【作者】 王俊峰；

【导师】 沈琪；

【作者基本信息】 苏州大学 ， 有机化学， 2008， 博士

【摘要】 本文以桥联脒基为配体（L = [Me₃SiNC（Ph）N（CH₂）₃NC（Ph）NSiMe₃] ）,合成了一系列桥联脒基双金属及阴离子型稀土配合物,桥联脒基茂基、烷氧基、胺基稀土配合物及桥联脒基稀土（Ⅱ）配合物,这些配合物都经过了包括X-光结构分析在内的全面表征。考察了它们在催化内酯开环聚合、胺与碳化二亚胺的胍化反应、胺与腈的脒化反应以及醛与胺的酰化反应中的催化活性。主要研究结果如下:1将桥联脒基锂盐LLi₂与LnCl₃按1:1摩尔比反应得到了3个桥联脒基稀土氯化物LYb（μ-Cl）₂Yb（THF） （3-1）, LYbCl（THF）₂ （3-2）和LYCl（DME） （3-3）。所有配合物都经过X-ray单晶衍射、红外光谱、元素分析表征。测定了3-3的1H NMR。2考察了稀土氯化物的稳定性。氯化物与1当量的HOiPr反应,可使配体中的一个脒基水解,成为中性脒,从而得到相应的脒基功能化的脒基稀土配合物[L′（H₂）]2YbCl （3-4）和[L′（H₂）]2NdCl （3-5） （L′（H₂） = [Me₃SiNHC（Ph）N（CH₂）3NC（Ph）NHSiMe₃]）。这两个配合物具有相同的固态分子结构。围绕中心金属的配位几何构型为扭曲的五角双锥。通过配体的定量水解是合成脒基功能化的脒基稀土配合物的一条方便的新路线。3考察了稀土氯化物的反应性。将桥联脒基稀土氯化物3-2与1当量的NaCp反应可得到单金属的茂金属配合物LYbCp（DME） （3-6）;将LLi₂与2当量的Cp2YbCl反应得到了双金属的茂金属配合物CpYbLYbCp （3-7）。这一结果表明该桥联配体既可以作为螯合配体与一个金属配位,也可作为桥配体同时与两个金属配位。4将桥联脒基稀土氯化物3-2和3-3分别与0.5当量的桥联脒基双锂盐LLi₂反应得到了经配体再分配的双金属配合物Yb（μ-L）₃Yb （3-8）和Y（μ-L）₃Y （3-9）, 3-8和3-9也可通过LLi₂与LnCl₃以3:2摩尔比反应得到。LLi₂与LnCl₃以2:1摩尔比反应可高产率地得到阴离子型桥联脒基稀土配合物[Li（DME）₃][L₂Ln] （Ln = Yb 3-10, Y= 3-11, Nd 3-12, Eu 3-13）。这些配合物都经过了包括X-ray单晶衍射在内的全面表征。5桥联脒基双金属产物3-8和3-9以及阴离子型配合物[Li（DME）₃][L₂Ln] （Ln = Yb 3-10, Y= 3-11, Nd 3-12, Eu 3-13）都可以催化己内酯的开环聚合,双金属配合物的活性高于相应阴离子型配合物,中心金属对活性有很大影响,活性顺序是Nd > Eu > Y > Yb,这些体系的可控性都不好。此外,它们还都可以催化胺与碳化二亚胺的胍化反应以及醛与胺的酰胺化反应,阴离子型配合物的活性明显高于双金属配合物的活性。6选用了三个具有不同空间效应的胺基-NHAr′（Ar′= 2,6-Me₂C₆H₃）、-NHAr （Ar = 2,6-ⁱPr₂C₆H₃）和-N（SiMe₃）₂,考察了胺基结构对桥联脒基镱的胺化物的结构及催化行为的影响。当稀土氯化物3-2与体积相对较小的NaNHAr′（Ar′NH = 2,6-Me₂C₆H₃NH）和NaNHAr （ArNH = 2,6-iPr2C6H3NH）反应时,分别得到单金属胺化物LYb（NHAr′）（DME） （4-1）和LYb（NHAr）（DME） （4-2）;当与位阻更大的胺基钠NaN（SiMe₃）₂反应时,则得到了经配体再分配的双金属胺化物（TMS）₂NYb（L）₂YbN（TMS）₂ （4-3）。这些胺化物都可以催化己内酯和丙交酯的开环聚合,单金属胺化物比双金属胺化物显示更好的活性与可控性。首次发现上述桥联脒基稀土胺化物可以催化胺与腈的反应选择性地生成单取代脒。7中性胺化物LYb（NHAr）（DME） （4-2）与1当量的LiNHAr （ArNH= 2,6-iPr₂C₆H₃NH）反应得到了经X-ray单晶衍射证明的阴离子型胺化物[Li（DME）₃][LYb（NHAr）₂] （4-4） ,并发现阴离子型胺化物在催化胺与碳化二亚胺的胍化反应中的活性明显高于中性胺化物的活性。8稀土卤化物LYbCl（THF）₂ （3-2）分别与当量的芳氧钠盐NaOAr′（Ar′O = 2,6-iPr₂C₆H₃O）反应,得到了单金属配合物LYb（OAr）（DME） （5-1）;与当量的异丙氧基钠NaOiPr反应,则得到了经配体再分配的双金属配合物Yb（L）₂（μ2-OⁱPr）₂Yb （5-2）。这两个配合物都经过了全面的表征。它们都能催化丙交酯和己内酯的可控开环聚合。首次发现这些稀土烷氧配合物可以催化胺与碳化二亚胺的胍化反应。9首次提出了通过n-BuLi控制水解的方法合理地合成了由Li₂O和LiI构建的二价稀土簇合物6-1。将桥脒锂盐LLi₂和YbI₂按1:2摩尔比反应合成了第一个双金属二价稀土卤化物IYbLYbI （6-2）。这两个二价稀土配合物都可以催化胺与碳化二亚胺的胍化反应、胺与腈的脒化反应。簇合物6-1的活性明显高于6-2的活性。更多还原

【Abstract】 A series of lanthanide bimetallic, anionic, alkoxide, amido complexes and lanthanide divalent complexes supported by linked bis（amidinate）s （L = [Me₃SiNC（Ph）N（CH₂）₃NC（Ph）NSiMe₃] ） were synthesized and well characterized, including monometallic and bimetallic alkoxides, amides, cyclopentadieyl and amidinate, and anionic amidinates and amides, as well as a divalent ytterbium cluster and a bimetallic amidinate ytterbium iodide. The catalytic activity of these complexes in polymerization ofε-caprolactone and lactide, guanylation of amines with carbodiimides, amination of amines with nitriles and acylation of aldehydes with amines, respectively, was tested. The main results obtained are as follows:1 Reaction of dilithium bis（amidenate）s LLi₂ with LnCl₃ in 1:1 moral ratio afforded the three bis（amidinate）s chlorides LYb（μ2-Cl）₂Yb（THF） （3-1）, LYbCl（THF）₂ （3-2） and LYCl（DME） （3-3）. All these complexes were well characterized including X-ray diffraction, IR spectroscopy, elemental analysis and 1H NMR for 3-3.2 Reaction of bis（amidinate）s lanthanide chlorides with equimolar of HOiPr was examined. Complexes of [L′（H₂）]₂YbCl （3-4） and [L′（H₂）]₂NdCl （3-5） （L′（H₂） = [Me₃SiNHC（Ph）N（CH₂）₃NC（Ph）NHSiMe₃]） were isolated via the hydrolysis of one of amidinatos by HOiPr. The quantitative hydrolysis of a bridged bis（amidinate）s was proved to be a convenient route to an amidine-functionalized amidenate lanthanide complex. X-ray analysis showed the coordination geometries around the center metals in the two complexes were described as a distorted pentagonal bipyramid.3 Reaction of ytterbium chloride 3-2 with equimolar of NaCp afforded the corresponding monometallic cyclopentadienyl complex LYbCp（DME） （3-6）, while reaction of bis（amidenate）s dilithium LLi₂ with two equiv of Cp₂YbCl yielded the bimetallic complex CpYbLYbCp （3-7）. The results indicated that the ligand can act as a chelated ligand to coordinate to one metal or as a bridged ligand to bind to two metals depending on the reagents used.4 Reaction of ytterbium chloride 3-2 and 3-3 with 0.5 equiv of LLi₂, respectively, afforded the corresponding bimetallic complexes Yb（μ-L）₃Yb （3-8） and Y（μ-L）3Y （3-9） formed through the rearrangement reaction of L. Complexes 3-8 and 3-9 can also be synthesized by the reaction of LnCl₃ （Ln = Yb, Y） with 1.5 equiv of Li₂L. Reaction of LnCl₃ with 2 equiv of Li₂L gave the anionic complexes [Li（DME）3][L2Ln] （Ln = Yb 3-10, Y= 3-11, Nd 3-12, Eu 3-13）. All the complexes were characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction.5 Bimetallic complexes 3-8 and 3-9 and the anionic complexes [Li（DME）₃][L₂Ln] （Ln = Yb 3-10, Y= 3-11, Nd 3-12, Eu 3-13） can catalyze the polymerization ofε-caprolactone, however, bimetallic complexes exhibit much higher reactivity than the anionic complexes. Center metal has a profound effect on the reactivity: the active sequence is Nd > Eu > Y > Yb. All systems showed poor controllability. Moreover, all complexes can catalyze guanylation of amines with carbodiimides and acylation of aldehydes with amines. The anionic complex showed much higher reactivity in comparison with the bimetallic complexes in both reactions.6 The molecular structures and reactivity of bis（amidinate）s ytterbium complexes with varied amides were investigated. Reaction of LYbCl（THF）₂ with equimolar NaNHAr′（Ar′NH = 2,6-Me₂C₆H₃NH） and NaNHAr （ArNH = 2,6-iPr₂C₆H₃NH）, respectively, gave the corresponding monometallic amide complexes LYb（NHAr′）（DME） （4-1） and LYb（NHAr）（DME） （4-2）, in which the linked bis（amidinate）s coordinate to the center metal as a chelating ligand. The same reaction with NaN（SiMe₃）₂ afforded the bimetallic amide complex （TMS）₂NYb（L）₂YbN（TMS）₂ （4-3） formed through the rearangement reaction of L induced by the bulky N（SiMe₃）₂ group. In complex 4-3 the two linked bis（amidinate）s act as bridging ligands to link two species of YbN（TMS）₂ in one molecule. All these amides are efficient initiators for polymerization ofε-caprolactone and L-lactide. The catalytic performance is substantially different between the two kinds of amides. The polymerizations initiated by complexes 4-1 and 4-2 proceeded in a living fashion as evidenced by the resulting polymers with narrow polydispersities, together with the linear natures of number average molecular weight versus conversion plots, while the polymerization system with complex 4-3 provided the polymers with rather broad molecular weight distributions. Moreover, these amides can catalyze the amination of amines with nitriles, complexes 4-1 and 4-2 show higher activity and better selectivity than 4-3.7 Reaction of 4-2 with equimolar LiNHAr （ArNH= 2,6-iPr₂C₆H₃NH） afforded the anionic amide [Li（DME）₃][LYb（NHAr）₂] （4-4）, which was characterized by X-ray determination. Both complexes can catalyze guanylation of amines with carbodiimides, and the anionic complexes exhibit much higher reactivity than the corrsponding neutral amides.8 The influence of alkoxyl groups on molecular structures and reactivity of ytterbium alkoxide complexes supported by linked bis（amidinate）s L was investigated. Reaction of LYbCl（THF）₂ （3-2） with equimolar NaOAr （Ar = 2,6-iPr₂C₆H₃O） gave the monometallic aryloxide complex LYb（OAr）（DME） （5-1）, while the same reaction with NaOiPr afforded the bimetallic alkoxide complex with two alkoxy-bridges Yb（L）₂（μ2-OiPr）₂Yb （5-2）, which was prepared through the redistribution reaction of L occurred concomitantly during the metathesis reaction as the encapsulation of two OiPr bridges. In complex 5-2 the linked bis（amidinate）s acts as bridging ligands. The definite molecular structures of 5-1 and 5-2 were provided by a single-crystal X-ray analysis. Both of the complexes can initiate the polymerization of cyclic ester in a living fashion as evidenced by the resulting polymers with narrow molecular weight distributions, together with the linear natures of number average molecular weight versus conversion plots. Complexes 5-1 and 5-2 can catalyze guanylation of amines with carbodiimides, and 5-2 is more active.9 A novel divalent bis（amidinete）s ytterbium cluster 6-1 constructed by Li₂O and LiI was synthesized rationally via introduce of quantitative Li₂O formed by hydrolysis of n-LiBu with H₂O. The first divalent bimetallic ytterbium halide complex IYbLYbI （6-2） was synthesized by reaction of LLi2 with YbI2 in the moral ratio of 1:2. The further study indicated that both of the complexes can catalyze guanylation of amines with carbodiimides and amination of amines with nitriles, and cluster 6-1 exhibits much higher reactivity in comparison with the bimetallic complex 6-2.更多还原