经过三步反应合成了红色晶体,双六甲基二硅胺基二甲基硅基环戊二烯基稀土二价镱配合物[η5-C5H4S iM e2N(S iM e3)2]2Yb(Ⅱ).2THF,X射线衍射结果表明,[η5-C5H4S iM e2N(S iM e3)2]2Yb(Ⅱ).2THF属于单斜晶系,空间群为P21/c,a=1.646 87(1...经过三步反应合成了红色晶体,双六甲基二硅胺基二甲基硅基环戊二烯基稀土二价镱配合物[η5-C5H4S iM e2N(S iM e3)2]2Yb(Ⅱ).2THF,X射线衍射结果表明,[η5-C5H4S iM e2N(S iM e3)2]2Yb(Ⅱ).2THF属于单斜晶系,空间群为P21/c,a=1.646 87(12)nm,b=0.907 70(6)nm,c=3.049 4(3)nm,β=93.642(4),°V=4.549 3(6)nm3,Z=2,C34H72N2O2S i6Yb,Mr=1 905.41,Dc=1.288 g/cm3,F(000)=1 840.00,μ(MoKα)=22.42 cm-1(λ=0.071 070 nm)。收集独立衍射点7 814个,将其中I>3.00σ(1)的用于结构解析,用全矩阵最小二乘法校正,得最终偏离因子R=0.039,Rw=0.050。8配位的中心镱原子与2个四氢呋喃的氧及2个环戊二烯基配位形成扭曲的四面体结构。展开更多
The reaction of LnCl 3 with two equivalents of 2,4-dimethyl-pentadienyl potassium affords (2,4-C 7H 11 ) 3Ln(Ln=Dy,Er). The compound (2,4-C 7H 11 ) 3Dy(1), crystallized from a mixed solvent of hexane and THF has a tri...The reaction of LnCl 3 with two equivalents of 2,4-dimethyl-pentadienyl potassium affords (2,4-C 7H 11 ) 3Ln(Ln=Dy,Er). The compound (2,4-C 7H 11 ) 3Dy(1), crystallized from a mixed solvent of hexane and THF has a triclinic space group Pl with a =1 270 2(2) nm, b = 1 290 8(2) nm, c =0 847 9(2) nm, α =91 48(2)°, β =108 41(2)°, γ =118 41(2)°, Z =2. The compound (2,4-C 7H 11 ) 3Er(2) was crystallized from toluene in triclinic P l- with a =0 909 5(3) nm, b =1 407 2(3) nm, c =1.657 7(6) nm, α =106 66(2)°, β =93 77(3)°, γ =89 76(2)°, Z =4. Both structures were solved by using direct methods and refined by block-matrix least-squares to final values of R =0 039 for 1 and R =0 067 for 2. A comparison of some significant structural parameters in (2,4-C 7H 11 ) 3Ln(Ln=Dy,Er) with those from other analogues (2,4-C 7H 11 ) 3Ln(Ln=Nd,Gd) was made.展开更多
Lateral diffusion of diblock copolymer residing on the interfaces between two immiscible liquids is investigated at single molecular level. Fluorescence correlation spectroscopy was used to study the diffusion of fluo...Lateral diffusion of diblock copolymer residing on the interfaces between two immiscible liquids is investigated at single molecular level. Fluorescence correlation spectroscopy was used to study the diffusion of fluorescence-labeled diblock copolymer,polystyrene-b-polyisoprene, at the interface formed between two immiscible liquids. The interfaces are formed between N,N-dimethylformamide(DMF) and a few immiscible liquids, n-alkane and polyisoprene. Interfacial diffusion coefficient of the diblock copolymer probe is found to decrease monotonously with the increase of the molecular length of the interface constituting liquids. The decrease of diffusion coefficient follows the prediction by Einstein relation using the viscosity of the constituting liquids as the variables only for interfaces between DMF and very small n-alkanes. For interfaces formed between DMF and bigger alkanes and especially between DMF and polyisoprene, the diffusion coefficient is much higher than the calculated value,indicating that the probe molecule starts to probe the much less viscous interfacial region because the interfacial width gets larger,whose thickness is comparable to the molecule size of the liquids.展开更多
基金special fuuds for Major State Basic Research projects!(project No.G19990 6 480 1)
文摘The reaction of LnCl 3 with two equivalents of 2,4-dimethyl-pentadienyl potassium affords (2,4-C 7H 11 ) 3Ln(Ln=Dy,Er). The compound (2,4-C 7H 11 ) 3Dy(1), crystallized from a mixed solvent of hexane and THF has a triclinic space group Pl with a =1 270 2(2) nm, b = 1 290 8(2) nm, c =0 847 9(2) nm, α =91 48(2)°, β =108 41(2)°, γ =118 41(2)°, Z =2. The compound (2,4-C 7H 11 ) 3Er(2) was crystallized from toluene in triclinic P l- with a =0 909 5(3) nm, b =1 407 2(3) nm, c =1.657 7(6) nm, α =106 66(2)°, β =93 77(3)°, γ =89 76(2)°, Z =4. Both structures were solved by using direct methods and refined by block-matrix least-squares to final values of R =0 039 for 1 and R =0 067 for 2. A comparison of some significant structural parameters in (2,4-C 7H 11 ) 3Ln(Ln=Dy,Er) with those from other analogues (2,4-C 7H 11 ) 3Ln(Ln=Nd,Gd) was made.
基金supported by the National Natural Science Foundation of China (51573197, 21544012)the Instrumentation Developments Funding of Chinese Academy of Sciences
文摘Lateral diffusion of diblock copolymer residing on the interfaces between two immiscible liquids is investigated at single molecular level. Fluorescence correlation spectroscopy was used to study the diffusion of fluorescence-labeled diblock copolymer,polystyrene-b-polyisoprene, at the interface formed between two immiscible liquids. The interfaces are formed between N,N-dimethylformamide(DMF) and a few immiscible liquids, n-alkane and polyisoprene. Interfacial diffusion coefficient of the diblock copolymer probe is found to decrease monotonously with the increase of the molecular length of the interface constituting liquids. The decrease of diffusion coefficient follows the prediction by Einstein relation using the viscosity of the constituting liquids as the variables only for interfaces between DMF and very small n-alkanes. For interfaces formed between DMF and bigger alkanes and especially between DMF and polyisoprene, the diffusion coefficient is much higher than the calculated value,indicating that the probe molecule starts to probe the much less viscous interfacial region because the interfacial width gets larger,whose thickness is comparable to the molecule size of the liquids.
