achieved an Underwriters Laboratories-94 V-0 rating with a high limiting oxygen index(LOI)value(41.5%).In cone calorimeter tests,it showed that heat release and smoke production were effectively inhibited during combustion,wherein the peak heat release rate(PHRR)value of DGEBA/15DGEMP was reduced by 50%compared to neat DGEBA.Additionally,it exhibited a superior tensile strength(82.8 MPa),toughness(5.11MJ/m^(3))and impact strength(36.5 k J/m^(2)),much higher than that of neat DGEBA(49.7 MPa,2.05 MJ/m^(3)and 20.9 k J/m^(2)).Thus,it is highly anticipated that DGEMP imparts significantly improved mechanical and fire-retarded properties to conventional EPs,which holds a great potential to address the pressing challenges in EP thermosets industry.

Influence of bidentate structure of an aryl phosphine oxide ligand on photophysical properties of its Eu~Ⅲ complex

The bidentate phosphine oxide ligand 1,8-bis(diphenylphosphino) naphthalene oxide (NAPO) and its EuⅢ complex 1 Eu(TTA)3(NAPO) (TTA=2-thenoyltrifluoroacetonate) were chosen to study the effect of bidentate phosphine oxide ligand on the photophysical properties of the corresponding complex. The intramolecular energy transfer processes of 1 were studied. The investigation showed that with bidentate structure NAPO could suppress solvent-induced quenching by enforcing the ligand-ligand interaction and the rigidi...

Synthesis and AO Resistant Properties of Novel Polyimide Fibers Containing Phenylphosphine Oxide Groups in Main Chain

A series of co-polyimide(PI)fibers containing phenylphosphine oxide(PPO)group were synthesized by incorporating the bis(4-aminophenoxy)phenyl phosphine oxide(DAPOPPO)monomer into the PI molecular chain followed by dry-jet wet spinning.The effects of DAPOPPO molar content on the atomic oxygen(AO)resistance of the fibers were investigated systematically.When the AO fluence increased from 0to 3.2×1020the mass loss of the fibers showed the dependence on DAPOPPO molar content in co-PI fibers.The PI fiber containing 40%DAPOPPO showed lower mass loss compared to those containing 0%and 20%DAPOPPO.At higher AO fluence,the higher DAPOPPO content gave rise to dense carpet-like surface of fibers.XPS results indicated that the passivated phosphate layer was deposited on the fiber surface when exposed to AO,which effectively prevented fiber from AO erosion.With the DAPOPPO content increasing from 0%to 40%,the retentions of tensile strength and initial modulus for the fibers exhibited obvious growth from 44%to 68%,and 59%to 70%,after AO exposure with the fluence of 3.2×1020The excellent AO resistance benefits the fibers for application in low Earth orbit as flexible construction components.

Triphenyl Phosphine Oxide and Carbazole-based Polymer Host Materials for Green Phosphorescent Organic Light-emitting Diodes

Four novel polymers, poly（3,6-9-decyl-carbazole-alt-1,3-benzene） （PB13CZ）, poly（3,6-9-decyl-carbazole-alt- bis（4-phenyl） （phenyl） phosphine oxide） （PTPPO38CZ）, poly（3,6-9-decyl-carbazole-alt-2,4-phenyl（diphenyl） phosphine oxide） （PTPPO13CZ） and poly（3,6-9-decyl-carbazole-alt-bis（3-phenyl） （phenyl） phosphine oxide） （PTTPO27CZ） were synthesized, and their thermal, photophysical properties and device applications were further investigated to correlate the chemical structures with the photoelectric performance of bipolar host materials for phosphorescent organic light emitting diodes. All of them show high thermal stability as revealed by their high glass transition temperatures and thermal decomposition temperatures at 5% weight loss. These polymers have wide band gaps and relatively high triplet energy levels. As a result, the spin coating method was used to prepare the green phosphorescent organic light emitting diodes with polymers PTPPO38CZ, PTPPO13CZ and PTTPO27CZ as the typical host materials. The green device of polymer PTPPO38CZ as host material shows electroluminescent performance with maximum current efficiency of 2.16 cd.A-1, maximum external quantum efficiency of 0.7%, maximum brightness of 1475 cd.m-2 and reduced efficiency roll-off of 7.14% at 600 cd.m-2, which are much better than those of the same devices hosted by polymers PTTPO27CZ and PTPPO13CZ.

Direct synthesis of α-hydroxyketone phosphates from terminal alkynes and H-phosphine oxides in the presence of PhI(OAc)2 and H2O

A simple and highly efficient one-pot method for the construction of α-hydroxyketone phosphates from terminal alkynes and H-phosphine oxides has been developed in the presence of PhI（OAc）2 and H20. The present protocol provides an attractive approach to α-hydroxyketone phosphates in good to high yields, with the advantages of operation simplicity, the use of commercially available materials, broad substrate scope, high atom efficiency and good tolerance to scale-up synthesis.

Cu/Picolinamides-Catalyzed Coupling of (Hetero) aryl Halides with Secondary Phosphine Oxides and Phosphite

Some 4-hydroxy-picolinic acid derived amides were revealed as more efficient ligands for Cu-catalyzed coupling of(hetero)aryl halides with secondary phosphine oxides and phosphites.Only 3—5 mol%CuI and ligands were required to ensure coupling with a number of(hetero)aryl bromides and iodides to complete at 120 ℃ in 10—20 h.

Nickel-catalyzed kinetic resolution to achieve P-chiral phosphine oxides and sec-phosphine oxides

P-Chiral phosphines and sec-phosphine oxides(SPO) are found in a diverse range of compounds that play crucial roles in various fields, including asymmetric catalysis, materials, agrochemistry, and pharmaceutical chemistry. Herein, we describe an enantioselective Ni-catalyzed kinetic resolution of racemic sec-phosphine oxides to obtain the corresponding optically pure Pchiral phosphine oxides and sec-phosphine oxides, respectively. These products are versatile chiral phosphine building blocks that can be used to construct an extensive range of P-chiral phosphines.

Metal-free reduction of tertiary phosphine oxides with Hantzsch ester

The （COCl）2/Hantzsch ester is found to be an effective system for the metal-free reduction of tertiary phosphine oxides. The reaction proceeds under mild conditions, and is applicable to triarylphosphine oxides and alkyldiarylphosphine oxides to produce the corresponding tertiary phosphines in good to excellent yields. This new finding provides a practical, convenient and metal-free method for the reduction of tertiary phosphine oxides to tertiary phosphines, and shows potential application in organic synthesis.

Organophosphorus catalytic reaction based on reduction of phosphine oxide

The special electronic configuration of phosphorus atoms endows organophosphorus reagents with unique chemical properties,which enable them to be used to catalyze various organic reactions,such as the Wittig reaction,Staudinger reaction,Appel reaction and Mitsunobu reaction.However,the catalytic process will be accompanied by the generation of large amounts of phosphine oxide waste,resulting in the reduction of atom utilization of the reaction,and it is difficult to separate the product.Therefore,it is essential to explore a greener and more sustainable organic synthesis route based on the catalytic cycle of phosphine oxide as a model.This paper summarizes the catalytic cycle and recycling of phosphorus with or without reducing agents and reviews the related developments in recent decades:from the addition of stoichiometric strong reducing agents,to the design of ring phosphines with specific structures,to the development of new energy inputs(electrochemistry),to the addition of a series of compounds to activate the P(V)––O double bond,driving the catalytic cycle of phosphine oxide through chemical transformation.This review also points out the development potential of this field in the future,which will promote its development and progress in a greener direction.

Inclusion property and Diels-Alder reaction of bis (diphenylphosphine oxide) butadiyne

The host molecule, bis (diphenylphosphine oxide) butadiyne (2), includes a variety of guests to form five complexes (2a—2e). In addition, the Diels-Alder reaction between 2 and anthracene gives 9, 9′, 10, 10′-tetrahedron-9, 9′, 10, 10′-bi-ethenoantracene-11, 11′-bis (diphenylphosphine oxide) (3) which is a potential di-π-methane reactant and can undergo photorearrangement.

含氟膦氧衍生物修饰的纯蓝光钙钛矿发光二极管

实现高效蓝色电致发光是钙钛矿发光二极管(PeLEDs)商业应用的关键挑战,特别是波长为465~475 nm的纯蓝光。蓝光PeLEDs的低效率主要源于混合卤素策略导致的高缺陷密度和降维策略导致的载流子注入困难。本文以氯/溴混合卤素准二维钙钛矿为研究对象,探究了小分子添加剂膦氧衍生物((五氟苯基)甲基)二苯基氧化膦(PFPO)在钙钛矿前驱体溶液中的作用机理及其对钙钛矿薄膜形貌、光学和器件性能的影响。实验结果显示,PFPO修饰后的钙钛矿薄膜光致发光强度和寿命均有增加,说明PFPO具有良好的缺陷钝化能力。紫外-可见光吸收光谱证实修饰后薄膜中小n相吸收强度明显降低,说明小n相得到了显著抑制,减少了非辐射复合路径,同时有利于激子能量转移。器件结果表明,PFPO处理后的PeLEDs器件最大外量子效率从1.83%提升到3.62%,发光峰位于466 nm,对应的CIE为(0.123,0.079),与标准蓝光CIE坐标(0.131,0.046)接近。