A new method for generating reactive species to destroy toxic organic chemicals has been developed. This method reacts yellow phosphorus with O_2, in moist air to produce species such as O,O_3, PO, and PO_2, which are...A new method for generating reactive species to destroy toxic organic chemicals has been developed. This method reacts yellow phosphorus with O_2, in moist air to produce species such as O,O_3, PO, and PO_2, which are capable of reacting with various types of organics. Toxic organic com-pounds are converted to small molecular wight organic acids, aldehydes, and/or alcohols, while yel-low phosphonis is oxidital into phosphoric acid, which may be recovered as a valuable byproduct.This technique has ben demonstrated to be effective for destroying many types of toxic organiccompounds. including PAH, aromatic chlorides, amines, alcohols, and acids, nitro-aromatics,heterocyclic hydrocarbons, PCB, aliphatic chlorides and sulfides, dyes, and pesticides.展开更多
2-methoxy-6-oxo-1, 4, 2-diazaphosphorinane-2-oxide 8, phosphorus counterpart of 2, 6-dioxopiperazine, was synthesized as antitumor agent. The new phosphorus heterocycle compound 8 is the key intermediate in the synthe...2-methoxy-6-oxo-1, 4, 2-diazaphosphorinane-2-oxide 8, phosphorus counterpart of 2, 6-dioxopiperazine, was synthesized as antitumor agent. The new phosphorus heterocycle compound 8 is the key intermediate in the synthesis of phosphorus counterpart of bisdioxopiperazine.展开更多
Using cation exchange resin(D72,Amberlyst-15) as catalyst, Mannich-type reaction of 5-amino-1,2,4-triazole 1, containing guanidine substructure, provides an efficient synthesis of a new kind of bicyclic P- and N-conta...Using cation exchange resin(D72,Amberlyst-15) as catalyst, Mannich-type reaction of 5-amino-1,2,4-triazole 1, containing guanidine substructure, provides an efficient synthesis of a new kind of bicyclic P- and N-containing compounds, 6-phospha-4,5,6-trihydroimidazolo [2,3-e] 1,2,4-triazole 4.展开更多
Arbuscular mycorrhizal (AM) fungi penetrate the cortical cells of the roots of vascular plants, and are widely distributed in soil. The formation of these symbiotic bodies accelerates the absorption and utilization ...Arbuscular mycorrhizal (AM) fungi penetrate the cortical cells of the roots of vascular plants, and are widely distributed in soil. The formation of these symbiotic bodies accelerates the absorption and utilization of min- eral elements, enhances plant resistance to stress, boosts the growth of plants, and increases the survival rate of transplanted seedlings. We studied the effects of various arbuscular mycorrhizae fungi on the growth and devel- opment of licorice (Glycyrrhiza glabra). Several species of AM, such as Glomus mosseae, Glomus intraradices, and a mixture of fungi (G. mosseae, G intraradices, G. cladoideum, G microagregatum, G caledonium and G. etunica- tum) were used in our study. Licorice growth rates were determined by measuring the colonization rate of the plants by the fungi, plant dry biomass, phosphorus concentration and concentration of secondary metabolites. We estab- lished two cloned strains of licorice, clone 3 (C3) and clone 6 (C6) to exclude the effect of genotypic variations. Our results showed that the AM fungi could in fact increase the leaf and root biomass, as well as the phosphorus con- centration in each clone. Furthermore, AM fungi significantly increased the yield of certain secondary metabolites in clone 3. Our study clearly demonstrated that AM fungi play an important role in the enhancement of growth and development of licorice plants. There was also a significant improvement in the secondary metabolite content and yield of medicinal compounds from the roots.展开更多
Seventy organic compounds including various organophosphorus esters, amines and oxygen-based ligands were investigated as extractants. The experiment results show that amines are excellent extractants for W and Mo. Th...Seventy organic compounds including various organophosphorus esters, amines and oxygen-based ligands were investigated as extractants. The experiment results show that amines are excellent extractants for W and Mo. Their sequence of extraction ability for W is as follows: quarternary amine > tertiary amine > secondary amine > primary amine. Acidic organophosphorus extractants do not extract W, but can extract Mo with high extraction ability from the acidic solution. These extractants could provide a potential process for separating W from Mo.展开更多
An electron-addition, under single-crystal conditions, to pentavalent phosphorus compounds as Cl-P (=O, S) Y, Z with the P-Cl bond as electron-accepting group, is selected as an additional model for SN2(P) like reacti...An electron-addition, under single-crystal conditions, to pentavalent phosphorus compounds as Cl-P (=O, S) Y, Z with the P-Cl bond as electron-accepting group, is selected as an additional model for SN2(P) like reactions. It is demonstrated that the geometric information stored in the tetrahedral configuration (substrate) can be transmitted in the corresponding trigonal bipyramidal (TBP) state for nucleophilic substitution. In this article, we focus on these specific mechanistic aspects of carbon and phosphorus. We consider our study as a contribution to the significance of these (bio)chemical intermediates.展开更多
The LPE growth of quaternary InAs11-x-yPxSby with x = 0.2 and y = 0.09 on InAs substrate has been studied. This composition is very suitable for the laser and detector applications at about 2.5 μm. We show that in In...The LPE growth of quaternary InAs11-x-yPxSby with x = 0.2 and y = 0.09 on InAs substrate has been studied. This composition is very suitable for the laser and detector applications at about 2.5 μm. We show that in InAsPSb/InAs system there is a determinate relation between the surface morphology and the lattice mismatch of the epi-wafers, by which we can easily control the melt composition to grow high quality hetero-structures. The reason has been discussed. The p-n junctions with fairly good carrier profile have been prepared in this system.展开更多
Introduction: Organ phosphorus (OP) toxicity has been studied extensively because of its world wide use. Toxicity of organophosphates is the result of inhibition of acetyl cholinesterase resulting in cholinergic signs...Introduction: Organ phosphorus (OP) toxicity has been studied extensively because of its world wide use. Toxicity of organophosphates is the result of inhibition of acetyl cholinesterase resulting in cholinergic signs. Aim of the Work: To evaluate initial indicators that can indicate prognosis of patients in OP poisoning. Materials and Methods: A retrospective study conducted in Zagazig university hospital over a year. OP poisoning was clinically diagnosed with history of OP compound exposure and confirmed by low pseudo cholinesterase levels. Results: In the present study, 76 patients were enrolled. Major cases were male. High mortality rates were in the youth and in prolonged ventilated patients. The mortality rate was proportionally related to lag time after exposure and plasma pseudo cholinesterase levels. Electrolyte disturbance did not affect clinical outcome. Conclusion: From this study, it could be concluded that mortality is directly proportionate to the lag time, amount of OP consumed, clinical severity, pseudo cholinesterase levels and duration of ventilator support. This study helps in rapid diagnosis, and rapid early and effective treatment, which may result in decreasing the morbidity and mortality rates. Recommendation: It is recommended to increase awareness regarding the rapid diagnosis, and rapid effective treatment of organ phosphorous.展开更多
A Convenient method for the synthesis of fused phosphorusheterocycle 1,3,2-oxazaphosphorin-[3.2-a]-8-oxo-10-thio(or seleno)-[1,3,2]-benzodiazaphosphorines was carried out in one pot by the reaction of Tris(diethylamin...A Convenient method for the synthesis of fused phosphorusheterocycle 1,3,2-oxazaphosphorin-[3.2-a]-8-oxo-10-thio(or seleno)-[1,3,2]-benzodiazaphosphorines was carried out in one pot by the reaction of Tris(diethylamino)phosphine with multifunctional compounds 2-(N-(beta or gamma-hydroxyl) alkylene) amino-benzamides 1. When PCL3 was used, only chlorinated product was obtained.展开更多
In normal phase condition, a series of chiral phosphorus organic compounds have been separated by high-performance liquid chromatography. In order to study the retention and chiral recognition mechanism, the method of...In normal phase condition, a series of chiral phosphorus organic compounds have been separated by high-performance liquid chromatography. In order to study the retention and chiral recognition mechanism, the method of quantitative structure-enantioselectivity retention relationships (QSERRs) has been investigated from the quantitative equations established between the chromatographic retention of enantiomers and their molecular descriptors of physicochemical properties. The results show that on the Pirkle-type chiral stationary phase (CSP) of Sumichiral OA4700, it is the parameter of LUMO that gives the most contribution to the chromatographic re-tention of O-ethyl O-(substituted) phenyl N-isopropyl phosphoroamidothioates resulting from the interaction of hydrogen bond and (or) p-p interaction. Meanwhile, the chiral recognition is formed from the contribution of logP and LUMO.展开更多
Ethyl((S)-2'-hydroxy-1,1'-binaphthalen-2-yl)-(SP)-vinylphosphonate (SBINOL-SP) was synthesized by diastereoselective reaction and characterized by means of NMR spectroscopy, H RMS and X-ray diffraction. The ...Ethyl((S)-2'-hydroxy-1,1'-binaphthalen-2-yl)-(SP)-vinylphosphonate (SBINOL-SP) was synthesized by diastereoselective reaction and characterized by means of NMR spectroscopy, H RMS and X-ray diffraction. The single crystal belongs to the monoclinic system, space group P21/c with a = 7.4983(13), b = 12.065(2), c = 21.805(4) ?, β = 90.094(6)°, Mr = 404.38, V = 1972.6(6) ?3, Z = 4, Dc = 1.362 g/cm3, F(000) = 848, μ = 0.168 mm-1, R = 0.0280 and wR = 0.0743. The title compound shows good activities against E. coli, S. albus, B. subtilis and M. tetragenus.展开更多
Stereodivergently constructing the designed products having adjacent multi-stereocenters via a given reaction,with excellent control of both absolute and relative configurations,presents one of the substantial hurdles...Stereodivergently constructing the designed products having adjacent multi-stereocenters via a given reaction,with excellent control of both absolute and relative configurations,presents one of the substantial hurdles in asymmetric catalysis.Herein,we report a precisely stereodivergent asymmetric protocol by synergistic combination of phosphonium-involved ion-pair catalysis and base for accessing to chiral phosphorus compounds bearing two adjacent chiral centers particularly containing an acidic protonated enantioenriched carbon atom,having broad functional group compatibility in both dynamic and thermodynamic processes under mild reaction conditions.Two keys for the success in constructing these stereoisomers with high levels of regio-,diastereo-,and enantioselectivities were contained:firstly,the precise stereo-control in providing dynamic products was enabled by bifunctional phosphonium salt catalyst with semi-enclosed cavity;secondly,the readily stereospecific transformation of adducts from dynamic to thermodynamic version was initiated by achiral base.All four stereoisomers could be readily accessed even in gram-scale in high yields with maintaining excellent stereoselectivities,illustrating the potential of this synergistic catalytic methodology in organic synthesis.Moreover,mechanistic studies including density functional theory(DFT)calculations and control experiments provide insights into the mechanism.展开更多
Ab initio LCAO-MO-SCF calculations for several typical molecules containing phosphorus have been undertaken to study the role of phosphorus 3d orbitals in the bonding.It is emphasized that the discussion about the 3d ...Ab initio LCAO-MO-SCF calculations for several typical molecules containing phosphorus have been undertaken to study the role of phosphorus 3d orbitals in the bonding.It is emphasized that the discussion about the 3d orbital participation in bonding should be based on a reasonable choice of basis sets and it seems suitable to choose the atomic orbitals in proper molecular environment as the basis set.As an approximation,the optimized minimal STO-NG basis sets have been adopted in the present paper.The results obtained well exhibit the model of 3d orbital participation in bonding. It is shown that under the influence of highly electronegative ligands the phosphorus 3d orbitals con- tract greatly,their energy levels drop considerably,and thus they can effectively participate in bond- ing.The presence of highly electronegative ligands seems necessary.The contribution of 3d orbitals to bonding is achieved mainly through the concertedformation of σ bonds and p-d backbonds,though the contribution to σ bonding is minor.The three-center,four-electron bond modelis only approxi- mately correct.The results of the present paper demonstrate that the model of 3d orbital participation in bonding favoured by experimental chemists is reasonable and possesses sound ground.展开更多
This work proposes a modified activated carbon support,with defects and heteroatoms(N,P-ACs)by nitrogen and phosphorus doping to load non-noble nickel to catalyze aromatic compound hydrogenation.The Ni/N,P-ACs-900(pre...This work proposes a modified activated carbon support,with defects and heteroatoms(N,P-ACs)by nitrogen and phosphorus doping to load non-noble nickel to catalyze aromatic compound hydrogenation.The Ni/N,P-ACs-900(prepared at 900℃)showed promising catalytic activity in liquid-phase 1,5-dinitronaphthalene hydrogenation with a 1,5-diaminonaphthalene yield of 95.8% under the mild condition of 100℃,which is comparable to the commercial Pd/C catalyst.The nitrogen species were burned off at 900℃,causing more defects for nickel metal loading,facilitating the interaction between the supports and the nickel metal,and resulting in highly dispersed metal particles.The computational study of the nickel binding energy has been conducted using density functional theory.It exhibits that the defects formed by heteroatom doping are beneficial to nickel anchoring and deposition to form highly uniform nickel particles.The phosphorus species in combination with the defects are suitable for H_(2) adsorption and dissociation.These results reveal that the heteroatomic doping on the active carbon shows significant effects in the hydrogenation of the liquid-phase aromatic compounds.These findings could provide a promising route for the rational design of aromatic compound hydrogenation catalysts to significantly decrease the cost by instead using noble metal catalysts in the industry.展开更多
Orthophosphate is an essential but limiting macronutrient for plant growth. About 67% cropland in China lacks sufficient phosphorus, especially that with red soil. Extensive soil phosphorus reserves exist in the form ...Orthophosphate is an essential but limiting macronutrient for plant growth. About 67% cropland in China lacks sufficient phosphorus, especially that with red soil. Extensive soil phosphorus reserves exist in the form of organic phosphorus, which is unavailable for root uptake unless hydrolyzed by secretory acid phosphatases. Thus, many microorganisms with the ability to produce phosphatase have been exploited. In this work, the activity of an extracellular acid phosphatase and yeast biomass from Candida mycoderma was measured under different culture conditions, such as pH, temperature, and carbon source. A maximal phosphatase activity of 8.47 × 10^5±0.11× 10^5 U/g was achieved by C. Mycoderma in 36 hr under the optimal conditions. The extracellular acid phosphatase has high activity over a wide pH tolerance range from 2.5 to S.0 (optimum pH 3.5). The effects of different phosphorus compounds on the acid phosphatase production were also studied. The presence of phytin, lecithin or calcium phosphate reduced the phosphatase activity and biomass yield significantly. In addition, the pH of the culture medium was reduced significantly by lecithin. The efficiency of the strain in releasing orthophosphate from organic phosphorus was studied in red soil (used in planting trees) and rice soil (originating as red soil). The available phosphorus content was increased by 230% after inoculating 20 days in rice soil and decreased by 50% after inoculating 10 days in red soil. This work indicates that the yeast strain C. mycoderma has potential application for enhancing phosphorus utilization in plants that grow in rice soil.展开更多
By studying the reaction of Co (acae)3; PPh3 and Al(C2H5)3 with CO2 in ether, we have obtained two kinds of crystals. One is dark red, which we call Crystal Ⅰ, with composition of CoH(CO)(PPh3)3(C2H5)2O; th...By studying the reaction of Co (acae)3; PPh3 and Al(C2H5)3 with CO2 in ether, we have obtained two kinds of crystals. One is dark red, which we call Crystal Ⅰ, with composition of CoH(CO)(PPh3)3(C2H5)2O; the other is orange red, which we call Crystal Ⅱ, with the composition of CoH(CO)(PPh3)3. Both are decomposed very rapidly in the air. Crystal Ⅰ is a little bit stabler than Crystal Ⅱ. We studied the structures of these two crystals by the X-ray diffraction method. There was a brief introduction about the structure of Crystal Ⅱ. This article will describe mainly the structure of Crystal Ⅰ. Some data of the structure of Crvstal展开更多
文摘A new method for generating reactive species to destroy toxic organic chemicals has been developed. This method reacts yellow phosphorus with O_2, in moist air to produce species such as O,O_3, PO, and PO_2, which are capable of reacting with various types of organics. Toxic organic com-pounds are converted to small molecular wight organic acids, aldehydes, and/or alcohols, while yel-low phosphonis is oxidital into phosphoric acid, which may be recovered as a valuable byproduct.This technique has ben demonstrated to be effective for destroying many types of toxic organiccompounds. including PAH, aromatic chlorides, amines, alcohols, and acids, nitro-aromatics,heterocyclic hydrocarbons, PCB, aliphatic chlorides and sulfides, dyes, and pesticides.
文摘2-methoxy-6-oxo-1, 4, 2-diazaphosphorinane-2-oxide 8, phosphorus counterpart of 2, 6-dioxopiperazine, was synthesized as antitumor agent. The new phosphorus heterocycle compound 8 is the key intermediate in the synthesis of phosphorus counterpart of bisdioxopiperazine.
文摘Using cation exchange resin(D72,Amberlyst-15) as catalyst, Mannich-type reaction of 5-amino-1,2,4-triazole 1, containing guanidine substructure, provides an efficient synthesis of a new kind of bicyclic P- and N-containing compounds, 6-phospha-4,5,6-trihydroimidazolo [2,3-e] 1,2,4-triazole 4.
基金National Basic Research Program of China (2009CB825101)Xinjiang Production and Construction Corps Technology Innovation Fund for Youth Project (2011CB02)+2 种基金National Natural Science Foundation of China (31000730)Chun Hui Project Item of Ministry of Education of China (Z2006-1-83023)Great Science and Technology Research Program of the Shihezi University (gxjs2012-zdgg06-02)
文摘Arbuscular mycorrhizal (AM) fungi penetrate the cortical cells of the roots of vascular plants, and are widely distributed in soil. The formation of these symbiotic bodies accelerates the absorption and utilization of min- eral elements, enhances plant resistance to stress, boosts the growth of plants, and increases the survival rate of transplanted seedlings. We studied the effects of various arbuscular mycorrhizae fungi on the growth and devel- opment of licorice (Glycyrrhiza glabra). Several species of AM, such as Glomus mosseae, Glomus intraradices, and a mixture of fungi (G. mosseae, G intraradices, G. cladoideum, G microagregatum, G caledonium and G. etunica- tum) were used in our study. Licorice growth rates were determined by measuring the colonization rate of the plants by the fungi, plant dry biomass, phosphorus concentration and concentration of secondary metabolites. We estab- lished two cloned strains of licorice, clone 3 (C3) and clone 6 (C6) to exclude the effect of genotypic variations. Our results showed that the AM fungi could in fact increase the leaf and root biomass, as well as the phosphorus con- centration in each clone. Furthermore, AM fungi significantly increased the yield of certain secondary metabolites in clone 3. Our study clearly demonstrated that AM fungi play an important role in the enhancement of growth and development of licorice plants. There was also a significant improvement in the secondary metabolite content and yield of medicinal compounds from the roots.
文摘Seventy organic compounds including various organophosphorus esters, amines and oxygen-based ligands were investigated as extractants. The experiment results show that amines are excellent extractants for W and Mo. Their sequence of extraction ability for W is as follows: quarternary amine > tertiary amine > secondary amine > primary amine. Acidic organophosphorus extractants do not extract W, but can extract Mo with high extraction ability from the acidic solution. These extractants could provide a potential process for separating W from Mo.
文摘An electron-addition, under single-crystal conditions, to pentavalent phosphorus compounds as Cl-P (=O, S) Y, Z with the P-Cl bond as electron-accepting group, is selected as an additional model for SN2(P) like reactions. It is demonstrated that the geometric information stored in the tetrahedral configuration (substrate) can be transmitted in the corresponding trigonal bipyramidal (TBP) state for nucleophilic substitution. In this article, we focus on these specific mechanistic aspects of carbon and phosphorus. We consider our study as a contribution to the significance of these (bio)chemical intermediates.
文摘The LPE growth of quaternary InAs11-x-yPxSby with x = 0.2 and y = 0.09 on InAs substrate has been studied. This composition is very suitable for the laser and detector applications at about 2.5 μm. We show that in InAsPSb/InAs system there is a determinate relation between the surface morphology and the lattice mismatch of the epi-wafers, by which we can easily control the melt composition to grow high quality hetero-structures. The reason has been discussed. The p-n junctions with fairly good carrier profile have been prepared in this system.
文摘Introduction: Organ phosphorus (OP) toxicity has been studied extensively because of its world wide use. Toxicity of organophosphates is the result of inhibition of acetyl cholinesterase resulting in cholinergic signs. Aim of the Work: To evaluate initial indicators that can indicate prognosis of patients in OP poisoning. Materials and Methods: A retrospective study conducted in Zagazig university hospital over a year. OP poisoning was clinically diagnosed with history of OP compound exposure and confirmed by low pseudo cholinesterase levels. Results: In the present study, 76 patients were enrolled. Major cases were male. High mortality rates were in the youth and in prolonged ventilated patients. The mortality rate was proportionally related to lag time after exposure and plasma pseudo cholinesterase levels. Electrolyte disturbance did not affect clinical outcome. Conclusion: From this study, it could be concluded that mortality is directly proportionate to the lag time, amount of OP consumed, clinical severity, pseudo cholinesterase levels and duration of ventilator support. This study helps in rapid diagnosis, and rapid early and effective treatment, which may result in decreasing the morbidity and mortality rates. Recommendation: It is recommended to increase awareness regarding the rapid diagnosis, and rapid effective treatment of organ phosphorous.
文摘A Convenient method for the synthesis of fused phosphorusheterocycle 1,3,2-oxazaphosphorin-[3.2-a]-8-oxo-10-thio(or seleno)-[1,3,2]-benzodiazaphosphorines was carried out in one pot by the reaction of Tris(diethylamino)phosphine with multifunctional compounds 2-(N-(beta or gamma-hydroxyl) alkylene) amino-benzamides 1. When PCL3 was used, only chlorinated product was obtained.
基金the Foundation for University Key Teacher by the Ministry of Education of China and Natural Science Foundation of Tianjin (Grant No. 983603311).
文摘In normal phase condition, a series of chiral phosphorus organic compounds have been separated by high-performance liquid chromatography. In order to study the retention and chiral recognition mechanism, the method of quantitative structure-enantioselectivity retention relationships (QSERRs) has been investigated from the quantitative equations established between the chromatographic retention of enantiomers and their molecular descriptors of physicochemical properties. The results show that on the Pirkle-type chiral stationary phase (CSP) of Sumichiral OA4700, it is the parameter of LUMO that gives the most contribution to the chromatographic re-tention of O-ethyl O-(substituted) phenyl N-isopropyl phosphoroamidothioates resulting from the interaction of hydrogen bond and (or) p-p interaction. Meanwhile, the chiral recognition is formed from the contribution of logP and LUMO.
文摘Ethyl((S)-2'-hydroxy-1,1'-binaphthalen-2-yl)-(SP)-vinylphosphonate (SBINOL-SP) was synthesized by diastereoselective reaction and characterized by means of NMR spectroscopy, H RMS and X-ray diffraction. The single crystal belongs to the monoclinic system, space group P21/c with a = 7.4983(13), b = 12.065(2), c = 21.805(4) ?, β = 90.094(6)°, Mr = 404.38, V = 1972.6(6) ?3, Z = 4, Dc = 1.362 g/cm3, F(000) = 848, μ = 0.168 mm-1, R = 0.0280 and wR = 0.0743. The title compound shows good activities against E. coli, S. albus, B. subtilis and M. tetragenus.
基金supported by the National Natural Science Foundation of China(21971165,21921002)the National Key R&D Program of China(2018YFA0903500)+3 种基金the“1000-Youth Talents Program”(YJ201702)the Fundamental Research Funds from Sichuan University(2020SCUNL108)Beijing National Laboratory for Molecular Sciences(BNLMS202101)the Fundamental Research Funds for the Central Universities。
文摘Stereodivergently constructing the designed products having adjacent multi-stereocenters via a given reaction,with excellent control of both absolute and relative configurations,presents one of the substantial hurdles in asymmetric catalysis.Herein,we report a precisely stereodivergent asymmetric protocol by synergistic combination of phosphonium-involved ion-pair catalysis and base for accessing to chiral phosphorus compounds bearing two adjacent chiral centers particularly containing an acidic protonated enantioenriched carbon atom,having broad functional group compatibility in both dynamic and thermodynamic processes under mild reaction conditions.Two keys for the success in constructing these stereoisomers with high levels of regio-,diastereo-,and enantioselectivities were contained:firstly,the precise stereo-control in providing dynamic products was enabled by bifunctional phosphonium salt catalyst with semi-enclosed cavity;secondly,the readily stereospecific transformation of adducts from dynamic to thermodynamic version was initiated by achiral base.All four stereoisomers could be readily accessed even in gram-scale in high yields with maintaining excellent stereoselectivities,illustrating the potential of this synergistic catalytic methodology in organic synthesis.Moreover,mechanistic studies including density functional theory(DFT)calculations and control experiments provide insights into the mechanism.
基金The National Natural Science Foundation of China.
文摘Ab initio LCAO-MO-SCF calculations for several typical molecules containing phosphorus have been undertaken to study the role of phosphorus 3d orbitals in the bonding.It is emphasized that the discussion about the 3d orbital participation in bonding should be based on a reasonable choice of basis sets and it seems suitable to choose the atomic orbitals in proper molecular environment as the basis set.As an approximation,the optimized minimal STO-NG basis sets have been adopted in the present paper.The results obtained well exhibit the model of 3d orbital participation in bonding. It is shown that under the influence of highly electronegative ligands the phosphorus 3d orbitals con- tract greatly,their energy levels drop considerably,and thus they can effectively participate in bond- ing.The presence of highly electronegative ligands seems necessary.The contribution of 3d orbitals to bonding is achieved mainly through the concertedformation of σ bonds and p-d backbonds,though the contribution to σ bonding is minor.The three-center,four-electron bond modelis only approxi- mately correct.The results of the present paper demonstrate that the model of 3d orbital participation in bonding favoured by experimental chemists is reasonable and possesses sound ground.
基金This work was supported by the National Natural Science Foundation of China(Grant No.21908185)Project of Hunan Provincial Natural Science Foundation of China(Grant No.2018JJ3497)+1 种基金Project of Hunan Provincial Education Department(Grant Nos.19B572 and 20B547)Collaborative Innovation Center of New Chemical Technologies for Environmental Benignity and Efficient Resource Utilization,and National Department of Education Engineering Research Centre for Chemical Process Simulation and Optimization.
文摘This work proposes a modified activated carbon support,with defects and heteroatoms(N,P-ACs)by nitrogen and phosphorus doping to load non-noble nickel to catalyze aromatic compound hydrogenation.The Ni/N,P-ACs-900(prepared at 900℃)showed promising catalytic activity in liquid-phase 1,5-dinitronaphthalene hydrogenation with a 1,5-diaminonaphthalene yield of 95.8% under the mild condition of 100℃,which is comparable to the commercial Pd/C catalyst.The nitrogen species were burned off at 900℃,causing more defects for nickel metal loading,facilitating the interaction between the supports and the nickel metal,and resulting in highly dispersed metal particles.The computational study of the nickel binding energy has been conducted using density functional theory.It exhibits that the defects formed by heteroatom doping are beneficial to nickel anchoring and deposition to form highly uniform nickel particles.The phosphorus species in combination with the defects are suitable for H_(2) adsorption and dissociation.These results reveal that the heteroatomic doping on the active carbon shows significant effects in the hydrogenation of the liquid-phase aromatic compounds.These findings could provide a promising route for the rational design of aromatic compound hydrogenation catalysts to significantly decrease the cost by instead using noble metal catalysts in the industry.
基金supported by a grant from the Special Project for Forest Public Benefit (No. 200904055)Project for Advantage Life Science of Jiangshu Province and Open Project of Jiangsu Key Laboratory for Biodiversity and Biotechnology (No. 164070302115)
文摘Orthophosphate is an essential but limiting macronutrient for plant growth. About 67% cropland in China lacks sufficient phosphorus, especially that with red soil. Extensive soil phosphorus reserves exist in the form of organic phosphorus, which is unavailable for root uptake unless hydrolyzed by secretory acid phosphatases. Thus, many microorganisms with the ability to produce phosphatase have been exploited. In this work, the activity of an extracellular acid phosphatase and yeast biomass from Candida mycoderma was measured under different culture conditions, such as pH, temperature, and carbon source. A maximal phosphatase activity of 8.47 × 10^5±0.11× 10^5 U/g was achieved by C. Mycoderma in 36 hr under the optimal conditions. The extracellular acid phosphatase has high activity over a wide pH tolerance range from 2.5 to S.0 (optimum pH 3.5). The effects of different phosphorus compounds on the acid phosphatase production were also studied. The presence of phytin, lecithin or calcium phosphate reduced the phosphatase activity and biomass yield significantly. In addition, the pH of the culture medium was reduced significantly by lecithin. The efficiency of the strain in releasing orthophosphate from organic phosphorus was studied in red soil (used in planting trees) and rice soil (originating as red soil). The available phosphorus content was increased by 230% after inoculating 20 days in rice soil and decreased by 50% after inoculating 10 days in red soil. This work indicates that the yeast strain C. mycoderma has potential application for enhancing phosphorus utilization in plants that grow in rice soil.
文摘By studying the reaction of Co (acae)3; PPh3 and Al(C2H5)3 with CO2 in ether, we have obtained two kinds of crystals. One is dark red, which we call Crystal Ⅰ, with composition of CoH(CO)(PPh3)3(C2H5)2O; the other is orange red, which we call Crystal Ⅱ, with the composition of CoH(CO)(PPh3)3. Both are decomposed very rapidly in the air. Crystal Ⅰ is a little bit stabler than Crystal Ⅱ. We studied the structures of these two crystals by the X-ray diffraction method. There was a brief introduction about the structure of Crystal Ⅱ. This article will describe mainly the structure of Crystal Ⅰ. Some data of the structure of Crvstal