Hydrogen-bond-supported dimeric boron complexes of potentially tetradentate β-diketiminate ligands
作者:Stephanie M. Barbon、Viktor N. Staroverov、Paul D. Boyle、Joe B. Gilroy
DOI:10.1039/c3dt52188e
日期:——
demethylation of β-diketimine ligands and boron difluoride complexes bearing 2-anisole N-aryl substituents using boron tribromide. The resulting complexes were found to contain a unique hydrogen-bond-supported boron–oxygen–boron bridge, as confirmed by X-ray crystallography. The stability of the resulting dimeric structures relative to the corresponding monomeric, tetradentate boron complexes was studied computationally
pentamethylcyclopentadienyl (Cp*) metalcomplexes (η5-C5Me4R)ZrCl2LCO (R = H(1), Me(2)) and (η5-C5Me4R)HfCl2LCO (R = H(3), Me(4)) where LCO is a bifunctional β-diketiminate ligand [2-(MeO)–C6H4)]NC(Me)CHC(Me)N[2-(MeO)–C6H4)] (LCO) were prepared from corresponding tetramethyl- and (pentamethylcyclopentadienyl)metal trichlorides and the lithium precursor LiLCO. All complexes were characterized by their melting
一系列四甲基(CP')和五甲基环戊二烯(CP *)金属络合物(η的5 -C 5我4 R)的ZrCl 2大号CO(R = H(1)中,Me(2))和(η 5 -C 5 Me 4 R)HfCl 2 L CO(R = H(3),Me(4)),其中L CO是双功能β-二酮基配体[2-(MeO)-C 6 H 4)] NC(Me)CHC (Me)N [2-(MeO)-C 6 H 4)](L CO由相应的四甲基和(五甲基环戊二烯基)金属三氯化物和锂前体LiL CO制备)。所有配合物的特征在于它们的熔点,元素分析,1 H和13 C NMR光谱,IR光谱。另外,它们的固态结构通过X射线衍射技术确定。在所有情况下,与环戊二烯基配在顶部金属中心的伪四方锥体配位环境和螯合升近isobidentately键合氮原子的CO配体在一个开放的η 5-观察到时尚。位于二酮化外围的氧原子在固相和溶液中均不与过渡金属配位。 除
Polar‐Group Activated Isospecific Coordination Polymerization of
<i>ortho</i>
‐Methoxystyrene: Effects of Central Metals and Ligands
作者:Yunjie Chai、Lingfang Wang、Dongtao Liu、Zichuan Wang、Mingtao Run、Dongmei Cui
DOI:10.1002/chem.201805012
日期:2019.2.6
Stereoselective polymerization of polar vinyl monomers has been a long‐standing challenge because the employed transition‐metalcatalysts are easily poisoned by polar groups of monomers. In this contribution, a series of β‐diketiminato rare‐earthmetal complexes 1–5 (L1–5Ln(CH2SiMe3)2(THF)n, Ln=Gd–Lu, Y, and Sc) were successfully synthesized. In combination with AliBu3 and [Ph3C][B(C6F5)4], complexes
极性乙烯基单体的立体选择聚合一直是一个长期的挑战,因为所使用的过渡金属催化剂容易被单体的极性基团中毒。在此贡献中,一系列的β -diketiminato稀土类金属络合物1 - 5(L 1-5 LN(CH 2森达3)2(THF)Ñ,Ln为钆路,Y,和Sc)被成功地合成。与Al i Bu 3和[Ph 3 C] [B(C 6 F 5)4 ]结合使用,络合物1 c(Tb)– 1 g(Tm)为显示出高的活性和优良的对于isoselectivities的聚合邻-methoxystyrene(Ô MOS),其中,的极性甲氧基ö MOS没毒但与活化通过σ-π螯合聚合以活性种一起乙烯基。而且,大的Gd-附着前体1 b表现出较高的活性,虽然具有略微降低isoselectivity。带有Sc的小型前驱物1 i完全是惰性的。同时,β-二酮基氨基配体的空间空间排列和配位模式可以明显影响甚至阻断o。MOS聚合
Structure and potential applications of amido lanthanide complexes chelated by bifunctional β-diketiminate ligand
The synthesis and structure of lanthanide(III) amides containing one bifunctional β-diketiminate ligand is reported. Compounds were obtained via a protolytic reaction of the free β-diketimine N-[(2-MeO)C6H5]}NC(Me)CHC(Me)N(H)N′-[(2-MeO)C6H5]} (LCOH) or N-[(2-MeO)C6H5]}NCHCHCHN(H)N′-[(2-MeO)C6H5]} (LHOH) with corresponding tris(amide) of the Ln[N(SiMe3)2]3 (Ln = Y, La, Nd, Sm, Eu, Gd and Yb) type
报道了含有一种双功能β-二酮基配体的镧系元素(III)酰胺的合成和结构。化合物通过游离β-二酮亚胺 N -[(2-MeO)C 6 H 5 ]} N C(Me)CH C(Me)N(H) N '-[(2- MeO)C 6 H 5 ]}(L CO H)或 N -[(2-MeO)C 6 H 5 ]} N CHCH CHN(H) N '-[(2-MeO)C 6 H 5 ] }(L HOH)与相应的Ln [N(SiMe 3)2 ] 3(Ln = Y,La,Nd,Sm,Eu,Gd和Yb)型三(酰胺)型在环境温度下成摩尔比。通过IR和/或多核NMR光谱技术表征产物,并且已经通过X射线衍射技术确定了其中四种的结构。配合物L CO Y [N(SiMe 3)2 ] 2,L CO La [N(SiMe 3)2 ] 2,L CO Nd [N(SiMe 3)2 ] 2和L HO Yb [N(SiMe 3)2]
Achiral Lanthanide Alkyl Complexes Bearing N,O Multidentate Ligands. Synthesis and Catalysis of Highly Heteroselective Ring-Opening Polymerization of <i>rac</i>-Lactide
found for complex 4. The Salan yttriumalkylcomplex 6 was active but nonselective. Bis(alkyl) complexes 7 and 8 were more active than 1−3 toward polymerization of rac-LA, however, to afford atactic polylactides due to di-active sites. The ligand framework, especially the “bridge” between the two nitrogen atoms, played a significant role in governing the selectivity of the corresponding complexes via changing
氨基-氨基-双(酚)H 2 L 1的烷烃消除反应- 4,萨兰H 2 L 5和甲氧基-β-二亚胺HL 6,7用镧系元素的三(烷基)类,LN(CH 2森达3)3(THF)2(Ln为Y,Lu)中,分别得到了一系列的镧系元素络合物烷基1 - 8以四甲基硅烷的释放。配合物1 - 6是THF溶剂化的单(烷基)S按稳定的O,N,N,O -tetradentate配体。配合物1 - 3和5采用扭曲的八面体几何形状,而4包含四方双锥芯。带有单阴离子部分L 6(L 7),配合物7(8)是不含THF的双(烷基)。在配合物7中,O,N,N-三齿配体与两个烷基物质结合形成四面体配位核心。配合物1,2,和3显示适度的活性,但是高立体选择性为聚合外消旋-丙交酯,得到聚乳酸杂同与单体单元的外消旋enchainment P ř范围从0.95至0.99,达到迄今的最高值。复杂5表现出几乎相同的活性水平,尽管选择性相对较低。相