کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1325244 1499945 2009 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Mono(amidinate) rare earth metal bis(alkyl) complexes: Synthesis, structure and their activity for l-lactide polymerization
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Mono(amidinate) rare earth metal bis(alkyl) complexes: Synthesis, structure and their activity for l-lactide polymerization
چکیده انگلیسی

Alkane elimination reaction between Ln(CH2SiMe3)3(THF)2 (Ln = Y, Lu) with one equivalent of the amidines with different steric demanding HL ([CyC(N-2,6-iPr2C6H3)2]H (HL1), [CyC(N-2,6-Me2C6H3)2]H (HL2), [PhC(N-2,6-Me2C6H3)2]H (HL3)) in THF afforded a series of mono(amidinate) rare earth metal bis(alkyl) complexes [CyC(N-2,6-iPr2C6H3)2]Ln(CH2SiMe3)2(THF) (Ln = Y (1), Lu (3)), [CyC(N-2,6-Me2C6H3)2]Ln(CH2SiMe3)2(THF)2 (Ln = Y (4), Lu (6)), and [PhC(N-2,6-Me2C6H3)2]Y(CH2SiMe3)2(THF)2 (7) in 75–89% isolated yields. For the early lanthanide metal Nd, THF slurry of NdCl3 was stirred with three equiv of LiCH2SiMe3 in THF, followed by addition of one equiv of the amidines HL1 or HL2 gave an “ate” complex [CyC(N-2,6-iPr2C6H3)2]Nd(CH2SiMe3)2(μ-Cl)Li(THF)3(2) in 48% yield and a neutral [CyC(N-2,6-Me2C6H3)2]Nd(CH2SiMe3)2(THF)2(5) in 52% yield, respectively. They were characterized by elemental analysis, FT-IR, NMR spectroscopy (except for 2 and 5 for their strong paramagnetic property). Complexes 2, 3, 4 and 5 were subjected to X-ray single crystal structure determination. These neutral mono(amidinate) rare earth metal bis(alkyl) complexes showed activity towards l-lactide polymerization to give high molecular weight and narrow molecular weight distribution polymers.

Alkane elimination between rare earth metal tris(alkyl) complexes and 1 equiv. of the amidines afforded mono(amidinate) rare earth metal bis(alkyl) complexes [CyC(N-2,6-iPr2C6H3)2]Ln(CH2SiMe3)2(THF) (Ln = Y (1), Lu (3)), [CyC(N-2,6-iPr2C6H3)2]Nd(CH2SiMe3)2(μ-Cl)Li(THF)3 (2), [CyC(N-2,6-Me2C6H3)2]Ln(CH2SiMe3)2(THF)2 (Ln = Y (4), Nd (5), Lu (6)), and [PhC(N-2,6-Me2C6H3)2]Y(CH2SiMe3)2(THF)2 (7). These complexes showed activity towards l-lactide polymerization.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Organometallic Chemistry - Volume 694, Issues 9–10, 15 April 2009, Pages 1289–1296
نویسندگان
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