Two coordination polymers called [Ni(L)2]n(1) and [Ni(2,2?-bpy)22(H2O)]n (2)(HL = 4-benzoimidazol-1-yl-methyl benzoic acid, 2,2?-bpy = 2,2'-dipyridine) were synthesized by solvothermal reaction simultan...Two coordination polymers called [Ni(L)2]n(1) and [Ni(2,2?-bpy)22(H2O)]n (2)(HL = 4-benzoimidazol-1-yl-methyl benzoic acid, 2,2?-bpy = 2,2'-dipyridine) were synthesized by solvothermal reaction simultaneously and characterized by elemental analyses, thermogravimetric analysis, X-ray powder diffraction, IR spectroscopy and single-crystal X-ray diffraction analysis. Complex 1 crystallizes in monoclinic system, space group P21/c with a = 14.673(3), b = 10.773(2), c = 16.566(3) ?, V = 2559.2(8) A^3, Z = 4 and F(000) = 1160. 2 also crystallizes in monoclinic system, space group C2/c with a = 15.404(3), b = 12.652(3), c = 6.5362(13) ?, V = 1246.2(5) A^3, Z = 4 and F(000) = 712. The bridging L ligand connects the Ni^Ⅱ cations into a 2D network in complex 1, while 2 shows a 1D structure formed through the two O atoms of SO4^(2-) ions connecting the molecule. The catalytic properties indicate that complex 1 shows good catalytic activities for the cyanosilylation of 4-chlorobenzaldehyde. In addition, fluorescence property of complex 1 which quenches the excitation intensity in solid state was investigated at room temperature.展开更多
The CO_2 quenching method has been used for the first time to determine the active complex concen- tration in Nd(naph)_3-Al(i-Bu)_3 catalyst system for polymerization of phenylacetylene into polyphenylacetylene(PPA)fi...The CO_2 quenching method has been used for the first time to determine the active complex concen- tration in Nd(naph)_3-Al(i-Bu)_3 catalyst system for polymerization of phenylacetylene into polyphenylacetylene(PPA)films.The kinetics and mechanism of this polymerization have been investigated by CO_2 quenching and IR,UV analytical methods.The kinetic equation can be expressed as Rp=k[M][Cp],and the apparent activation energy is about 13.6 kJ/mol.There is self-termination of chain propagating.Models for formation of the active complex and polymerization mechanism are proposed.展开更多
In this paper, the stereoselective homogeneous catalysis polymerization of phenylacetylene by using two kinds of catalysts W(CO)_5CH_3I and W(CO)_4I_2 produced from UV laser photolysis of W (CO)_6 in CH_3I, I_2—C_6H_...In this paper, the stereoselective homogeneous catalysis polymerization of phenylacetylene by using two kinds of catalysts W(CO)_5CH_3I and W(CO)_4I_2 produced from UV laser photolysis of W (CO)_6 in CH_3I, I_2—C_6H_6 and CHI_3—C_6H_6 respectively was studied. The effects of laser energy, laser irradiation time and lifetime of catalyst on the polymerization of phenylacetylene were discussed. The photoproducts of W (CO)_6 in CH_3I, I2—C_6H_6 and CHI_3—C_6I_6 were determined by IR spectra. The structures of polyphenylacetylene obtained by W (CO)_5CH_3I and W (CO)_4I_2 catalysts were characterized by IR spectra and ~1H NMR spectra.展开更多
Complexes of lanthanide trisborohydrides, formally Ln(BH4)3(THF), (Ln=La, Ce, Sm, Yb), were synthesized and their catalytic activity for polymerization of ε-caprolactone was studied. All the complexes can catal...Complexes of lanthanide trisborohydrides, formally Ln(BH4)3(THF), (Ln=La, Ce, Sm, Yb), were synthesized and their catalytic activity for polymerization of ε-caprolactone was studied. All the complexes can catalyze this polymerization. It was found that the catalytic activities decreased in the order of La〉Ce〉Sm〉Yb. The crystal structure of cerium trisborohydride was determined for the first time by single crystal X-ray diffraction analysis. It is an ionic pair complex of [Ce(BH4)E(THF)5][Ce(BH4)4(THF)2]. The cationic part involves two ηa-BH4 ligands, while the anionic part involves two η3-BH4 groups and two η2-BH4 groups.展开更多
Transition metal-mediated atom transfer radical polymerization (ATRP) is a "living"Jcontrolled radical polymerization. Recently, there has been widely increasing interest in reducing the high costs of catalyst sep...Transition metal-mediated atom transfer radical polymerization (ATRP) is a "living"Jcontrolled radical polymerization. Recently, there has been widely increasing interest in reducing the high costs of catalyst separation and post-polymerization purification in ATRP. In this work, trolamine was found to significantly enhance the catalytical performance of CuBr]N,N,N',N'-tetrakis(2-pyridylmethyl) ethyle- nediamine (CuBr/TPEN) and CuBr/tris[2-(dimethylamino) ethylamine] (CuBr/MesTREN). With the addition of 25-fold molar amount of trolamine relative to CuBr, the catalyst loadings of CuBr/TPEN and CuBr/Me6TREN were dramatically reduced from a catalyst-to-initiator ratio of 1 to 0.01 and 0.05, respectively. The polymerizations of methyl acrylate, methyl methacrylate and styrene still showed first-order kinetics in the presence of trolamine and produced poly(methyl acrylate), poly(methyl methacrylate) and polystyrene with molecular weights close to theoretical values and low polydispersities. These results indicate that trolamine is a highly effective and versatile promoter for ATRP and is promising for potential industrial application.展开更多
Owing to its high production volume and wide range of application s,polyethylene has gained a great deal of attention,but its low surface energy and non-polar nature have limited its application in some important fiel...Owing to its high production volume and wide range of application s,polyethylene has gained a great deal of attention,but its low surface energy and non-polar nature have limited its application in some important fields.In this study,ethylene/11-iodo-1-undecene copolymers were prepared and used as the intermediates to afford a series of imidazolium-based ionomers bearing methanesulfonate(CH_(3)SO_(3)^(-)),trifluoromethanesulfonate(CF_(3)SO_(3)^(-)),or bis(trifluoromethane)sulfonimide(Tf_(2)N^(-))counteranions.The tensile test results showed that the stress-at-break(7.8-25.6 MPa)and the elongation-at-break(445%-847%)of the ionomers could be adjusted by changing the counterion species and the ionic group contents.Most importantly,the ionomers exhibited marvelous antibacterial activities against Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).The ionomers bearing Tf_(2)N^(-)exhibited antibacterial activities>99%against both S.aureus and E.coli when ionic content reached 9.1%.The imidazolium-based ionomers prepared in this work demonstrated excellent comprehensive properties,especially highefficient and broad-spectrum antibacterial ability,exhibiting the potential fo r the application as the antibacterial materials in packaging,medical,and other fields.展开更多
基金supported by the National Natural Science Foundation of China(21171075/B010303,21103073/B030201,21306067/B060903)Innovation&Entrepreneurship Traning Program of China(201410299054Y)
文摘Two coordination polymers called [Ni(L)2]n(1) and [Ni(2,2?-bpy)22(H2O)]n (2)(HL = 4-benzoimidazol-1-yl-methyl benzoic acid, 2,2?-bpy = 2,2'-dipyridine) were synthesized by solvothermal reaction simultaneously and characterized by elemental analyses, thermogravimetric analysis, X-ray powder diffraction, IR spectroscopy and single-crystal X-ray diffraction analysis. Complex 1 crystallizes in monoclinic system, space group P21/c with a = 14.673(3), b = 10.773(2), c = 16.566(3) ?, V = 2559.2(8) A^3, Z = 4 and F(000) = 1160. 2 also crystallizes in monoclinic system, space group C2/c with a = 15.404(3), b = 12.652(3), c = 6.5362(13) ?, V = 1246.2(5) A^3, Z = 4 and F(000) = 712. The bridging L ligand connects the Ni^Ⅱ cations into a 2D network in complex 1, while 2 shows a 1D structure formed through the two O atoms of SO4^(2-) ions connecting the molecule. The catalytic properties indicate that complex 1 shows good catalytic activities for the cyanosilylation of 4-chlorobenzaldehyde. In addition, fluorescence property of complex 1 which quenches the excitation intensity in solid state was investigated at room temperature.
文摘The CO_2 quenching method has been used for the first time to determine the active complex concen- tration in Nd(naph)_3-Al(i-Bu)_3 catalyst system for polymerization of phenylacetylene into polyphenylacetylene(PPA)films.The kinetics and mechanism of this polymerization have been investigated by CO_2 quenching and IR,UV analytical methods.The kinetic equation can be expressed as Rp=k[M][Cp],and the apparent activation energy is about 13.6 kJ/mol.There is self-termination of chain propagating.Models for formation of the active complex and polymerization mechanism are proposed.
文摘In this paper, the stereoselective homogeneous catalysis polymerization of phenylacetylene by using two kinds of catalysts W(CO)_5CH_3I and W(CO)_4I_2 produced from UV laser photolysis of W (CO)_6 in CH_3I, I_2—C_6H_6 and CHI_3—C_6H_6 respectively was studied. The effects of laser energy, laser irradiation time and lifetime of catalyst on the polymerization of phenylacetylene were discussed. The photoproducts of W (CO)_6 in CH_3I, I2—C_6H_6 and CHI_3—C_6I_6 were determined by IR spectra. The structures of polyphenylacetylene obtained by W (CO)_5CH_3I and W (CO)_4I_2 catalysts were characterized by IR spectra and ~1H NMR spectra.
基金Project supported by Jiangsu Key Laboratory for the Environment Functional Materialsthe Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Innovation Program for Graduate Students of USTS(SKCX11S-058)
文摘Complexes of lanthanide trisborohydrides, formally Ln(BH4)3(THF), (Ln=La, Ce, Sm, Yb), were synthesized and their catalytic activity for polymerization of ε-caprolactone was studied. All the complexes can catalyze this polymerization. It was found that the catalytic activities decreased in the order of La〉Ce〉Sm〉Yb. The crystal structure of cerium trisborohydride was determined for the first time by single crystal X-ray diffraction analysis. It is an ionic pair complex of [Ce(BH4)E(THF)5][Ce(BH4)4(THF)2]. The cationic part involves two ηa-BH4 ligands, while the anionic part involves two η3-BH4 groups and two η2-BH4 groups.
基金supported by National Natural Science Foundation of China (No.21174133)Zhejiang Science Foundation for Distinguished Young Scholars (No.LR12B04002)
文摘Transition metal-mediated atom transfer radical polymerization (ATRP) is a "living"Jcontrolled radical polymerization. Recently, there has been widely increasing interest in reducing the high costs of catalyst separation and post-polymerization purification in ATRP. In this work, trolamine was found to significantly enhance the catalytical performance of CuBr]N,N,N',N'-tetrakis(2-pyridylmethyl) ethyle- nediamine (CuBr/TPEN) and CuBr/tris[2-(dimethylamino) ethylamine] (CuBr/MesTREN). With the addition of 25-fold molar amount of trolamine relative to CuBr, the catalyst loadings of CuBr/TPEN and CuBr/Me6TREN were dramatically reduced from a catalyst-to-initiator ratio of 1 to 0.01 and 0.05, respectively. The polymerizations of methyl acrylate, methyl methacrylate and styrene still showed first-order kinetics in the presence of trolamine and produced poly(methyl acrylate), poly(methyl methacrylate) and polystyrene with molecular weights close to theoretical values and low polydispersities. These results indicate that trolamine is a highly effective and versatile promoter for ATRP and is promising for potential industrial application.
基金financially supported by the National Natural Science Foundation of China(No.52130307)。
文摘Owing to its high production volume and wide range of application s,polyethylene has gained a great deal of attention,but its low surface energy and non-polar nature have limited its application in some important fields.In this study,ethylene/11-iodo-1-undecene copolymers were prepared and used as the intermediates to afford a series of imidazolium-based ionomers bearing methanesulfonate(CH_(3)SO_(3)^(-)),trifluoromethanesulfonate(CF_(3)SO_(3)^(-)),or bis(trifluoromethane)sulfonimide(Tf_(2)N^(-))counteranions.The tensile test results showed that the stress-at-break(7.8-25.6 MPa)and the elongation-at-break(445%-847%)of the ionomers could be adjusted by changing the counterion species and the ionic group contents.Most importantly,the ionomers exhibited marvelous antibacterial activities against Staphylococcus aureus(S.aureus)and Escherichia coli(E.coli).The ionomers bearing Tf_(2)N^(-)exhibited antibacterial activities>99%against both S.aureus and E.coli when ionic content reached 9.1%.The imidazolium-based ionomers prepared in this work demonstrated excellent comprehensive properties,especially highefficient and broad-spectrum antibacterial ability,exhibiting the potential fo r the application as the antibacterial materials in packaging,medical,and other fields.