Synthesis of [(dfepe)Pt(Me)(NC5F5)]+B(C6F5)4-, a highly active ethylene dimerization catalyst
Synthesis of [(dfepe)Pt(Me)(NC5F5)]+B(C6F5)4-, a highly active ethylene dimerization catalyst
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DOI：
10.1021/om8003509
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发表时间：
2008-08-11
期刊：
影响因子：
2.8
通讯作者：
Roddick, Dean M.
中科院分区：
文献类型：
--
作者：
Basu, Sayanti;Arulsamy, Navamoney;Roddick, Dean M.
本文报道了阳离子加合物（dfepe）Pt（Me）（L）（+）（dfepe =（C_2F_5）（2）PCH_2CH_2P（C_2F_5）（2）; L = MeCN，CO，C_2H_4，C_5F_5N，μ-Cl）的合成。在乙腈中用AgSbF 6处理（cod）Pt（Me）Cl，然后加入dfepe，得到（dfepe）Pt（Me）（CH 3CN）+SbF 6-。B（C-6 F5）（3）与（dfepe）Pt（Me）（O2 CCF 3）在二氯甲烷中加成，高产率地得到了结构表征的硼烷缔合产物（dfepe）Pt（Me）[（O2 CCF 3）B（C6 F5）（3）]。尝试用供体配体置换[（O2 CCF 3）B（C6 F5）（3）]（-）阴离子导致硼烷损失和（dfepe）Pt（Me）（O2 CCF 3）的再生。在环境温度下，将均三甲苯鎓酸（1，3，5-C6 H4 Me 3）B+（C6 F5）（4）（-）添加到二氯甲烷中的（dfepe）PtMe 2中，导致氯化物提取和氯化物桥接的二聚络合物[{（dfepe）Pt（Me）}（2）（mu-Cl）]B+（C6 F5）（4）（-）的沉淀，其结构已被表征。相反，在环境温度下，在五氟吡啶中用（1，3，5-C6 H4 Me 3）B+（C6 F5）（4）（-）处理（dfepe）PtMe 2导致以良好产率沉淀结构表征的五氟吡啶加合物[（dfepe）Pt（Me）（NC 5 F5）]B+（C6 F5）（4）（-）。将[（dfepe）Pt（Me）（NC 5 F5）]B+（C6 F5）（4）（-）暴露于邻二氟苯中的1个大气压CO中，得到羰基配合物[（dfepe）Pt（Me）（CO）]B+（C6 F5）（4）（-）。与先前报道的铂体系形成鲜明对比，[（dfepe）Pt（Me）（NC 5 F5）]+B（C6 F5）（4）（-）在环境温度下（600 psi乙烯，22 ℃，在邻二氟苯中，150次周转h（-1））是非常活性的乙烯二聚催化剂。乙烯加合物[（dfepe）Pt（Me）（eta（2）-C2 H4）]B+（C6 F5）（4）（-）在-20 ℃下进行了光谱表征。
The synthesis of cationic adducts (dfepe)Pt(Me)(L)(+) (dfepe = (C2F5)(2)PCH2CH2P(C2F5)(2); L = MeCN, CO, C2H4, C5F5N, mu-Cl) are reported. Treatment of (cod)Pt(Me)Cl with AgSbF6 in acetonitrile followed by the addition of dfepe afforded (dfepe)Pt(Me)(CH3CN)+SbF6-. Addition of B(C-6F5)(3) to (dfepe)Pt(Me)(O2CCF3) in methylene chloride afforded the structurally characterized borane association product (dfepe)Pt(Me)[(O2CCF3)B(C6F5)(3)] in high yield. Attempts to displace the [(O2CCF3)B(C6F5)(3)](-) anion with donor ligands resulted in loss of borane and regeneration of (dfepe)Pt(Me)(O2CCF3). Addition of the mesitylenium acid (1,3,5-C6H4Me3)B+(C6F5)(4)(-) to (dfepe)PtMe2 in methylene chloride at ambient temperatures resulted in chloride abstraction and the precipitation of the chloride-bridged dimeric complex [{(dfepe)Pt(Me)}(2)(mu-Cl)]B+(C6F5)(4)(-), which has been structurally characterized. In contrast, treatment of (dfepe)PtMe2 with (1,3,5-C6H4Me3)B+(C6F5)(4)(-) in pentafluoropyridine at ambient temperature resulted in the precipitation of the structurally characterized pentafluoropyridine adduct [(dfepe)Pt(Me)(NC5F5)]B+(C6F5)(4)(-) in good yield. Exposure of [(dfepe)Pt(Me)(NC5F5)]B+(C6F5)(4)(-) to 1 atm of CO in o-difluorobenzene gave the carbonyl complex [(dfepe)Pt(Me)(CO)]B+(C6F5)(4)(-). In marked contrast to previously reported platinum systems, [(dfepe)Pt(Me)(NC5F5)]+B(C6F5)(4)(-) is a very active ethylene dimerization catalyst at ambient temperature (600 psi ethylene, 22 degrees C in ortho-difluorobenzene, 150 turnovers h(-1)). The ethylene adduct [(dfepe)Pt(Me)(eta(2) -C2H4)]B+(C6F5)(4)(-) has been spectroscopically characterized at -20 degrees C.