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.
(CH_3)_4C_2(C_5H_4)_2Sm(C_5H_5)OC_4H_, Mr=499.4, orthorhombic, Cc2a, a=11.696(6), b=12.539(5), c=29.432(15), V=4316(4)~, Z=8, Dc=1.54g. cm^(-3), μ (MoKα)=27.8cm^(-1), F(000)=2024, R=0.077 for 1833 observed reflectio...(CH_3)_4C_2(C_5H_4)_2Sm(C_5H_5)OC_4H_, Mr=499.4, orthorhombic, Cc2a, a=11.696(6), b=12.539(5), c=29.432(15), V=4316(4)~, Z=8, Dc=1.54g. cm^(-3), μ (MoKα)=27.8cm^(-1), F(000)=2024, R=0.077 for 1833 observed reflections. In the molecule the samarium atom is bonded to three cyclopentadienyl rings and an oxygen of tetrahydrofuran(THF). The three centroids of the cyclopentadienyl rings and the oxygen form a tetrahedral configuration around the Sm(Ⅲ) atom, The average Sm-C(η~) bond distances for the three cyclopentadienyl groups are 2.72(3), 2.76(3), 2.78(8) respectively, and Sm-0 bond is 2.53(1).展开更多
The copolymerization process of triphenylmethyl methacrylate (TrMA) and methylmethacrylate (MMA) using chiral anionic complex initiator (-) SP-FlLi (Scheme 1) has beenstudied in toluene and THF, respectively. The copo...The copolymerization process of triphenylmethyl methacrylate (TrMA) and methylmethacrylate (MMA) using chiral anionic complex initiator (-) SP-FlLi (Scheme 1) has beenstudied in toluene and THF, respectively. The copolymer obtained in toluene possessed muchhigher specific rotation than that in THF. These copolymers have shown a tendency to a random and a like alternating structure, respectively.展开更多
Owing to the importance of Sharpless epoxidation reaction in asymmetric synthesis,the regio-and stereoselective opening of the resulting 2, 3-epoxyalcohols has become a topicof current interest.Although many nucleophi...Owing to the importance of Sharpless epoxidation reaction in asymmetric synthesis,the regio-and stereoselective opening of the resulting 2, 3-epoxyalcohols has become a topicof current interest.Although many nucleophiles attack Cin high selectivity under the actionof Ti（OR）4,some of them like halides, azide, and cyanide only show moderate propensity展开更多
A dimeric yttrium complex [Y（C5Me4SiMe3）{μ-O（CH2）3CH3} {N（SiHMe2）2}]2 （1） was isolated as one of the byproducts from the reaction of Y {N（SiHMe2）3}3（THF）2 with C5Me4HSiMe3 in 1 ： 1.1 molar ratio in tolue...A dimeric yttrium complex [Y（C5Me4SiMe3）{μ-O（CH2）3CH3} {N（SiHMe2）2}]2 （1） was isolated as one of the byproducts from the reaction of Y {N（SiHMe2）3}3（THF）2 with C5Me4HSiMe3 in 1 ： 1.1 molar ratio in toluene at 100 ℃ for 2 d. Complex 1 was characterized by elemental analysis, NMR spectroscopy, FT-IR spectroscopy, and X-ray single crystal structure analysis. X-ray diffractions revealed that complex 1 was a symmetric dimer, and the center metal y^3＋ was six-coordinated by one nitrogen atom from the amide group, two bridging oxygen atoms from the O（CH2）3CH3 groups, and one cyclopentadienyl ring in η^5-fashion to adopt a distorted tetrahedron geometry. The formation of complex 1 was postulated to be a result fxom C O bond cleavage reaction of THF.展开更多
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(CH_3)_4C_2(C_5H_4)_2Sm(C_5H_5)OC_4H_, Mr=499.4, orthorhombic, Cc2a, a=11.696(6), b=12.539(5), c=29.432(15), V=4316(4)~, Z=8, Dc=1.54g. cm^(-3), μ (MoKα)=27.8cm^(-1), F(000)=2024, R=0.077 for 1833 observed reflections. In the molecule the samarium atom is bonded to three cyclopentadienyl rings and an oxygen of tetrahydrofuran(THF). The three centroids of the cyclopentadienyl rings and the oxygen form a tetrahedral configuration around the Sm(Ⅲ) atom, The average Sm-C(η~) bond distances for the three cyclopentadienyl groups are 2.72(3), 2.76(3), 2.78(8) respectively, and Sm-0 bond is 2.53(1).
文摘The copolymerization process of triphenylmethyl methacrylate (TrMA) and methylmethacrylate (MMA) using chiral anionic complex initiator (-) SP-FlLi (Scheme 1) has beenstudied in toluene and THF, respectively. The copolymer obtained in toluene possessed muchhigher specific rotation than that in THF. These copolymers have shown a tendency to a random and a like alternating structure, respectively.
文摘Owing to the importance of Sharpless epoxidation reaction in asymmetric synthesis,the regio-and stereoselective opening of the resulting 2, 3-epoxyalcohols has become a topicof current interest.Although many nucleophiles attack Cin high selectivity under the actionof Ti（OR）4,some of them like halides, azide, and cyanide only show moderate propensity
基金Project supported by Zhejiang Provincial Natural Science Foundation (Y4090617)Science and Technology Department of Zhejiang Province (2010R10020)+1 种基金Key Laboratory of Organic Synthesis of Jiangsu Province (KJS0907)State Key Laboratory of Rare Earth Resource Utilization (RERU2011020)
文摘A dimeric yttrium complex [Y（C5Me4SiMe3）{μ-O（CH2）3CH3} {N（SiHMe2）2}]2 （1） was isolated as one of the byproducts from the reaction of Y {N（SiHMe2）3}3（THF）2 with C5Me4HSiMe3 in 1 ： 1.1 molar ratio in toluene at 100 ℃ for 2 d. Complex 1 was characterized by elemental analysis, NMR spectroscopy, FT-IR spectroscopy, and X-ray single crystal structure analysis. X-ray diffractions revealed that complex 1 was a symmetric dimer, and the center metal y^3＋ was six-coordinated by one nitrogen atom from the amide group, two bridging oxygen atoms from the O（CH2）3CH3 groups, and one cyclopentadienyl ring in η^5-fashion to adopt a distorted tetrahedron geometry. The formation of complex 1 was postulated to be a result fxom C O bond cleavage reaction of THF.
