Screening of ligands for the Ullmann synthesis of electron-rich diaryl ethers
作者:Nicola Otto、Till Opatz
DOI:10.3762/bjoc.8.122
日期:——
In the search for new ligands for the Ullmanndiaryl ether synthesis, permitting the coupling of electron-rich aryl bromides at relatively low temperatures, 56 structurally diverse multidentate ligands were screened in a model system that uses copper iodide in acetonitrile with potassium phosphate as the base. The ligands differed largely in their performance, but no privileged structural class could
Comparative study of ring-opening polymerization of <scp>l</scp>-lactide and ε-caprolactone using zirconium hexadentate bis(aminophenolate) complexes as catalysts
complexes as catalysts for the ring opening polymerization of L-lactide (LA) and ε-caprolactone (CL) were investigated. Ligands bearing various chelating groups have a profound influence on the catalysis results. Among them, the thiophen-2-yl methyl group showed the greatest activity while the pyridine-2-yl methyl group showed the worst performance with regard to the rate of CL polymerization. However
研究了一系列的双(氨基酚酸)锆配合物,用于L-丙交酯(LA)和ε-己内酯(CL)的开环聚合。带有各种螯合基团的配体对催化结果有深远的影响。其中,就CL聚合速度而言,噻吩-2-基甲基表现出最大的活性,而吡啶-2-基甲基表现出最差的性能。然而,LA聚合速率的趋势相反。动力学结果表明对[CL]和[LA]具有一阶依赖性。但是,催化剂浓度的顺序不同。聚合反应依赖于[ L OMe Zr(OBn)2CL的],但对LA的[ L OMe Zr(OBn)2 ]具有一阶依赖性。
Synthesis and in vitro antioxidant evaluation of new bis(α-aminoalkyl)phosphinic acid derivatives
GRAPHICAL ABSTRACT ABSTRACT Diamines were added to arylaldehydes in ethanol, which resulted in corresponding diimines. Novel bis-1-aminophosphinic acid compounds were synthesized through the interaction of diimines and hypophosphorous acid. The new compounds were characterized by elemental analyses, FT-IR and 1H, 13C and 31P NMR techniques. The in vitro antioxidant activity of the newly synthesized
Syntheses and Crystal Structures of Copper and Silver Complexes with New Imine Ligands − Air‐Stable, Photoluminescent Cu
<sup>I</sup>
N
<sub>4</sub>
Chromophores
作者:Goutam Kumar Patra、Israel Goldberg
DOI:10.1002/ejic.200390129
日期:2003.3
the corresponding CuI complexes [6 (2C12H12N2S2·CuClO4), 7 (2C12H12N2S2·CuClO4), and 12 (C30H27N7·CuClO4)] show quasi-reversible CuII/I couples with high redox potentials (1.001 V for 6, 0.958 V for 7, and 0.692 V for 12, vs. Ag/AgCl). This indicates that the π-acid ligands 1, 2, and 5 preferentially stabilize copper(I) over copper(II). The CuIN4 chromophores in the complexes 6, 7, and 12 display photoluminescence
g = 1.95. The dimeric [MoOCl3}2(S4)(THF)2] complex appears to be hexacoordinate and contains a bidentate sulphur bridging ligand. For both N2S and NS2 complexes, the ligands bind via the sulphur donor atoms and exhibit g = 1.94 valves in the e.s.r. spectrum. The complexes are synthesized from MoOCl3(THF)2 and the ‘fac MoOCl3’ core appears to remain intact upon complexation.
摘要配体N,N'-亚乙基双(噻吩-2-咔二胺)(N2S2)的氧钼(V)配合物;1,4,8,11-四硫代环十四烷(S4),2-巯基苯并咪唑(N2S)和2-巯基苯并噻唑(NS2)的合成和表征具有红外,可见/紫外和电子自旋共振光谱,元素分析和磁矩测量。对于[MoOCl3(N2S2)],显示该配体以二亚胺类结合,并且esr光谱显示g = 1.95。二聚体[MoOCl3} 2(S4)(THF)2]络合物似乎是六配位的,并且包含二齿硫桥联配体。对于N2S和NS2配合物,配体均通过硫供体原子结合,并在esr光谱中显示g = 1.94的阀。该复合物是由MoOCl3(THF)2合成的,“ fac MoOCl3”核心在络合后似乎保持完好无损。