Mono-guanidinate complexes of lanthanum: synthesis, structure and their use in lactide polymerization

被引：154

作者：

Giesbrecht, GR

Whitener, GD

Arnold, J ^{[1
]}

机构：

[1] Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA

[2] Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA

来源：

JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS | 2001年 / 06期

关键词：

catalysis; homogeneous; lanthanides; lanthanum;

D O I：

10.1039/b008164g

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

La[N(SiMe3)(2)](3) reacted with 1,3-dicyclohexylcarbodiimide in refluxing toluene to yield the mono-guanidinate complex La[CyNC(N(SiMe3)(2))NCy](N(SiMe3)(2))(2) 1. Compound 1 is monomeric in solution; X-ray structural analysis reveals an unassociated complex in the solid state, with a four-coordinate lanthanum center. Complex 1 reacts with 2,6-di-tert-butylphenol (2 equivalents) in cold pentane to yield the bis(phenoxide) complex La[CyNC(N(SiMe3)(2))NCy]((OC6H3Bu2)-Bu-t-2,6)(2). X-Ray analysis indicates a similar structure to that of 1, with a four-coordinate lanthanum center coordinated by a single guanidinate ligand and two phenoxide groups. This compound catalyses the ring-opening polymerization of D,L-lactide to polylactide. Although high molecular weight polymer is obtained, polydispersities are broad and no control over the stereochemistry of the polymer is observed.

引用

页码：923 / 927

页数：5

共 58 条

[1] ORGANOMETALLIC COMPOUNDS OF THE LANTHANOIDES .26. SOME NOVEL HALIDE-DERIVATIVES AND ALKYL-DERIVATIVES OF PENTAMETHYLCYCLOPENTADIENYLLANTHANUM, LANTHANUM-PRASEODYMIUM, LANTHANUM-YTTERBIUM AND LANTHANUM-LUTETIUM
ALBRECHT, I
HAHN, E
PICKARDT, J
SCHUMANN, H
[J]. INORGANICA CHIMICA ACTA-F-BLOCK ELEMENTS ARTICLES AND LETTERS, 1985, 110 (02): : 145 - 147
[2] [Anonymous], 1992, Polym. Prepr. (Am. Chem Soc. Div. Polym Chem.)
[3] Convenient preparation of lanthanide aryloxides from lanthanide nitrate polyether complexes and the crystal structure of [La(OC(6)H(3)Me(2)-2,6)(3)(MeO(CH2CH2O)(4)Me)]
Aspinall, HC
Williams, M
[J]. INORGANIC CHEMISTRY, 1996, 35 (01) : 255 - 257
[4] Yttrium alkyl and benzyl complexes with amino-amidinate monoanionic ancillary ligands
Bambirra, S
Brandsma, MJR
Brussee, EAC
Meetsma, A
Hessen, B
Teuben, JH
[J]. ORGANOMETALLICS, 2000, 19 (16) : 3197 - 3204
[5] Intermolecular chain transfer to polymer with chain scission: General treatment and determination of k(p)/k(tr) in L,L-lactide polymerization
Baran, J
Duda, A
Kowalski, A
Szymanski, R
Penczek, S
[J]. MACROMOLECULAR RAPID COMMUNICATIONS, 1997, 18 (04) : 325 - 333
[6] BERO M, 1990, MAKROMOL CHEM, V191, P2287
[7] ON THE SYNTHESIS OF MONOPENTAMETHYLCYCLOPENTADIENYL DERIVATIVES OF YTTRIUM, LANTHANUM, AND CERIUM
BOOIJ, M
KIERS, NH
HEERES, HJ
TEUBEN, JH
[J]. JOURNAL OF ORGANOMETALLIC CHEMISTRY, 1989, 364 (1-2) : 79 - 86
[8] BORGNE AL, 1995, MACROMOL RAPID COMM, V15, P955
[9] 3-COORDINATION IN LANTHANIDE CHEMISTRY - TRIS[BIS(TRIMETHYLSILYL)AMIDO]LANTHANIDE(III) COMPOUNDS
BRADLEY, DC
GHOTRA, JS
HART, FA
[J]. JOURNAL OF THE CHEMICAL SOCIETY-CHEMICAL COMMUNICATIONS, 1972, (06) : 349 - &
[10] (Aminotroponiminato)yttrium amides as catalysts in alkyne hydroamination
Burgstein, MR
Berberich, H
Roesky, PW
[J]. ORGANOMETALLICS, 1998, 17 (08) : 1452 - 1454

← 1 2 3 4 5 6 →