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 sourc...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.展开更多
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 e...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.展开更多
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 phosp...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.展开更多
A phosphrous-containing poly(aryl ether ketone) was synthesized derived from bisphenol-A and bis[4-(4- fluorobenzoyl)phenyl] phenyl phosphine oxide (FPPPO) by nucleophilic substitution reaction. The structure of...A phosphrous-containing poly(aryl ether ketone) was synthesized derived from bisphenol-A and bis[4-(4- fluorobenzoyl)phenyl] phenyl phosphine oxide (FPPPO) by nucleophilic substitution reaction. The structure of the polymer was characterized by FT-IR, ^1H-NMR and ^31p-NMR. The thermal property of the PAEK was measured by DSC and TGA. The glass transition temperature (Tg) of the polymer was 205℃, and the 5% weight loss temperature under nitrogen was 475℃. Good solubility of the polymer in organic solvents, such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide and chloroalkanes was observed, flexible film was obtained from the polymer's CH2Cl2 solution. The limiting oxygen index (LOI) of the PAEK was 40, which indicated that organic phosphorus moiety can offer good flame retardant property to the polymer.展开更多
In this work, an experimental study was carried out to find the best-operating conditions for the study of the extraction percentage (%E) and the separation factor (SF) of La(III) and Ce(III) complexes. To carry out t...In this work, an experimental study was carried out to find the best-operating conditions for the study of the extraction percentage (%E) and the separation factor (SF) of La(III) and Ce(III) complexes. To carry out this study, a variation of <em>β</em>-diketone concentrations was used, keeping the concentration of tri-octyl phosphine oxide (TOPO) continuous at 0.05 M. The ratio of organic phase to the aqueous phase (O/A) was also studied. The %E and SF were analyzed and compared in the 1,1,1-trifluoro-2, 4-pentanedione (TFA) with TOPO, and 1,1,1,5,5,5-Hexafluoro-2,4-pentanedione (HFAc) with TOPO in Ionic Liquid (IL) and Kerosene. The one-stage extraction efficiency in IL of La(III) and Ce(III) complexes was 42.13% and 77.48% for the TFA-TOPO system and La(III) and Ce(III) complexes were 94.33% and 97.67% for the HFAc-TOPO system. While the SF between Ce(III) and La(III) complexes was 4.91 for TFA-TOPO and 2.64 for HFAc-TOPO. On the other hand, the one-stage extraction efficiency in Kerosene of La(III) and Ce(III) complexes was 27.57% and 63.70% in the TFA-TOPO system. The one-stage extraction efficiency of La(III) and Ce(III) complexes were 99.87% and 99.73% for the HFAc-TOPO system in Kerosene while the SF between Ce(III) and La(III) complexes was 4.62 for TFA-TOPO and 0.49 for HFAc-TOPO. The main conclusion was that using two extractants (<em>β</em>-diketone and TOPO) produced a synergistic effect improving the extraction capacity and SF of La(III) and Ce(III) complexes for both systems in IL and Kerosene.展开更多
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 restri...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.展开更多
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 chemi...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.展开更多
Aging of a solid composite propellant containing HTPB/AP/AL was performed in order to validate the conformance of the accelerated aging data to the Arrhenius law. The main objective of the work was to examine the infl...Aging of a solid composite propellant containing HTPB/AP/AL was performed in order to validate the conformance of the accelerated aging data to the Arrhenius law. The main objective of the work was to examine the influence of the aziridine bonding agents family on the propellant aging. Aging of the prepared propellant samples was conducted as follows: 1. Four samples, one free of bonding agents, and three containing aziridine based bonding agents MAPO,HX-752, MAT4 were aged at 65°C. 2. Another four samples based on HX-752, MAT4 with different curing agents were aged at 65°C. The measured mechanical properties of the free bonding agent propellant samples were very far from the specifications and this illustrates the importance of the bonding agents in both the preparation and the aging phases.The prepared bonding agent 'MAT4' gave remarkable improvements of the mechanical properties comparing with HX-752 and MAPO. The aziridine bonding agents family inhibited the rate of decomposition of the propellant during the aging periods and supported the propellant matrix against decomposition at the elevate temperatures. Using of HMDI as curing agent gave slight better mechanical properties to the IPDI.展开更多
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,...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.展开更多
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-biphenyl...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.展开更多
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 o...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...展开更多
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(d...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.展开更多
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 r...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.展开更多
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 ...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.展开更多
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′-tetra...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.展开更多
The Ni-Al bimetallic catalysis of intramolecular enantioselective and regioselective C-H cyclization of4-oxoquinazolines with tethered alkenes has been successfully developed.Some new secondary phosphine oxides(SPOs)w...The Ni-Al bimetallic catalysis of intramolecular enantioselective and regioselective C-H cyclization of4-oxoquinazolines with tethered alkenes has been successfully developed.Some new secondary phosphine oxides(SPOs)with large steric hindrance(SPO6-11)were designed and successfully synthesized from readily available chiral amines or amino acids.The developed chiral SPOs as ligands or preligands demonstrate much higher efficiency in the asymmetric catalytic reactions than the reported traditional ones.A new class of chiral tricyclic pyrroloquinazolinones were obtained in up to 95%yield and 99%ee.展开更多
Unraveling the catalytic reaction mechanism is a long-term challenge for developing efficient catalysts.The blooming bimetallic catalyst have enabled to activate inert bonds and realize complex C-C formation.Herein,we...Unraveling the catalytic reaction mechanism is a long-term challenge for developing efficient catalysts.The blooming bimetallic catalyst have enabled to activate inert bonds and realize complex C-C formation.Herein,we theoretically discover a dual-phosphinito bridged hetero-bimetallic species that verified by NMR experiments.Our results indicate only dual-phosphinito Ni-Al model can be an active catalyst in asymmetric cycloadditions via C-C activation and C-H activation,which can well rationalize the experimental observations for both reactivity and stereo-selectivity.An unprecedented tandem redox dehydrogenation mechanism was revealed to control the formation of this active species overriding the inherent basicity.Synergistic Lewis acid and eg orbital interactions,including dz2 orbital reoccupation and d_(x^(2)−y^(2))orbital recombination,were disclosed to understand both thermodynamic and kinetic advance of dual-bridged model,displaying feasible redox properties.展开更多
The numerical calculations for Am multistage fractional extraction by trialkyl phosphine oxide (TRPO) were verified by a hot test. 1750L/t-U high level waste (HLW) was used as the feed to the TRPO process. The analysi...The numerical calculations for Am multistage fractional extraction by trialkyl phosphine oxide (TRPO) were verified by a hot test. 1750L/t-U high level waste (HLW) was used as the feed to the TRPO process. The analysis used the simple objective function to minimize the total waste content in the TRPO process streams. Some process parameters were optimized after other parameters were selected. The optimal process parameters for Am extraction by TRPO are: 10 stages for extraction and 2 stages for scrubbing; a flow rate ratio of 0.931 for extraction and 4.42 for scrubbing; nitric acid concentration of 1.35mol/L for the feed and 0.5mol/L for the scrubbing solution. Finally, the nitric acid and Am concentration profiles in the optimal TRPO extraction process are given.展开更多
文摘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.
文摘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.
基金supported by the National Natural Science Foundation of China(Nos.50673031 and 50973036)
文摘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.
基金This work was supported by the National Natural Science Foundation of China(No.50203008).
文摘A phosphrous-containing poly(aryl ether ketone) was synthesized derived from bisphenol-A and bis[4-(4- fluorobenzoyl)phenyl] phenyl phosphine oxide (FPPPO) by nucleophilic substitution reaction. The structure of the polymer was characterized by FT-IR, ^1H-NMR and ^31p-NMR. The thermal property of the PAEK was measured by DSC and TGA. The glass transition temperature (Tg) of the polymer was 205℃, and the 5% weight loss temperature under nitrogen was 475℃. Good solubility of the polymer in organic solvents, such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide and chloroalkanes was observed, flexible film was obtained from the polymer's CH2Cl2 solution. The limiting oxygen index (LOI) of the PAEK was 40, which indicated that organic phosphorus moiety can offer good flame retardant property to the polymer.
文摘In this work, an experimental study was carried out to find the best-operating conditions for the study of the extraction percentage (%E) and the separation factor (SF) of La(III) and Ce(III) complexes. To carry out this study, a variation of <em>β</em>-diketone concentrations was used, keeping the concentration of tri-octyl phosphine oxide (TOPO) continuous at 0.05 M. The ratio of organic phase to the aqueous phase (O/A) was also studied. The %E and SF were analyzed and compared in the 1,1,1-trifluoro-2, 4-pentanedione (TFA) with TOPO, and 1,1,1,5,5,5-Hexafluoro-2,4-pentanedione (HFAc) with TOPO in Ionic Liquid (IL) and Kerosene. The one-stage extraction efficiency in IL of La(III) and Ce(III) complexes was 42.13% and 77.48% for the TFA-TOPO system and La(III) and Ce(III) complexes were 94.33% and 97.67% for the HFAc-TOPO system. While the SF between Ce(III) and La(III) complexes was 4.91 for TFA-TOPO and 2.64 for HFAc-TOPO. On the other hand, the one-stage extraction efficiency in Kerosene of La(III) and Ce(III) complexes was 27.57% and 63.70% in the TFA-TOPO system. The one-stage extraction efficiency of La(III) and Ce(III) complexes were 99.87% and 99.73% for the HFAc-TOPO system in Kerosene while the SF between Ce(III) and La(III) complexes was 4.62 for TFA-TOPO and 0.49 for HFAc-TOPO. The main conclusion was that using two extractants (<em>β</em>-diketone and TOPO) produced a synergistic effect improving the extraction capacity and SF of La(III) and Ce(III) complexes for both systems in IL and Kerosene.
基金Anhui Provincial Natural Science Foundation for Distinguished Young Scholar(No.2008085J26)Natural Science Foundation in University of Anhui Province(Nos.KJ2021ZD0119 and 2022AH040251)+3 种基金China Scholarship Council(No.202008340021)Start-up Fund for Distinguished Scholars in Hefei University(No.20RC37)Anhui Provincial Natural Science Foundation(No.2108085QB47)Research Grants Council of the Hong Kong Special Administrative Region(No.City U 11208617)。
文摘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.
基金supported by the National Natural Science Foundaiton of China (22171119)Gansu Province Science and Technology Plan for major projects (21ZD4WA021)key research plan (21YF5WA114)。
文摘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.
文摘Aging of a solid composite propellant containing HTPB/AP/AL was performed in order to validate the conformance of the accelerated aging data to the Arrhenius law. The main objective of the work was to examine the influence of the aziridine bonding agents family on the propellant aging. Aging of the prepared propellant samples was conducted as follows: 1. Four samples, one free of bonding agents, and three containing aziridine based bonding agents MAPO,HX-752, MAT4 were aged at 65°C. 2. Another four samples based on HX-752, MAT4 with different curing agents were aged at 65°C. The measured mechanical properties of the free bonding agent propellant samples were very far from the specifications and this illustrates the importance of the bonding agents in both the preparation and the aging phases.The prepared bonding agent 'MAT4' gave remarkable improvements of the mechanical properties comparing with HX-752 and MAPO. The aziridine bonding agents family inhibited the rate of decomposition of the propellant during the aging periods and supported the propellant matrix against decomposition at the elevate temperatures. Using of HMDI as curing agent gave slight better mechanical properties to the IPDI.
基金support of this work from the National Science Foundation of China(Nos.21602123,21702121 and 21971143)the 111 Project(No.D20015)the Foundation of Hubei Three Gorges Laboratory(No.SC213008).
文摘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.
基金supported by the National Key Research and Development Program of China (2016YFB0400701)Natural Science Foundation of Guangdong Joint Program (U1801258, U1301243)Department of Science and Technology of Guangdong Province (2019B010924003)。
文摘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.
基金Project supported by the National Natural Science Foundation of China (90406021, 50903028)Science and Technology Bureau of Heilongjiang Province (QC08C10)
文摘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...
基金financially supported by the Major Research Program from the State Ministry of Science and Technology(No.2012CB933301)the National Natural Science Foundation of China(No.21574068)+3 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(No.YX03001)Natural Science Foundation of Jiangsu Province(No.BM2012010)Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.15KJB150022)Jiangsu Government Scholarship for Overseas Studies
文摘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.
基金The authors are grateful to Chinese Academy of Sciences(supported by the Strategic Priority Research Program,grant XDB20020200&QYZDJ-SSW-SLH029)the National Natural Science Foundation of China(grant 21621002,21831009 and 21991110)for their financial support.
文摘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.
基金the Natural Science Foundation of China(Nos.21021001,21072134 and J1103315/J0104)for financial support
文摘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.
基金Project supported by the National Natural Science Foundation of China (No. 29572054) and the Natural Science Foundation of Tianjin (No. 963604711).
文摘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.
基金the National Natural Science Foundation of China(No.22071270)Science and Technology Program of Guangzhou(20220602JBGS02)+1 种基金Guangdong Province Zhu Jiang Talents Plan(No.2016ZT06C090)Guangzhou City Talents Plan(No.CYLJTD201609)for financial support。
文摘The Ni-Al bimetallic catalysis of intramolecular enantioselective and regioselective C-H cyclization of4-oxoquinazolines with tethered alkenes has been successfully developed.Some new secondary phosphine oxides(SPOs)with large steric hindrance(SPO6-11)were designed and successfully synthesized from readily available chiral amines or amino acids.The developed chiral SPOs as ligands or preligands demonstrate much higher efficiency in the asymmetric catalytic reactions than the reported traditional ones.A new class of chiral tricyclic pyrroloquinazolinones were obtained in up to 95%yield and 99%ee.
基金We gratefully acknowledge the National Key Research and Development Program of China(No.2021YFA1500100)the National Natural Science Foundation of China(Nos.92156017,21890722,22188101)+2 种基金the NSF of Tianjin Municipality(No.19JCJQJC62300)Tianjin Research Innovation Project for Postgraduate Students(No.2019YJSB081)Haihe Laboratory of Sustainable Chemical Transformation of Tianjin for generous financial support.
文摘Unraveling the catalytic reaction mechanism is a long-term challenge for developing efficient catalysts.The blooming bimetallic catalyst have enabled to activate inert bonds and realize complex C-C formation.Herein,we theoretically discover a dual-phosphinito bridged hetero-bimetallic species that verified by NMR experiments.Our results indicate only dual-phosphinito Ni-Al model can be an active catalyst in asymmetric cycloadditions via C-C activation and C-H activation,which can well rationalize the experimental observations for both reactivity and stereo-selectivity.An unprecedented tandem redox dehydrogenation mechanism was revealed to control the formation of this active species overriding the inherent basicity.Synergistic Lewis acid and eg orbital interactions,including dz2 orbital reoccupation and d_(x^(2)−y^(2))orbital recombination,were disclosed to understand both thermodynamic and kinetic advance of dual-bridged model,displaying feasible redox properties.
基金the Major Research Project of the Ninth-Five Plan(1996 2 0 0 0 ) of China!(No:96 - A18- 0 2 - 0 1)
文摘The numerical calculations for Am multistage fractional extraction by trialkyl phosphine oxide (TRPO) were verified by a hot test. 1750L/t-U high level waste (HLW) was used as the feed to the TRPO process. The analysis used the simple objective function to minimize the total waste content in the TRPO process streams. Some process parameters were optimized after other parameters were selected. The optimal process parameters for Am extraction by TRPO are: 10 stages for extraction and 2 stages for scrubbing; a flow rate ratio of 0.931 for extraction and 4.42 for scrubbing; nitric acid concentration of 1.35mol/L for the feed and 0.5mol/L for the scrubbing solution. Finally, the nitric acid and Am concentration profiles in the optimal TRPO extraction process are given.