Langmuir films behavior of asymmetric glycerol dialkyl nonitol tetraether (GDNT) lipids at the air-water interface (temperature 19℃ ± 1℃) investigated the stability of the mean ratio of Langmuir films for diffe...Langmuir films behavior of asymmetric glycerol dialkyl nonitol tetraether (GDNT) lipids at the air-water interface (temperature 19℃ ± 1℃) investigated the stability of the mean ratio of Langmuir films for different spreading time prior to the transfer film. Floating monolayer films stability is an important parameter to obtain high-quality Langmuir-Blodgett films for their aplications. Hysteresis loop of the compression-decompression (μ-A) isotherms of Langmuir film GDNT used to analyze the thermodynamic stability of the monolayer films and its features. Langmuir films stability of tetraether lipid GDNT shown more stable at the time of spreading longer than a short time.展开更多
A new complexes of Cp2Ti[S2P(OR)2]2 (where R = Et, Pr-n, Pr-i, Bu-i and Ph) and Cp2Ti[S2POGO]2 (where G = -CH2CMe2CH2-, -CH2CEt2CH2- and -CMe2CMe2-) were prepared by the dropwise addition of the appropriate O,O’-dial...A new complexes of Cp2Ti[S2P(OR)2]2 (where R = Et, Pr-n, Pr-i, Bu-i and Ph) and Cp2Ti[S2POGO]2 (where G = -CH2CMe2CH2-, -CH2CEt2CH2- and -CMe2CMe2-) were prepared by the dropwise addition of the appropriate O,O’-dialkyl or -alkylenedithiophosphoric acid to biscyclopentadienyl titanium dichloride in 1:2 molar ratio and refluxed in benzene solution. These novel deep red colored complexes were characterized by elemental analyses, molecular weight measurements and spectroscopic techniques (IR., NMR 1H, 13C and 31P NMR). These titanium (IV) dithio complexes have also been screened for their antibacterial activities.展开更多
A novel series of para-diiodobenzene derivatives, 3,6-diiodo-4,5-dialkyl-phthalic acid dimethyl esters, were prepared via cycloaddition of two TMS-substituted alkynes and dimethyl acetylenedicarboxylate, which was med...A novel series of para-diiodobenzene derivatives, 3,6-diiodo-4,5-dialkyl-phthalic acid dimethyl esters, were prepared via cycloaddition of two TMS-substituted alkynes and dimethyl acetylenedicarboxylate, which was mediated by zirconocene. After iodination, three new compounds of 3,6-diiodo-4,5-dimethyl(dipropyl, dibutyl)-phthalic acid dimethyl esters (3a, 3b, 3c) were synthesized in high region-selectivity and yields, and characterized by NMR. The crystal structures were determined by single-crystal X-ray diffraction. The crystal of 3a (C12H121204, Mr = 474.02) belongs to the triclinic system, space group Pi with a = 7.6238(10), b = 9.4571(12), c = 10.8221(14) A, a = 66.611(10), fl = 88.511(12), 7 : 77.604(11)% V= 697.93(16) A3, Z= 2, F(000) = 444, Dc = 2.256 mg/m3, g = 4.509 mm-1, T=133(2) K, S = 1.014, R = 0.0229 and wR = 0.0547 for 2644 observed reflections with I 〉 20(/); the crystal of 3b (C16H201204, Mr - 530.12) is of triclinic system, space group Pi with a = 9.4122(19), b = 10.626(2), c = 11.353(2) A, a = 97.90(3), fl = 113.83(3), y = 110.22(3)°, V= 922.6(3) A3, Z- 2, F(000) = 508, Dc - 1.908 mg/m3, g = 3.422 mm-1, T = 113(2) K, S = 1.115, R = 0.0428 and wR = 0.1072 for 3971 observed reflections with I〉 20(/); the crystal of 3c (ClsH241204, Mr = 558.17) belongs to the monoclinic system, space group P21/c with a = 26.396(2), b = 8.7560(8), c = 25.7970(18) A, fl = 91.721(4)o, V= 5959.6(8) A3, Z = 12, F(000) = 3240, Dc = 1.866 mg/m3,/z = 3.184 mm-l, T= 113(2) K, S = 1.154, R = 0.0424 and wR = 0.0766 for 13056 observed reflections with I 〉 20(/).展开更多
A series of new complexes, CpTiCl[S2P(OR)2]2 (where R) Et, n-Pr, i-Pr, Bui, Ph) and CpTiCl [S2POGO]2 (where G) –CH2CMe2CH2-, -CMe2CMe2-) have been prepared by the drop wise addition of the appropriate O, O’-dialkyl ...A series of new complexes, CpTiCl[S2P(OR)2]2 (where R) Et, n-Pr, i-Pr, Bui, Ph) and CpTiCl [S2POGO]2 (where G) –CH2CMe2CH2-, -CMe2CMe2-) have been prepared by the drop wise addition of the appropriate O, O’-dialkyl or -alkylene dithiophosphoric acid to cyclopentadienyl titanium trichloride in 1:2 molar ratio and refluxed in benzene solution. The new compounds were characterized by molecular weight measurements elemental analyses and spectroscopic studies (1H, 13C, and 31P NMR, and in-frared). We suggest a distorted tetrahedron structure of these new complexes and the dithioligand behaves as bidentate ligand.展开更多
4,4-Dialkyl-2-oxazolin-5-ones are prepared by one step reaction of 2-oxazolin-5-one with the magnesium methyl carbonate(MMC)and alkyIhalides.It is a novel and convenient method for synthesis of α, Υ-disubstitutcd α...4,4-Dialkyl-2-oxazolin-5-ones are prepared by one step reaction of 2-oxazolin-5-one with the magnesium methyl carbonate(MMC)and alkyIhalides.It is a novel and convenient method for synthesis of α, Υ-disubstitutcd α-amino acid by hydrolysis of 4,4-dialkyl-2-oxazolin-5-ones.展开更多
Dialkyl-substituted terminal olefins were synthesized from the coupling reaction of a-olefins which were catalyzed by zirconocene dichloride/methylalumoxane (MAO) catalyst system under mild condition. High yield was...Dialkyl-substituted terminal olefins were synthesized from the coupling reaction of a-olefins which were catalyzed by zirconocene dichloride/methylalumoxane (MAO) catalyst system under mild condition. High yield was gained and no other oligmer was detected. It was found that the ratio of AI/Zr is responsible for the selectivity of product.展开更多
In this paper, chiral discrimination in N-(O,O-dialkyl)phosphoamino acid monolayers at the air/water interface was studied and it was revealed that the D:L=1:1 racemic monolayer of N-(O, O-dihexadecyl)phosphoalanine i...In this paper, chiral discrimination in N-(O,O-dialkyl)phosphoamino acid monolayers at the air/water interface was studied and it was revealed that the D:L=1:1 racemic monolayer of N-(O, O-dihexadecyl)phosphoalanine is packed more densely in solid phase while shows a higher LE to LC transition pressure than the enantiomeric ones.展开更多
Eight dialkyl tetrabromophthalates (DATBPs) were synthesized by reacting tetrabromophthalic anhydride with excess alcohols which were used not only as a reactant but also as a solvent and using a quaternary ammonium s...Eight dialkyl tetrabromophthalates (DATBPs) were synthesized by reacting tetrabromophthalic anhydride with excess alcohols which were used not only as a reactant but also as a solvent and using a quaternary ammonium salt as a phase transfer catalyst (PTC). The yields were found to be between 85-93%. Their structures were characterized by IR, NMR and elementary analysis. The flame retardant properties of the compounds were also studied.展开更多
1-Isocyano substituted benzylphosphonates were prepared by dehydration of 1-N-formylamino substituted benzylphosphonates,which were obtained by a tricomponental condensation described by us.Mean- while addition of die...1-Isocyano substituted benzylphosphonates were prepared by dehydration of 1-N-formylamino substituted benzylphosphonates,which were obtained by a tricomponental condensation described by us.Mean- while addition of diethyl phosphite to N-trityl aldimine followed by deprotection,formylation and dehydration gave corresponding 1-isocyano alkylphosphonates in one-pot procedure.展开更多
We investigated the occurrence and distribution of terrestrial-derived hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers(OH-GDGTs) in the Han River system and their potential impact on the application of t...We investigated the occurrence and distribution of terrestrial-derived hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers(OH-GDGTs) in the Han River system and their potential impact on the application of the ring index of OH-GDGTs(RI-OH) as a sea surface temperature(SST) proxy in the eastern Yellow Sea. Thereby, we analyzed various samples collected along the Han River and from its surrounding areas(South Korea, n = 34). The OHGDGTs were found in all samples investigated. OH-GDGT-0 was the dominant OH-GDGT component in the estuary and marine samples while OH-GDGT-2 was generally dominant in the soils, the lake sediments and the river suspended particulate matter(SPM). Our results thus suggests a possible warm bias of the RI-OH-derived summer SSTs in the coastal zone to which a large amount of terrestrial organic matter is being supplied. Further studies are necessary to better assess the applicability of the RI-OH proxy in the eastern Yellow Sea.展开更多
We applied the technique of mRNA differential display to normal liver tissue and hepatoma cell line Hep3B. One of the isolated cDNA clones was expressed in human normal liver tissue but not in the human hepatocarcinom...We applied the technique of mRNA differential display to normal liver tissue and hepatoma cell line Hep3B. One of the isolated cDNA clones was expressed in human normal liver tissue but not in the human hepatocarcinoma cell line. Northern Blot analysis confirmed that high level of mRNA was expressed in human normal liver tissue but the level was decreased in non-cancerous liver tissue from hepatoma patients. Low level or no expression was observed in human hepatoma tissue. One of these transcripts was about 1.8 kb in length. Southern Blot analysis showed that it was a single copy gene. We obtained a full length cDNA clone of 2,395 bp by screening human liver 5’-stretch plus cDNA library. Nucleotide sequence indicated that this clone was highly homologous to aryldialkyl-phosphatase and possessed two polymorphic sites. Aryl-dialkyl--phosphatase which has a prominent role in the metabolism of several toxic, synthetic compounds, may be potentially related to human hepatocarcinoma susceptibility. The biological significance of its differential expression in normal versus malignant tissue is discussed.展开更多
Asymmetric hydrogenation of dialkyl imines to chiral amines is difficult because the two alkyls of imines are so similar in spatial and electronic structure that chiral catalysts are difficult to distinguish between t...Asymmetric hydrogenation of dialkyl imines to chiral amines is difficult because the two alkyls of imines are so similar in spatial and electronic structure that chiral catalysts are difficult to distinguish between them.In this study,we described an asymmetric hydrogenation of dialkyl imines by a chiral iridium catalyst containing spiro phosphine-amine-phosphine ligand.By precisely adjusting the chiral pocket of catalyst,a highly efficient catalyst was developed.Using this catalyst,a variety of dialkyl imines were hydrogenated to chiral amines with high yield and enantioselectivity.展开更多
An efficient multicomponent reaction of 3-indolyl-3-oxopropanenitriles with dialkyl acetylenedicarboxylates and isocyanides under mild conditions leading to highly functionalized 6-(indol-3-yl)-4H-pyrans in moderate t...An efficient multicomponent reaction of 3-indolyl-3-oxopropanenitriles with dialkyl acetylenedicarboxylates and isocyanides under mild conditions leading to highly functionalized 6-(indol-3-yl)-4H-pyrans in moderate to good yields has been developed.展开更多
Rare-earth metal dialkyl complexes[1-Bn-3-(DippN=CH)C_(8)H_(4)N]RE(CH_(2)SiMe_(3))2(thf)2(Dipp=2,6-iPr_(2)C_(6)H_(3),RE=Y(1)and Er(2))were prepared through the cyclometalation reactions of the N-Bn-3-imino-functionali...Rare-earth metal dialkyl complexes[1-Bn-3-(DippN=CH)C_(8)H_(4)N]RE(CH_(2)SiMe_(3))2(thf)2(Dipp=2,6-iPr_(2)C_(6)H_(3),RE=Y(1)and Er(2))were prepared through the cyclometalation reactions of the N-Bn-3-imino-functionalized indolyl ligand 1-Bn-3-(DippN=CH)C8H5N with one equivalent of rare-earth metal trialkyl precursors.The structures of compounds 1 and 2 were confirmed by X-ray crystal analyses and characterized by elemental analysis,IR,NMR spectroscopy wherein applicable.In the presence of cocatalysts,these rare-earth metal dialkyl complexes initiated isoprene polymerization with a high activity(95% conversion of 2000 equivalent of isoprene in 360 min),producing polymers with high regioselectivity(1,4-polymers up to 91%).展开更多
文摘Langmuir films behavior of asymmetric glycerol dialkyl nonitol tetraether (GDNT) lipids at the air-water interface (temperature 19℃ ± 1℃) investigated the stability of the mean ratio of Langmuir films for different spreading time prior to the transfer film. Floating monolayer films stability is an important parameter to obtain high-quality Langmuir-Blodgett films for their aplications. Hysteresis loop of the compression-decompression (μ-A) isotherms of Langmuir film GDNT used to analyze the thermodynamic stability of the monolayer films and its features. Langmuir films stability of tetraether lipid GDNT shown more stable at the time of spreading longer than a short time.
文摘A new complexes of Cp2Ti[S2P(OR)2]2 (where R = Et, Pr-n, Pr-i, Bu-i and Ph) and Cp2Ti[S2POGO]2 (where G = -CH2CMe2CH2-, -CH2CEt2CH2- and -CMe2CMe2-) were prepared by the dropwise addition of the appropriate O,O’-dialkyl or -alkylenedithiophosphoric acid to biscyclopentadienyl titanium dichloride in 1:2 molar ratio and refluxed in benzene solution. These novel deep red colored complexes were characterized by elemental analyses, molecular weight measurements and spectroscopic techniques (IR., NMR 1H, 13C and 31P NMR). These titanium (IV) dithio complexes have also been screened for their antibacterial activities.
文摘A novel series of para-diiodobenzene derivatives, 3,6-diiodo-4,5-dialkyl-phthalic acid dimethyl esters, were prepared via cycloaddition of two TMS-substituted alkynes and dimethyl acetylenedicarboxylate, which was mediated by zirconocene. After iodination, three new compounds of 3,6-diiodo-4,5-dimethyl(dipropyl, dibutyl)-phthalic acid dimethyl esters (3a, 3b, 3c) were synthesized in high region-selectivity and yields, and characterized by NMR. The crystal structures were determined by single-crystal X-ray diffraction. The crystal of 3a (C12H121204, Mr = 474.02) belongs to the triclinic system, space group Pi with a = 7.6238(10), b = 9.4571(12), c = 10.8221(14) A, a = 66.611(10), fl = 88.511(12), 7 : 77.604(11)% V= 697.93(16) A3, Z= 2, F(000) = 444, Dc = 2.256 mg/m3, g = 4.509 mm-1, T=133(2) K, S = 1.014, R = 0.0229 and wR = 0.0547 for 2644 observed reflections with I 〉 20(/); the crystal of 3b (C16H201204, Mr - 530.12) is of triclinic system, space group Pi with a = 9.4122(19), b = 10.626(2), c = 11.353(2) A, a = 97.90(3), fl = 113.83(3), y = 110.22(3)°, V= 922.6(3) A3, Z- 2, F(000) = 508, Dc - 1.908 mg/m3, g = 3.422 mm-1, T = 113(2) K, S = 1.115, R = 0.0428 and wR = 0.1072 for 3971 observed reflections with I〉 20(/); the crystal of 3c (ClsH241204, Mr = 558.17) belongs to the monoclinic system, space group P21/c with a = 26.396(2), b = 8.7560(8), c = 25.7970(18) A, fl = 91.721(4)o, V= 5959.6(8) A3, Z = 12, F(000) = 3240, Dc = 1.866 mg/m3,/z = 3.184 mm-l, T= 113(2) K, S = 1.154, R = 0.0424 and wR = 0.0766 for 13056 observed reflections with I 〉 20(/).
文摘A series of new complexes, CpTiCl[S2P(OR)2]2 (where R) Et, n-Pr, i-Pr, Bui, Ph) and CpTiCl [S2POGO]2 (where G) –CH2CMe2CH2-, -CMe2CMe2-) have been prepared by the drop wise addition of the appropriate O, O’-dialkyl or -alkylene dithiophosphoric acid to cyclopentadienyl titanium trichloride in 1:2 molar ratio and refluxed in benzene solution. The new compounds were characterized by molecular weight measurements elemental analyses and spectroscopic studies (1H, 13C, and 31P NMR, and in-frared). We suggest a distorted tetrahedron structure of these new complexes and the dithioligand behaves as bidentate ligand.
文摘4,4-Dialkyl-2-oxazolin-5-ones are prepared by one step reaction of 2-oxazolin-5-one with the magnesium methyl carbonate(MMC)and alkyIhalides.It is a novel and convenient method for synthesis of α, Υ-disubstitutcd α-amino acid by hydrolysis of 4,4-dialkyl-2-oxazolin-5-ones.
文摘Dialkyl-substituted terminal olefins were synthesized from the coupling reaction of a-olefins which were catalyzed by zirconocene dichloride/methylalumoxane (MAO) catalyst system under mild condition. High yield was gained and no other oligmer was detected. It was found that the ratio of AI/Zr is responsible for the selectivity of product.
文摘In this paper, chiral discrimination in N-(O,O-dialkyl)phosphoamino acid monolayers at the air/water interface was studied and it was revealed that the D:L=1:1 racemic monolayer of N-(O, O-dihexadecyl)phosphoalanine is packed more densely in solid phase while shows a higher LE to LC transition pressure than the enantiomeric ones.
文摘Eight dialkyl tetrabromophthalates (DATBPs) were synthesized by reacting tetrabromophthalic anhydride with excess alcohols which were used not only as a reactant but also as a solvent and using a quaternary ammonium salt as a phase transfer catalyst (PTC). The yields were found to be between 85-93%. Their structures were characterized by IR, NMR and elementary analysis. The flame retardant properties of the compounds were also studied.
文摘1-Isocyano substituted benzylphosphonates were prepared by dehydration of 1-N-formylamino substituted benzylphosphonates,which were obtained by a tricomponental condensation described by us.Mean- while addition of diethyl phosphite to N-trityl aldimine followed by deprotection,formylation and dehydration gave corresponding 1-isocyano alkylphosphonates in one-pot procedure.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIP)(No.NRF-2016R1A2B3015388)
文摘We investigated the occurrence and distribution of terrestrial-derived hydroxylated isoprenoid glycerol dialkyl glycerol tetraethers(OH-GDGTs) in the Han River system and their potential impact on the application of the ring index of OH-GDGTs(RI-OH) as a sea surface temperature(SST) proxy in the eastern Yellow Sea. Thereby, we analyzed various samples collected along the Han River and from its surrounding areas(South Korea, n = 34). The OHGDGTs were found in all samples investigated. OH-GDGT-0 was the dominant OH-GDGT component in the estuary and marine samples while OH-GDGT-2 was generally dominant in the soils, the lake sediments and the river suspended particulate matter(SPM). Our results thus suggests a possible warm bias of the RI-OH-derived summer SSTs in the coastal zone to which a large amount of terrestrial organic matter is being supplied. Further studies are necessary to better assess the applicability of the RI-OH proxy in the eastern Yellow Sea.
基金supported by the National Natural Science Foundation of China(Grant No.40972211)the US National Science Foundation(Grant Nos.ETBC-1024614 and OISE- 0968421 )
基金the National Basic Research Program of China 973 Program(No.2003CB114400)the National Natural Science Foundation of China(No.20476098)for financial support.(No.20676123)
文摘We applied the technique of mRNA differential display to normal liver tissue and hepatoma cell line Hep3B. One of the isolated cDNA clones was expressed in human normal liver tissue but not in the human hepatocarcinoma cell line. Northern Blot analysis confirmed that high level of mRNA was expressed in human normal liver tissue but the level was decreased in non-cancerous liver tissue from hepatoma patients. Low level or no expression was observed in human hepatoma tissue. One of these transcripts was about 1.8 kb in length. Southern Blot analysis showed that it was a single copy gene. We obtained a full length cDNA clone of 2,395 bp by screening human liver 5’-stretch plus cDNA library. Nucleotide sequence indicated that this clone was highly homologous to aryldialkyl-phosphatase and possessed two polymorphic sites. Aryl-dialkyl--phosphatase which has a prominent role in the metabolism of several toxic, synthetic compounds, may be potentially related to human hepatocarcinoma susceptibility. The biological significance of its differential expression in normal versus malignant tissue is discussed.
基金supported by the National Key R&D Program of China(grant no.2022YFA1504302)the National Natural Science Foundation of China(grant nos.22188101,91956000,and 92256301)the Fundamental Research Funds for the Central Universities,and the Haihe Laboratory of Sustainable Chemical Transformations.
文摘Asymmetric hydrogenation of dialkyl imines to chiral amines is difficult because the two alkyls of imines are so similar in spatial and electronic structure that chiral catalysts are difficult to distinguish between them.In this study,we described an asymmetric hydrogenation of dialkyl imines by a chiral iridium catalyst containing spiro phosphine-amine-phosphine ligand.By precisely adjusting the chiral pocket of catalyst,a highly efficient catalyst was developed.Using this catalyst,a variety of dialkyl imines were hydrogenated to chiral amines with high yield and enantioselectivity.
基金We gratefully acknowledge the National Natural Science Foundation of China(Nos.21172162,21372174)the Ph.D.Programs Foundation of Ministry of Education of China(No.2013201130004),the Scientific Research Foundation for the Returned Overseas Chinese Scholars,PAPD,and Soochow University for financial support.
文摘An efficient multicomponent reaction of 3-indolyl-3-oxopropanenitriles with dialkyl acetylenedicarboxylates and isocyanides under mild conditions leading to highly functionalized 6-(indol-3-yl)-4H-pyrans in moderate to good yields has been developed.
基金supported by the Natural Science Foundation of Anhui Province(No.2008085ME174)financial support from Anhui Normal University(FMS201915)。
文摘Rare-earth metal dialkyl complexes[1-Bn-3-(DippN=CH)C_(8)H_(4)N]RE(CH_(2)SiMe_(3))2(thf)2(Dipp=2,6-iPr_(2)C_(6)H_(3),RE=Y(1)and Er(2))were prepared through the cyclometalation reactions of the N-Bn-3-imino-functionalized indolyl ligand 1-Bn-3-(DippN=CH)C8H5N with one equivalent of rare-earth metal trialkyl precursors.The structures of compounds 1 and 2 were confirmed by X-ray crystal analyses and characterized by elemental analysis,IR,NMR spectroscopy wherein applicable.In the presence of cocatalysts,these rare-earth metal dialkyl complexes initiated isoprene polymerization with a high activity(95% conversion of 2000 equivalent of isoprene in 360 min),producing polymers with high regioselectivity(1,4-polymers up to 91%).