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61.
Dr. Josh Abbenseth Dr. Florian Wätjen Dr. Markus Finger Prof. Dr. Sven Schneider 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(52):23780-23784
The utilization of monomeric, lower phosphorous oxides and oxoanions, such as metaphosphite (PO2−), which is the heavier homologue of the common nitrite anion but previously only observed in the gas phase and by matrix isolation, requires new synthetic strategies. Herein, a series of rhenium(I–III) complexes with PO2− as ligand is reported. Synthetic access was enabled by selective oxygenation of a terminal phosphide complex. Spectroscopic and computational examination revealed slightly stronger σ-donor and comparable π-acceptor properties of PO2− compared to homologous NO2−, which is one of the archetypal ligands in coordination chemistry. 相似文献
62.
In this work, a vanillin complex is immobilized onto MCM-41 and characterized by FT-IR, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, thermogravimetric analysis, and BET techniques. This supported Schiff base complex was found to be an efficient and recoverable catalyst for the chemoselective oxidation of sulfides into sulfoxides and thiols into their corresponding disulfides (using hydrogen peroxide as a green oxidant) and also a suitable catalyst for the preparation of 2,3-dihydroquinazolin-4(1H)-one derivatives in water at 90°C. Using this protocol, we show that a variety of disulfides, sulfoxides, and 2,3-dihydroquinazolin-4(1H)-one derivatives can be synthesized in green conditions. The catalyst can be recovered and recycled for further reactions without appreciable loss of catalytic performance. 相似文献
63.
A new copper (II) coordination complex formulated as [Cu (dipic)(phen)(2-MePy)]. 2H2O ( 1 ) where phen = 1, 10-phenanthroline, dipic2− = pyridine-2,6-dicarboxylato and 2-MePy = 2-methyl pyrrole was synthesized through a simple and environment-friendly reaction under ultrasound irradiation. Also, complex 1 was synthesized by hydrothermal process at 120 °C for 3 days. The corresponding structure of complex 1 was characterized by elemental analysis, atomic absorption spectroscopy (AAS), inductively coupled plasma (ICP), conductivity measurement, Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, ultraviolet–visible spectroscopy (UV–Vis), thermal gravimetric analysis (TGA), differential thermal analysis (DTA), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and fluorescence. The crystal structure of the hydrothermally synthesized complex was characterized by single crystal X-ray diffraction (SC-XRD(, which revealed a triclinic structure. In the remainder of this study, the Cu2O nanoparticles have been prepared via thermal decomposition of hydrothermal and ultrasound complexes and characterized by ICP, FT-IR, powder X-ray diffraction (XRD), SEM and N2 adsorption/desorption. Adsorption and visible-light-driven photocatalytic capabilities of two synthetic Cu2O were investigated in the removal of MB from water. The result showed that the synthesized catalysts have good catalytic activity and the photocatalytic degradation is more effective in dye removal of MB compared with the adsorption. 相似文献
64.
The development of catalysts capable of catalyzing amidation of esters with amines to construct amides under mild conditions is of great importance. Compared to aliphatic amines, the direct catalytic amidation of esters with less nucleophilic aromatic amines is rather difficult. Employing simple lanthanide tris (amide) complexes Ln[N (SiMe3)2]3(μ-Cl)Li (THF)3 as the catalysts, it was found a broad range of aromatic amines and esters were efficiently converted into various amides in good yields under mild conditions. A plausible mechanism for this transformation was experimentally supported as starting from an amide exchange reaction between the lanthanide tris (amide) complex and the substrate amine. 相似文献
65.
Tamara Alhilfi Pierre Chambon Steve P. Rannard 《Journal of polymer science. Part A, Polymer chemistry》2020,58(10):1426-1438
Ambient temperature-initiated anionic polymerization has generated branched polystyrenes of varying molecular weights and architectures by inclusion of a distyryl branching comonomer into a conventional sec-Butylithium-initiated polymerization of styrene. Primary chain length control within the branched polymers, and restriction of the branching points to varying segments of the primary chains, led to variations of glass transition temperature with no direct correlation to the branched polymer molecular weight but a strong relationship to the length of individual chains comprising the branched macromolecules. 相似文献
66.
Xiaojuan Liu Qingqing Wen Prof. Dr. Li Xiang Dr. Xuebing Leng Prof. Dr. Yaofeng Chen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(24):5494-5499
The synthesis and catalytic applications of trivalent rare-earth metal alkyl complexes have been well developed, but the chemistry of divalent rare-earth metal alkyl complexes lagged much behind. Herein, we report the synthesis, structure, and catalytic applications of a samarium(II) monoalkyl complex supported by a β-diketiminato-based tetradentate ligand, [LSmCH(SiMe3)2] (L=[MeC(NDipp)CHC(Me)NCH2CH2N(Me)CH2CH2NMe2]−, Dipp=2,6-(iPr)2C6H3). This complex is synthesized by the salt metathesis reaction of samarium iodide [LSm(μ-I)]2 and KCH(SiMe3)2 in 63 % yield. Its structure is characterized by single-crystal X-ray diffraction, showing a distorted square-pyramid coordination geometry. This samarium(II) monoalkyl complex exhibits high catalytic activity in the hydrosilylation of aryl and methyl-substituted unsymmetrical internal alkynes with secondary hydrosilanes, selectively providing the α-(E) products in high yields. 相似文献
67.
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69.
Rose Morris-Wright 《Journal of Pure and Applied Algebra》2021,225(1):106468
Parabolic subgroups are the building blocks of Artin groups. This paper extends previous results of Cumplido, Gebhardt, Gonzales-Meneses and Wiest, known only for parabolic subgroups of finite type Artin groups, to parabolic subgroups of FC-type Artin groups. We show that the class of finite type parabolic subgroups is closed under intersection. We also study an analog of the curve complex for mapping class group constructed by Cumplido et al. using parabolic subgroups. We extend the construction of this complex, called the complex of parabolic subgroups, to FC-type Artin groups. We show that this simplicial complex is, in most cases, infinite diameter and conjecture that it is δ-hyperbolic. 相似文献
70.
以5-磺基水杨酸和咪唑衍生物为配体合成了单核、双核结构的三元混配Cu(Ⅱ)配合物:[Cu(H2biim)(Hssal)(H2O)2]·H2O(1)和{[Cu(MeHbiim)(Hssal)(H2O)]·0.5H2O}2(2)(H3ssal=5-磺基水杨酸,H2biim=2,2’-联咪唑,MeHbiim=N-甲基-2,2’-联咪唑),并利用元素分析、红外光谱、紫外-可见光谱、X-射线单晶衍射及热重分析等技术手段对其结构进行了表征。单晶结构解析表明配合物1属于单斜晶系,P21/C 空间群,Cu(Ⅱ)离子与1个5-磺基水杨酸根、2个水分子以及1个联咪唑分子形成五配位四角锥构型的单核配合物结构。配合物2属于正交晶系,P2(1)2(1)2(1)空间群,双核Cu(II)离子分别处于五配位四角锥和四配位平面四边形的几何构型的配位环境中,与配合物1不同,5-磺基水杨酸采取μ2双-单齿配位模式。荧光光谱分析表明配合物2具有较强的荧光性。 相似文献