Neutral nickel sigma -acetylide complex [Ni(C=CPh)(2)(PBu3)(2)] is a novel initiator for the polymerization of styrene in CHCl3 over a range of polymerization temperature from 40 degreesC to 60 degreesC. The polystyre...Neutral nickel sigma -acetylide complex [Ni(C=CPh)(2)(PBu3)(2)] is a novel initiator for the polymerization of styrene in CHCl3 over a range of polymerization temperature from 40 degreesC to 60 degreesC. The polystyrene obtained was a syndio-rich atactic polymer and its weight-average molecular weight reached 279000. The mechanism of the polymerization was discussed and a radical mechanism was proposed.展开更多
Phenyl isocyanate was for the first time successfully polymerized by divalent samarium complex (ArO)2Sm(THF)4. The monomer concentration and temperatur affected the polymerization greatly.
The polymerization of acrylonitrile initiated by organolanthanide complexes alone is studied for the first time. The effect of polymerization conditions on catalytic activity of the title complex and molecular weight ...The polymerization of acrylonitrile initiated by organolanthanide complexes alone is studied for the first time. The effect of polymerization conditions on catalytic activity of the title complex and molecular weight of the polymers produced have been studied.展开更多
Styrene-acrylic acid copolymer (SAAC)-supported iron complex (SAAC·Fe)was characterized and the effect of the characteristic parameters on the catalytic activity of the complex was investigated. IR spectrum sugge...Styrene-acrylic acid copolymer (SAAC)-supported iron complex (SAAC·Fe)was characterized and the effect of the characteristic parameters on the catalytic activity of the complex was investigated. IR spectrum suggested that the complex SAAC·Fe possesses a structure of(C)and the Fe-O bond is higher in covalency.The complex SAAC·Fe with the structure of(C)shoved a higher catalytic activity in butadiene polymerization. When Fe/-COOH molar ratio in SAAC·Fe was about 0.2 the complex gave optimum catalytic activity. The catalytic activity of SAAC·Fe with the higher content of long sequence of acrylic acid units was low. When the content of the short sequence of acrylic acid units was predominant and at the same time the content of the short sequence was approximately equal to that of the long sequence for stryrene, the activity of the complex was high.展开更多
The characteristics of styrene-acrylic acid copolymer supported lanthanide complexes (SAAC Ln) (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tin, Yb, and Lu) were described. A comparison of the activities of SAAC...The characteristics of styrene-acrylic acid copolymer supported lanthanide complexes (SAAC Ln) (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tin, Yb, and Lu) were described. A comparison of the activities of SAAC·Ln was made. It was found that in the polymerization of butadiene, a peak in activity appeared at Nd and Pr, Sin, Eu and the heavy lanthanides exhibited low or no activities. The effects of some factors on the activities were discussed. The microstructure of the polymers obtained with all the lanthanides in the series were the same and the content of cis-1, 4 polybutadiene attained was more than 98%.展开更多
The catalytic activities of nine neutral nickel and palladium a-acetylide complexes [M=(C=CR)2(PR'3)2)M=Ni,Pd; R=Ph,CH2OH,CH2OOCH3,CH2OOCPh,CH2OOCPhOH-o; R'=Ph,Bu] are compared.Among them,Ni(Cs=CPh)2-(PBuj)2 s...The catalytic activities of nine neutral nickel and palladium a-acetylide complexes [M=(C=CR)2(PR'3)2)M=Ni,Pd; R=Ph,CH2OH,CH2OOCH3,CH2OOCPh,CH2OOCPhOH-o; R'=Ph,Bu] are compared.Among them,Ni(Cs=CPh)2-(PBuj)2 shows the highest catalytic activity and gives the polystyrene with high molecular weight(Mw=188800)and a syndio-rich microstructure.The catalytic behavior of transition metal acetylides is related to metal,phosphine,and alkynyl ligands bonded to the metal atoms.展开更多
Divalent organosamarium and organoytterbium complexes as a kind of strong reducing agent not only can react with electron rich agents such as halides, aldehyde, ketone, unsaturated hydrocarbon and the compounds contai...Divalent organosamarium and organoytterbium complexes as a kind of strong reducing agent not only can react with electron rich agents such as halides, aldehyde, ketone, unsaturated hydrocarbon and the compounds containing active hydrogen but also can catalyze hydrogenation of alkyne, ethylene polymerization and methyl methacrylate polymerization. More and more interests and attention have been given to the synthesis, structure and catalytic activity of divalent organolanthanide complexes in recent years,展开更多
Activated by methylaluminoxane, mononuclear bis(hydroxyindanone-iminate)nickel complexes Ni[ArN == CC_2H_3(CH3)C_6H_2(R)O]_2 (Ar = 2,6-i-Pr2C6H3, R = Me (1), R = Cl (2), and R = H (3)) showed good activity for the sty...Activated by methylaluminoxane, mononuclear bis(hydroxyindanone-iminate)nickel complexes Ni[ArN == CC_2H_3(CH3)C_6H_2(R)O]_2 (Ar = 2,6-i-Pr2C6H3, R = Me (1), R = Cl (2), and R = H (3)) showed good activity for the styrene polymerization. The effect of many reaction parameters including the Al/Ni ratio, tempera- ture, and reaction time on catalytic activities of catalytic systems and the molecular weights of the ob- tained polystyrene was ascertained. The highest activity of 1.34×105 g(PS)·mol^(-1)(Ni)·h^(-1) was obtained under the optimum reaction condition. The 13C NMR spectra of the polymers revealed that the polymer was isotactic-rich atactic polystyrene. And the coordination mechanism was confirmed by the analyses of the polymer chain end-groups.展开更多
The catalytic activity of a series of indenylnickel（Ⅱ） halides： （1-R-Ind）Ni（PPh3）X （R=ethyl, cyclopentyl and benzyl, while X=Cl, Br and I）, towards styrene polymerization was studied in the presence of NaBPh...The catalytic activity of a series of indenylnickel（Ⅱ） halides： （1-R-Ind）Ni（PPh3）X （R=ethyl, cyclopentyl and benzyl, while X=Cl, Br and I）, towards styrene polymerization was studied in the presence of NaBPh4 and PPh3. The catalytic property of these halides was related to the substituent group on the indenyl ligand and the halogen atom bonded to the metal atom. Among them, the （1-Et-Ind）Ni（PPh3）Cl/NaBPha/PPh3 system showed the highest activity for the polymerization of styrene, and the polystyrene obtained was a syndio-rich （rr triad） atactic polymer with Mn values in the range of 103--104. The mechanism of the styrene polymerization initiated by the （1-Et-Ind）Ni（PPh3）Cl/NaBPha/PPh3 system was studied.展开更多
文摘Neutral nickel sigma -acetylide complex [Ni(C=CPh)(2)(PBu3)(2)] is a novel initiator for the polymerization of styrene in CHCl3 over a range of polymerization temperature from 40 degreesC to 60 degreesC. The polystyrene obtained was a syndio-rich atactic polymer and its weight-average molecular weight reached 279000. The mechanism of the polymerization was discussed and a radical mechanism was proposed.
文摘Phenyl isocyanate was for the first time successfully polymerized by divalent samarium complex (ArO)2Sm(THF)4. The monomer concentration and temperatur affected the polymerization greatly.
文摘The polymerization of acrylonitrile initiated by organolanthanide complexes alone is studied for the first time. The effect of polymerization conditions on catalytic activity of the title complex and molecular weight of the polymers produced have been studied.
文摘Styrene-acrylic acid copolymer (SAAC)-supported iron complex (SAAC·Fe)was characterized and the effect of the characteristic parameters on the catalytic activity of the complex was investigated. IR spectrum suggested that the complex SAAC·Fe possesses a structure of(C)and the Fe-O bond is higher in covalency.The complex SAAC·Fe with the structure of(C)shoved a higher catalytic activity in butadiene polymerization. When Fe/-COOH molar ratio in SAAC·Fe was about 0.2 the complex gave optimum catalytic activity. The catalytic activity of SAAC·Fe with the higher content of long sequence of acrylic acid units was low. When the content of the short sequence of acrylic acid units was predominant and at the same time the content of the short sequence was approximately equal to that of the long sequence for stryrene, the activity of the complex was high.
文摘The characteristics of styrene-acrylic acid copolymer supported lanthanide complexes (SAAC Ln) (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tin, Yb, and Lu) were described. A comparison of the activities of SAAC·Ln was made. It was found that in the polymerization of butadiene, a peak in activity appeared at Nd and Pr, Sin, Eu and the heavy lanthanides exhibited low or no activities. The effects of some factors on the activities were discussed. The microstructure of the polymers obtained with all the lanthanides in the series were the same and the content of cis-1, 4 polybutadiene attained was more than 98%.
文摘The catalytic activities of nine neutral nickel and palladium a-acetylide complexes [M=(C=CR)2(PR'3)2)M=Ni,Pd; R=Ph,CH2OH,CH2OOCH3,CH2OOCPh,CH2OOCPhOH-o; R'=Ph,Bu] are compared.Among them,Ni(Cs=CPh)2-(PBuj)2 shows the highest catalytic activity and gives the polystyrene with high molecular weight(Mw=188800)and a syndio-rich microstructure.The catalytic behavior of transition metal acetylides is related to metal,phosphine,and alkynyl ligands bonded to the metal atoms.
基金Project supported by the National Natural Science Foundation of China Academia Sinica and Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Academia Sinica.
文摘Divalent organosamarium and organoytterbium complexes as a kind of strong reducing agent not only can react with electron rich agents such as halides, aldehyde, ketone, unsaturated hydrocarbon and the compounds containing active hydrogen but also can catalyze hydrogenation of alkyne, ethylene polymerization and methyl methacrylate polymerization. More and more interests and attention have been given to the synthesis, structure and catalytic activity of divalent organolanthanide complexes in recent years,
基金the National Natural Science Foundation of China (Grant Nos. 20531020, 20721063, and 20771028)Shanghai Leading Academic Discipline Project (Grant No. B108)+1 种基金the National Basic Research Program of China (Grant No. 2005CB623800) Shanghai Science and Technology Committee (Grant No. 06XD14002)
文摘Activated by methylaluminoxane, mononuclear bis(hydroxyindanone-iminate)nickel complexes Ni[ArN == CC_2H_3(CH3)C_6H_2(R)O]_2 (Ar = 2,6-i-Pr2C6H3, R = Me (1), R = Cl (2), and R = H (3)) showed good activity for the styrene polymerization. The effect of many reaction parameters including the Al/Ni ratio, tempera- ture, and reaction time on catalytic activities of catalytic systems and the molecular weights of the ob- tained polystyrene was ascertained. The highest activity of 1.34×105 g(PS)·mol^(-1)(Ni)·h^(-1) was obtained under the optimum reaction condition. The 13C NMR spectra of the polymers revealed that the polymer was isotactic-rich atactic polystyrene. And the coordination mechanism was confirmed by the analyses of the polymer chain end-groups.
基金Project supported by the National Natural Science Foundation of China （No. 20272040）.
文摘The catalytic activity of a series of indenylnickel（Ⅱ） halides： （1-R-Ind）Ni（PPh3）X （R=ethyl, cyclopentyl and benzyl, while X=Cl, Br and I）, towards styrene polymerization was studied in the presence of NaBPh4 and PPh3. The catalytic property of these halides was related to the substituent group on the indenyl ligand and the halogen atom bonded to the metal atom. Among them, the （1-Et-Ind）Ni（PPh3）Cl/NaBPha/PPh3 system showed the highest activity for the polymerization of styrene, and the polystyrene obtained was a syndio-rich （rr triad） atactic polymer with Mn values in the range of 103--104. The mechanism of the styrene polymerization initiated by the （1-Et-Ind）Ni（PPh3）Cl/NaBPha/PPh3 system was studied.
