【作者】 许崇杰；

【导师】 沈琪； 唐勇；

【作者基本信息】 苏州大学 ， 有机化学， 2012， 博士

【摘要】 本论文设计、合成了一系列镍配合物和钛配合物,并在此基础上研究了配合物结构对烯烃聚合活性及选择性的影响。主要内容包括以下三部分：论文第一部分,设计并合成了14个含β-酮亚胺阴离子配体的苯基镍配合物110-123。除了核磁,元素及红外表征,还对配合物116、122和123进行了X-Ray单晶衍射表征。配合物单晶结构表明,当边臂杂原子为硫原子或氮原子时,边臂杂原子直接与镍配位形成扭曲的平面四边形构型；相反,当有桥联苯基或者边臂杂原子为氧原子时,中心金属镍并不是与边臂杂原子配位,而是与PPh3配位形成扭曲的平面四边形构型。通过对上述一系列配合物的高压乙烯聚合尝试,发现在MAO作为助催化剂的条件下,催化聚合产物以丁烯为主,且1-丁烯的选择性最高可达90.2%,聚合活性最高可达9.35×106g/molNi·atm·h,为目前文献报道最高值；通过优化条件,己烯和辛烯含量最高可达14.7%。此外,通过对催化剂结构的进一步筛选可以看出,边臂杂原子对α-烯烃选择性具有非常显著的影响。论文第二部分,合成了8个含β-二亚胺阴离子配体的溴化镍配合物133-140和含中性β-二亚胺配体的二溴化镍配合物171。通过对它们的X-Ray单晶衍射表征可以看出,当配合物含氮边臂或者硫边臂时,其配合物构型为扭曲的平面四边形；当含有氧边臂或者没有边臂时,两分子配合物彼此螯合形成扭曲的三角锥构型。常压乙烯聚合尝试发现,这类配合物不能催化乙烯聚合。将上述β-二亚胺溴化镍配合物与氧气反应,并通过对配合物141的X-Ray单晶衍射,最终确定得到了一类结构新颖的双金属自氧化配合物141-146。在助催化剂MMAO的作用下,这类双金属配合物即使在常压下也能以很高的活性(>105g/molNi·h·atm)催化乙烯聚合。通过对配合物结构的进一步优化,最高活性可达到1.0×106g/molNi·atm·h。论文的第三部分,设计并合成了一类2,6位二取代酚基的钛配合物151-159。配合物151和154的单晶表征表明这类双边臂配合物中的边臂杂原子并没有与中心金属钛发生配位。在助催化剂MMAO作用下,即使在高温(>100℃)、长聚合时间(≥1hrs)等条件下,这类催化剂仍能保持较高的活性(105g sPS/molTi·h)及很高的间规度(>99%)。更多还原

【Abstract】 In this thesis, a series of nickel complexes and titanium complexes were designed and synthesized. Based on these complexes, we studied the relationship between catalyst structure and catalytic activity and selectivity in olefin polymerization.Part Ⅰ, a series of β-ketoimine-derived nickel(Ⅱ) complexes have been synthesized and characterized by NMR, element analysis and IR. The X-ray structure of116,122and123also had been studied. The single crystal structures show that the heteroatom on the side-arm was coordinated to nickel except the oxygen atom on the side-arm and bridged-phenyl. When activation by MAO, these complexes promote the polymerization of ethylene very smothly and the main products are butenes, in which the highest selectivtity of1-butene reached90.2%with up to9.35×106g/molNi·h·atm. Under optimized the polymerization condition, the highest selectivtity of both hexenes and octenes reached14.7%.Part Ⅱ, we syntheis a series of nickel(Ⅱ) complexes bearing β-diimine anion and neutral β-diimine ligand. The X-ray structures of those nickel complexes show that central nickel adopts distorted square planar geometry when sulfur atom is on the side-arm, but the distorted tetrahedron has been adopted in the presence of oxygen sidearm or absence of sidearm. Unfortunately, those β-diimine nickel complexes are inactive in ethylene polymerization.These complexes proned to be oxygenated by oxygen and give new di-nickel(Ⅱ) complexes have been obtained. Of these complexes,141has been confirmed by X-ray single crystal diffraction. In the presence of MMAO, those dinickel complexes show high activity (>105g/molNi·h·atm) under atmospheric pressure. Under optimal conditions, the activity can reach1.0×106g/molNi·h·atm.Part Ⅲ, a series of2,6-disubstituented-4-methylphenolate titanium(Ⅳ) complexes have been synthesized. Upon treatment with MMAO, those non-cyclopentadienyl Ti(Ⅳ) complexes succesfully catalyze styrene bulk polymerization even at higher temperture and long time, showing modest activity(105g sPS/molTi·h) and high syndiotacticity(>99%).更多还原