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Songchun Jin - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and crystal structure of bis(cyclopentadienyl)amido complex of Neodymium, [Li(DME)3][(η5-C5H5)2Nd(NPh2)2]
Polyhedron, 1994Co-Authors: Jingwen Guan, Qi Shen, Songchun Jin, Yonghua LinAbstract:Abstract [Li(DME)3] [(η5-C5H5)2Nd(NPh2)2] (1) was synthesized by the reaction of NdCl3 · 2LiCl · nTHF, 2 equivalents of CpNa (Cp = C5H5) and 2 equivalents of LiNPh2 and recrystallized from DME. Complex 1 was characterized by elemental analysis, IR and NMR spectroscopy and X-ray structural analysis. The crystal structure of 1 shows it to consists of [Li(DME)3]+ and [(η5-C5H5)2Nd(NPh2)2]− ion pairs. The Neodymium Atom was coordinated by two η5-bonded cyclopentadienyls and two σ-bonded diphenylamido ligands in a distorted tetrahedral arrangement, with the average distances NdCp(1) = 2.783(8), NdCp(2) = 2.767(9) (Cp indicates the ring carbons) and NdN = 2.428(7)A.
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Synthesis and X-ray crystal structure of an organolanthanide complex [(ButCp)3NdBrLi(THF)3]
Polyhedron, 1992Co-Authors: Sheping Song, Qi Shen, Songchun JinAbstract:(ButCp)2NdCl.2THF reacts with one equivalent of phenyllithum in THF yielding tris(tert-butylcyclopentadienyl)Neodymium lithium bromide tetrahydrofuran, [(ButCP)3 NdBrLi(THF)3], as a by-product, whose structure has been determined by X-ray crystallography. The 10-coordinated Neodymium Atom is bonded to three tert-butyl-cyclopentadienyl groups and one bromine Atom, forming a distorted pseudo-tetrahedron.
Michael G. B. Drew - One of the best experts on this subject based on the ideXlab platform.
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Lanthanide(III)chloride-tetrahydrofuran solvates: structural patterns within the series LnCl3(THF)n, where n = 2,3,3.5 and 4: crystal and molecular structures of [PrCl(μ-Cl)2(THF)2]n, [Nd(μ-Cl)3(H2O)(THF)]n and GdCl3(THF)4
Polyhedron, 1997Co-Authors: Gerald R. Willey, Timothy J. Woodman, Michael G. B. DrewAbstract:Abstract Praseodymium(III), Neodymium(III) and gadolinium(III) chloride adducts with tetrahydrofuran (THF) have been prepared and structurally characterized by X-ray crystallography. Removal of water from the corresponding hexahydrate LnCl3(H2O)6 using thionyl chloride in the presence of excess THF provides light-green cubic crystals of [PrCl3(THF)2]n (1), blue block crystals of [NdCl3(H2O)(THF)]n (2) and colourless needle crystals of GdCl3(THF)4 (3). In 1 each praseodymium Atom is seven-coordinate and is linked to (two) adjacent metal centres by double (μ-Cl)2 halogen bridging units, resulting in a polymeric chain structure. The metal geometry approximates to distorted pentagonal bipyramidal with PrClbridge 2.852(6)–2.891(5), PrClterminal 2.668(6), PrOTHF 2.51(1) (axial), 2.53(2) A (equatorial). In 2 the structure is a two-dimensional cross-linked polymer in which each Neodymium Atom is connected to (three) others via double (μ-Cl)2 halogen bridge bonds. he coordination sphere of each metal centre comprises six chlorine Atoms [NdClbridge 2.816(3)–2.938(3) A] and two oxygen Atoms belonging to a THF molecule [NdO, 2.548(6) A] and a water molecule [NdO, 2.490(7) A], respectively. Hydrogen bonding interactions involving halogen Atoms and coordinated water molecules from adjacent metal units (intermolecular) are observed, OH3·Cl 3.147–3.350 A. In 3 the molecular structure is based on a seven-coordinate pentagonal bipyramidal metal geometry in which two chlorides occupy the axial positions with the other chloride and the four solvate (THF) molecules making up the equatorial plane. GdCl 2.60(2)–2.66(2), GdO 2.40(2)–2.52(3) A. In addition, general comments concerning structural relationships within the series LnCl3(THF)n, where n = 2, 3, 3.5 and 4, are discussed.
Michael Zimmer - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and Crystal Structure Investigations of Trivalent Rare Earth (Y3+, Nd3+, Er3+) Thienyl‐Substituted Methoxides (Eur. J. Inorg. Chem. 15/2008)
European Journal of Inorganic Chemistry, 2008Co-Authors: Michael Veith, Céline Belot, Laurent Guyard, Volker Huch, Michael Knorr, Michael ZimmerAbstract:The cover picture shows the X-ray crystal structure of {Nd[OC(C4H3S)3]3(thf)3}·thf, a new Neodymium thienylmethoxide. The structure determination of this compound reveals a monomer with an approximately octahedral geometry around the Neodymium Atom: this metal centre is surrounded by three tris(2-thienyl)methoxido ligands and three tetrahydrofuran molecules in a facial arrangement. Details are discussed in the article by M. Veith et al. on p. 2397 ff.
Qi Shen - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and crystal structure of bis(cyclopentadienyl)amido complex of Neodymium, [Li(DME)3][(η5-C5H5)2Nd(NPh2)2]
Polyhedron, 1994Co-Authors: Jingwen Guan, Qi Shen, Songchun Jin, Yonghua LinAbstract:Abstract [Li(DME)3] [(η5-C5H5)2Nd(NPh2)2] (1) was synthesized by the reaction of NdCl3 · 2LiCl · nTHF, 2 equivalents of CpNa (Cp = C5H5) and 2 equivalents of LiNPh2 and recrystallized from DME. Complex 1 was characterized by elemental analysis, IR and NMR spectroscopy and X-ray structural analysis. The crystal structure of 1 shows it to consists of [Li(DME)3]+ and [(η5-C5H5)2Nd(NPh2)2]− ion pairs. The Neodymium Atom was coordinated by two η5-bonded cyclopentadienyls and two σ-bonded diphenylamido ligands in a distorted tetrahedral arrangement, with the average distances NdCp(1) = 2.783(8), NdCp(2) = 2.767(9) (Cp indicates the ring carbons) and NdN = 2.428(7)A.
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Synthesis and X-ray crystal structure of an organolanthanide complex [(ButCp)3NdBrLi(THF)3]
Polyhedron, 1992Co-Authors: Sheping Song, Qi Shen, Songchun JinAbstract:(ButCp)2NdCl.2THF reacts with one equivalent of phenyllithum in THF yielding tris(tert-butylcyclopentadienyl)Neodymium lithium bromide tetrahydrofuran, [(ButCP)3 NdBrLi(THF)3], as a by-product, whose structure has been determined by X-ray crystallography. The 10-coordinated Neodymium Atom is bonded to three tert-butyl-cyclopentadienyl groups and one bromine Atom, forming a distorted pseudo-tetrahedron.
Fosong Wang - One of the best experts on this subject based on the ideXlab platform.
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Preparation of high cis‐1,4 polyisoprene with narrow molecular weight distribution via coordinative chain transfer polymerization
Journal of Polymer Science Part A: Polymer Chemistry, 2010Co-Authors: Changliang Fan, Hongguang Cai, Quanquan Dai, Chenxi Bai, Xuequan Zhang, Fosong WangAbstract:High cis-1,4 polyisoprene with narrow molecular weight distribution has been prepared via coordinative chain transfer polymerization (CCTP) using a homogeneous rare earth catalyst composed of Neodymium versatate (Nd(vers)(3)), dimethyldichlorosilane (Me2SiCl2), and diisobutylaluminum hydride (Al(i-Bu)(2)H) which has strong chain transfer affinity is used as both cocatalyst and chain transfer agent (CTA). Differentiating from the typical chain shuttling polymerization where dual-catalysts/CSA system has been used, one catalyst/CTA system is used in this work, and the growing chain swapping between the identical active sites leads to the formation of high cis-1,4 polyisoprene with narrowly distributed molecular weight. Sequential polymerization proves that irreversible chain termination reactions are negligible. Much smaller molecular weight of polymer obtained than that of stoichiometrically calculated illuminates that, differentiating from the typical living polymerization, several polymer chains can be produced by one Neodymium Atom. The effectiveness of Al(i-Bu)(2)H as a CTA is further testified by much broad molecular weight distribution of polymer when triisobutylaluminum (Al(i-Bu)(3)), a much weaker chain transfer agent, is used as cocatalyst instead of Al(i-Bu)(2)H. Finally, CCTP polymerization mechanism is validated by continuously decreased M-w/M-n value of polymer when increasing concentration of Al(i-Bu)(2)H extra added in the Nd(ver)(3)/Me2SiCl2/Al(i-Bu)(3) catalyst system. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4768-4774, 2010
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Preparation of high cis-1,4 polyisoprene with narrow molecular weight distribution via coordinative chain transfer polymerization Part A Polymer chemistry
Journal of Polymer Science, 2010Co-Authors: Changliang Fan, Bai Chenxi, Hongguang Cai, Quanquan Dai, Zhang Xuequan, Fosong WangAbstract:High cis-1,4 polyisoprene with narrow molecular weight distribution has been prepared via coordinative chain transfer polymerization (CCTP) using a homogeneous rare earth catalyst composed of Neodymium versatate (Nd(vers)₃), dimethyldichlorosilane (Me₂SiCl₂), and diisobutylaluminum hydride (Al(i-Bu)₂H) which has strong chain transfer affinity is used as both cocatalyst and chain transfer agent (CTA). Differentiating from the typical chain shuttling polymerization where dual-catalysts/CSA system has been used, one catalyst/CTA system is used in this work, and the growing chain swapping between the identical active sites leads to the formation of high cis-1,4 polyisoprene with narrowly distributed molecular weight. Sequential polymerization proves that irreversible chain termination reactions are negligible. Much smaller molecular weight of polymer obtained than that of stoichiometrically calculated illuminates that, differentiating from the typical living polymerization, several polymer chains can be produced by one Neodymium Atom. The effectiveness of Al(i-Bu)₂H as a CTA is further testified by much broad molecular weight distribution of polymer when triisobutylaluminum (Al(i-Bu)₃), a much weaker chain transfer agent, is used as cocatalyst instead of Al(i-Bu)₂H. Finally, CCTP polymerization mechanism is validated by continuously decreased Mw/Mn value of polymer when increasing concentration of Al(i-Bu)₂H extra added in the Nd(ver)₃/Me₂SiCl₂/Al(i-Bu)₃ catalyst system.
