节点文献
席佛碱稀土配合物的合成、结构及其反应性能研究
Synthesis, Structure and Reactivity Properties of Lanthanidecomplexes Bearing Schiff-base Ligand
【作者】 李邦玉;
【导师】 沈琪;
【作者基本信息】 苏州大学 , 有机化学, 2008, 博士
【摘要】 本论文分别采用四个席佛碱为辅助配体(3,5-But2-2-(OH)C6H2CH =N-8-C9H6N(HL1) , 3,5-But2-2(OH)-C6H2CH=N-4-R-C6H4,R=-Cl(HL2),-CH3(HL3),-F (HL4)),合成了一系列席佛碱稀土一氯化物、二氯化物及其衍生物:席佛碱基稀土茂基配合物、席佛碱基芳氧基配合物,以及均配型二齿席佛碱稀土配合物、三齿席佛碱稀土配合物、含C=N键还原偶联的稀土配合物,这些配合物都经过了包括X-光结构分析在内的全面表征。考察了席佛碱—稀土化学键在催化内酯开环聚合、苯胺与碳化二亚胺的胍化反应、异氰酸苯酯三聚反应中的反应性能,取得了以下结果:1、将席佛碱HL1与NaH按1:1摩尔比反应,得到该席佛碱的钠盐{(3,5-But2-2-(O)C6H2CH=N-8-C9H6N)Na(THF)}2 (2)。X-光结构显示该钠盐为二聚体结构,整个分子具有C2对称性。2、将原位生成的席佛碱钠盐2与LnCl3按3:1摩尔比反应,合成了下列2个均配型席佛碱稀土配合物: (3,5-But2-2-(O)C6H2CH=N-8-C9H6N)3Sm (C6H14) (6), (3,5-But2-2-(O) C6H2CH=N-8-C9H6N)3Eu(C4H8O) (C6H14) 0.5(7)。X光结构分析显示这两个配合物是同构的,中心金属为九配位。席佛碱配体HL2、HL3和HL4与分别NaH按1:1摩尔比反应,原位生成的钠盐再以3:1摩尔比与SmCl3反应,高产率地得到目标配合物(3,5-But2-2-(O)-C6H2CH=N-4-Cl-C6H4)3Sm (8)、(3,5-But2-2-(O)-C6H2CH=N-4- CH3-C6H4)3Sm(C4H8O) (C6H14)0.5(9)和(3,5-But2-2-(O)-C6H2CH=N-4-F -C6H4)3 Sm (C4H8O) (10)。对配合物8和9进行了X-Ray衍射结构分析。我们发现席佛碱—稀土金属键在较高温度下具有一定的活性,可以催化己内酯开环聚合、异氰酸苯酯环三聚反应和胺与碳化二亚胺的胍化反应。并且,席佛碱的的苯环上连接的吸电子取代基能活化席佛碱—稀土化学键。二齿席佛碱稀土配合物的活性远大于三齿席佛碱稀土配合物。3、将原位生成的席佛碱钠盐2与LnCl3按1:1的摩尔比反应,合成了下列4个席佛碱稀土二氯化物: (3,5-But2-2-(O)C6H2CH=N-8-C9H6N)YbCl2(DME)(11a) ,(3,5-But2-2-(O)C6H2CH= N-8- C9H6N)SmCl2(DME)(12),(3,5-But2-2-(O) C6H2CH =N-8- C9H6N)EuCl2(DME)(13)和(3,5-But2-2-(O) C6H2-CH=N-8-C9H6N)YCl2(DME)(14)。这些配合物都经过了元素分析、红外光谱表征,其中对配合物11a进行了X-光结构的表征。X光结构分析显示配合物11a呈溶剂化单分子结构,围绕中心金属离子的配位几何构型为扭曲的五角双锥体。席佛碱HL1的锂盐与YbCl3按1:1摩尔比反应,合成了离子对型席佛碱镱二氯化物((3,5-But2-2-(O)C6H2CH= N-8- C9H6N)YbCl3)(Li(DME)3(11b)。配合物经过了元素分析、红外光谱和X-光结构分析的表征,X-光结构显示中心金属镱为六配位,阴离子的配位几何构型是扭曲的八面体。4、席佛碱稀土二氯化物(3,5-But2-2-(O)C6H2CH=N-8-C9H6N)LnCl2(DME)(Ln =Yb(11a), Sm (12), Eu(13), Y(14))与NaCH3C5H4按1:1摩尔比反应,分离到了含一个席佛碱基和甲基环戊二烯基稀土氯化物(3,5-But2-2-(O)C6H2CH=N-8-C9H6N) LnCl(CH3C5H4)(THF)(Ln = Yb(15), Sm (16), Eu(17), Y(18))。配合物经过了全面表征,其中Yb(15), Sm (16), Eu(17)的配合物经过了X-光结构鉴定。配合物11a与Na(OC6H3-But2-2,6)按1:2摩尔比反应得到(3,5-But2-2-(O)C6H2CH=N-8- C9H6N)Yb(OC6H3-But2-2,6)2(19),而Yb(OC6H3-But2-2,6)3与席佛碱HL1按1:1摩尔比反应也得到了相同的配合物。上述配合物经过了全面表征,X-光结构分析显示配合外物19中Yb离子为不多见的五配位,呈三角双锥几何构型。5、席佛碱钠盐2与LnCl3按2:1的摩尔比反应,合成了下列3个席佛碱稀土一氯化物: (3,5-But2-2-(O)C6H2CH=N-8-C9H6N)2LnCl(THF) 3.5 (Ln =Yb(20), Sm (21), Eu(22)),这些配合物都经过了元素分析、红外光谱表征,其中配合物20进行了X-光结构的表征。配合物20与Na(OC6H3-But-2-Me-4)以1:1的摩尔比反应,得到了配合物(3,5-But2-2-(O)C6H2CH=N-8-C9H6N)2Yb(OC6H3-But-2-Me-4) (THF)2.5 (23)。X-光结构分析表明,中心稀土离子的配位几何构型可以描述成五角双锥型,其中芳氧和一个席佛碱中的氧原子占据两个锥顶点。配合物20与(CH2=CH-CH2)MgBr以1:1的摩尔比反应,分离到了[Mg(H2N-8-C9H6N)Cl(THF)3]Br(24)。6、席佛碱HL1、LiBu、YbCl3和Na(OC6H3-But-2-Me-4)按2:2:1:1的摩尔比反应,合成了一个经历正丁基锂加成一个C=N双键过程的席佛碱镱芳氧化物:(3,5-But2-2-(O)C6H2CH=N-8-C9H6N)(3,5-But2-2-(O)C6H2CH(C4H9)--NH-8-C9H6N) Yb (OC6H3-But-2- Me-4) (C7H8)2.5 (25)。配合物经过了元素分析、红外光谱和X-光结构分析表征。7、Yb[N(TMS)]3与席佛碱HL1按1:3摩尔比反应得到均配型席佛碱配合物(3,5-But2-2-(O)C6H2CH=N-8-C9H6N)3Yb(C4H8O)4(26),而按1:1摩尔比反应得到了由两个席佛碱偶联的配合物YbL1``2 (28)(L1``2 3-为两个席佛碱通过一个C-C键偶联起来的三负离子)。8、我们试图合成席佛碱二价稀土配合物,用Yb(II)[N(TMS)]2与席佛碱HL1按1:3摩尔比在40度反应,却得到均配型三价席佛碱配合物(3,5-But2-2- (O)C6H2CH=N-8-C9H6N)3Yb(C4H8O)4 (26)。配合物经过全面表征。用席佛碱Sm一氯化物21与过量的钠在40度下反应,也没有得到通常的席佛碱二价Sm配合物,而是分离到了一个由三个配体HL1偶联后形成的结构新颖的产物[Na(DME)3] [SmL1`3Na(DME)] (27)(L1`35-为三个席佛碱通过两个C-C键偶联起来的带五个单位负电荷的阴离子) ,配合物经过了元素分析、红外光谱和X-光结构测定。
【Abstract】 A series of lanthanide dichloride, chloride, aryloxide and methylcyclopentadienyl complexes supported by bidentate or tridentate Schiff base ligand [( 3,5-But2-2-(OH) C6H2CH=N-8-C9H6N(HL1), 3,5-But2-2(OH)-C6H2CH=N-4-R-C6H4, R= -Cl (HL2), -CH3 (HL3), -F (HL4)] were synthesized and well characterized, including monometallic dichloride, chloride, aryloxide and methyl-cyclopentadienyl, as well as a ytterbium and samarium complexes bearing an unprecedented dimeric or trimeric polyanionic ancillary ligands. The catalytic activity of these complexes in polymerization ofε-caprolactone, guanylation of amines with carbodiimides and cyclotrimerization of phenyl isocyanat respectively was tested. The main results obtained are as follows:1. The treatment of salicylaldimine 3,5-But2-2-(OH)C6H2CH=N-8-C9H6N (HL1) and NaH in 1:1 mole ratio in THF yielded the sodium salt of salicylaldimine {(3,5-But2-2-(O) C6H2CH=N-8-C9H6N) Na(THF)}2 (2) in good yield. The complex was characterized by elemental analysis, 1HNMR spectroscopy and X-ray diffraction. The crystal structural analysis of (2) revealed that it had a dimeric structure .2. The in situ generated 2 from the treatment of the mixture of NaH with 1 equiv HL1 in THF reacts with 1/3 equiv of LnCl3 (Ln = Sm, Eu) to give the monomeric lanthanide Schiff base complexes (3,5-But2-2-(O)C6H2CH=N-8- C9H6N)3Sm (C6H14) (6) and (3,5-But2-2-(O) C6H2CH= N-8-C9H6N)3 Eu(C4H8O) (C6H14) 0.5(7) in good yield, respectively. The X-ray diffraction analysis showed that the atoms of Sm and Eu were nine-coordinate. The in situ generated [3,5-But2-2 (OH)-C6H2CH=N-4-R-C6H4]Na (R= -Cl (HL2), -CH3 (HL3), -F (HL4) from the treatment of the mixture of NaH with 1 equiv 3,5-But2-2(OH)-C6H2CH=N-4-R-C6H4 (R= -Cl (HL2),-CH3 (HL3),-F (HL4) in THF reactions with 1/3 equiv. of SmCl3 to give the monomeric samarium Schiff base complexes(3,5-But2-2-(O)-C6H2CH= N-4-Cl-C6H4)3Sm(C4H8O) (8),(3,5-But2-2-(O)-C6H2CH =N-4- CH3-C6H4)3Sm (C6H14) 0.5 (9), (3,5-But2-2-(O)-C6H2CH =N-4-F-C6H4)3Sm(C4H8O) (10), respectively. The complexes 8 and 9 were determined by X-ray diffraction. These complexes can catalyze the polymerization ofε-caprolactone, guanylation of amines. The electron-withdrawing group on the Schiff base ligand can increase the activity of samarium complexes: the active sequence is Cl > F > CH3. Bidentate Schiff base complexes exhibited much higher reactivity than the tridentate Schiff base complexes.3. The in situ generated 2 from the treatment of the mixture of NaH with 1 equiv HL1 in THF reacts with 1 equiv. of LnCl3 (Ln =Yb, Sm, Eu, Y) to give the lanthanide Schiff base dichloride complexes (3,5-But2-2-(O) C6H2CH=N-8-C9H6N)YbCl2(DME) (11a), (3,5-But2-2-(O) C6H2CH= N-8- C9H6N)SmCl2(DME) (12), (3,5-But2-2-(O) C6H2CH=N-8-C9H6N)EuCl2(DME)(13) and (3,5-But2-2 -(O) C6H2-CH=N-8-C9H6N) YCl2(DME)(14), respectively. The complex 11a was determined by X-ray diffraction. The crystal structure revealed the Complex 11a had a solvated monomeric structure, and the central metal ytterbium atom was seven-coordinated. In contrast, a complex ((3,5-But2-2-(O)C6H2CH= N-8-C9H6N)YbCl3)(Li(DME)3(11b) was prepared when lithium salt from the treatment of the mixture of LiBu with 1 equiv. HL1 in THF was used instead of the sodium salt of HL1 . In anion, the central metal Yb was six-coordinated.4. Reaction of 11a, 12, 13 and 14 with NaCH3C5H4 in 1:1 molar ratio, respectively, gave the complexes (3,5-But2-2-(O)C6H2CH=N-8-C9H6N)LnCl (CH3C5H4)(THF)(Ln =Yb(15), Sm (16), Eu(17), Y(18)). The complexes 15, 16, and 17 had been characterized by X-ray diffraction. The structural analysis showed that three complex had isostructural complexes. Reaction of complex 11a with 2 equiv. of Na(OC6H3-But2-2,6) in THF afforded the desired solvent-free ytterbium aryloxide [(3,5-But2-2-(O)C6H2CH= N-8-C9H6N)Yb(OC6H3-But2-2,6)2] (19). Complex 19 can also be prepared by the protolytic exchange reaction of HL1 with (OC6H3-But2-2,6)3Yb in 1:1 molar ratio. The structural analysis showed Yb atoms was five-coordinated distorted trigonal bipyramidal geometry.5. The in situ generated 2 from the treatment of the mixture of NaH with 1 equiv 3 in THF reacts with 1 equiv. of LnCl3 (Ln =Yb, Sm, Eu) to give the lanthanide Schiff base chloride complexes {(3,5-But2-2-(O)C6H2CH=N-8-C9H6N)}2LnCl(C4H8O) 3.5 (Ln =Yb(20), Sm(21), Eu(22)), respectively. The complex 20 was determined by X-ray diffraction. Reaction of complex 20 with 1 equiv. of Na(OC6H3-But-2-Me-4) in THF afforded the desired ytterbium aryloxide [(3,5-But2-2-(O)C6H2CH= N-8-C9H6N ) 2Yb(OC6H3-But2-2,6) (THF) 2.5 (21). The structural analysis showed that the coordination geometry around ytterbium atom can be described as a distorted pentagonal bipyramid. Reaction of complex 20 with 1 equiv. of (CH2=CH-CH2)MgBr in THF afforded the [Mg(H2N -8-C9H6N) Cl(THF)3]Br (24).6. Reaction of the Schiff base HL1, LiBun, YbCl3 and Na(OC6H3-But-2-Me-4) in 2:2:1:1 molar ratio afforded an unprecedented ytterbium aryloxide (3,5-But2-2-(O) C6H2CH =N-8-C9H6N) (3,5-But2-2-(O) C6H2CH(C4H9) -NH-8-C9H6N)Yb (OC6H3-But-2 -Me-4)(C7H8)2.5 (25). Complex was fully characterized by elemental analysis and X-ray diffraction.7. The reaction of Yb[N(TMS)]3 with Schiff base HL1 in 1:3 molar ratio afforded the Schiff base ytterbium (III) complex (3,5-But2-2-(O)C6H2CH= N-8-C9H6N)3Yb(C4H8O)4 (26). However, reaction of Yb[N(TMS)]3 with HL1 in 1:1 molar ratio afforded an unprecedented ytterbium (III) complex YbL1``2(28), in which two Schiff base HL1 were dimerized to form the new ligand H3L1``2 by the reductive coupling reactions of imine groups involving a rare coupling reaction of C=N bond of quinoline ring with imine group of Schiff base ligand.8. The reaction of Yb(II)[N(TMS)]2 with Schiff base HL1 in 1:3 molar ratio also afforded the Schiff base ytterbium (III) complex (26). Treatment of complex 21 with excessive metallic sodium produced an unprecedented samarium complex [Na(DME)3][SmL1`3Na(DME)] (27), in which three Schiff base HL1 were trimerized to form the new ligand H5L1`3 by the reductive coupling reactions of imine groups also involving a rare coupling reaction of C=N bond of quinoline ring with imine group of Schiff base ligand.
【Key words】 Schiff base; lanthanide complexes; synthesis; structure; reactivity properties;