Organometallic Chemistry Laboratory, Ningbo Institute of Technology, Zhejiang University, Ningbo 315100, People's Republic of China.
Dalton Trans. 2013 Mar 21;42(11):4040-51. doi: 10.1039/c2dt32868b. Epub 2013 Jan 23.
Amine elimination of rare-earth-metal tris(silylamide) complexes LnN(SiHMe(2))(2)(THF)(x) (Ln = Sc, x = 1; Ln = Y, x = 2) with 1 equiv. of the amidines [PhC(N-2,6-R(2)C(6)H(3))(2)]H afforded a series of neutral mono(amidinate) rare-earth-metal bis(silylamide) complexes [PhC(N-2,6-R(2)C(6)H(3))(2)]LnN(SiHMe(2))(2)(THF)(y) (R = Me, Ln = Sc, y = 0 (1); R = Me, Ln = Y, y = 1 (2); R = (i)Pr, Ln = Y, y = 1 (3)). Treatment of 1-3 with 1 equiv. of [Ph(3)C][B(C(6)F(5))(4)] in THF generated the corresponding cationic amidinate rare-earth-metal mono(silylamide) complexes [{PhC(N-2,6-R(2)C(6)H(3))(2)}Ln{N(SiHMe(2))(2)}(THF)(3)][B(C(6)F(5))(4)] (R = Me, Ln = Sc (4), Y (5); R = (i)Pr, Ln = Y (6)). When 1-3 were first activated with 1 equiv. of [Ph(3)C][B(C(6)F(5))(4)] in toluene, then treatment with THF gave the unexpected cationic amidinate rare-earth-metal amide complexes [{PhC(N-2,6-R(2)C(6)H(3))(2)}LnN{SiHMe(2)}{SiMe(2)N(SiHMe(2))(2)}(THF)(n)][B(C(6)F(5))(4)] (R = Me, Ln = Sc, n = 2 (7); R = Me, Ln = Y, n = 4 (8); R = (i)Pr, Ln = Y, n = 2 (9)). The reaction of 1-3 with excess AlMe(3) produced the heterometallic Ln/Al methyl complexes [PhC(N-2,6-R(2)C(6)H(3))(2)]Ln(μ-Me)(2)AlMe(2) (R = Me, Ln = Sc (10), Y (11); R = (i)Pr, Ln = Y (12)). All these complexes were well-characterized by elemental analysis, NMR spectroscopy and FT-IR spectroscopy. 2, 6 and 11 were further structurally authenticated by X-ray crystallography. The binary catalyst system of 1/[Ph(3)C][B(C(6)F(5))(4)] in toluene showed activity toward 3,4-selective polymerization of isoprene, whilst the tertiary catalyst systems of 1-3/[Ph(3)C][B(C(6)F(5))(4)]/AlMe(3) were highly active for cis-1,4-selective polymerization of isoprene.
稀土金属三（硅酰胺）配合物 LnN(SiHMe(2))(2)(THF)(x)（Ln = Sc，x = 1；Ln = Y，x = 2）与 1 当量的脒[PhC(N-2,6-R(2)C(6)H(3))(2)]H 进行胺消除反应，得到一系列中性单（酰胺基）稀土金属双（硅酰胺）配合物[PhC(N-2,6-R(2)C(6)H(3))(2)]LnN(SiHMe(2))(2)(THF)(y)（R = Me，Ln = Sc，y = 0（1）；R = Me，Ln = Y，y = 1（2）；R = (i)Pr，Ln = Y，y = 1（3））。将 1-3 与 1 当量的[Ph(3)C][B(C(6)F(5))(4)]在 THF 中处理，生成相应的阳离子酰胺基稀土金属单（硅酰胺）配合物[{PhC(N-2,6-R(2)C(6)H(3))(2)}Ln{N(SiHMe(2))(2)}(THF)(3)][B(C(6)F(5))(4)]（R = Me，Ln = Sc（4），Y（5）；R = (i)Pr，Ln = Y（6））。当 1-3 首先与 1 当量的[Ph(3)C][B(C(6)F(5))(4)]在甲苯中活化，然后用 THF 处理时，得到了意想不到的阳离子酰胺基稀土金属酰胺配合物[{PhC(N-2,6-R(2)C(6)H(3))(2)}LnN{SiHMe(2)}{SiMe(2)N(SiHMe(2))(2)}(THF)(n)][B(C(6)F(5))(4)]（R = Me，Ln = Sc，n = 2（7）；R = Me，Ln = Y，n = 4（8）；R = (i)Pr，Ln = Y，n = 2（9））。1-3 与过量 AlMe(3)反应生成镧系元素/Al 甲基配合物[PhC(N-2,6-R(2)C(6)H(3))(2)]Ln(μ-Me)(2)AlMe(2)（R = Me，Ln = Sc（10），Y（11）；R = (i)Pr，Ln = Y（12））。所有这些配合物都通过元素分析、NMR 光谱和 FT-IR 光谱得到了很好的表征。2、6 和 11 进一步通过 X 射线晶体学得到了结构确证。1/[Ph(3)C][B(C(6)F(5))(4)]的二元催化剂体系在甲苯中对异戊二烯的 3,4-选择性聚合表现出活性，而 1-3/[Ph(3)C][B(C(6)F(5))(4)]/AlMe(3)的叔催化剂体系对异戊二烯的顺式-1,4-选择性聚合具有很高的活性。
