排序方式: 共有8条查询结果,搜索用时 78 毫秒
1
1.
Ethan Zars Lisa Pick Dr. Abinash Swain Dr. Mrinal Bhunia Dr. Patrick J. Carroll Prof. Dr. Dominik Munz Prof. Dr. Karsten Meyer Prof. Dr. Daniel J. Mindiola 《Angewandte Chemie (International ed. in English)》2023,62(51):e202311749
Here we report the use of a base metal complex [(tBupyrpyrr2)Fe(OEt2)] ( 1 -OEt2) (tBupyrpyrr22−=3,5-tBu2-bis(pyrrolyl)pyridine) as a catalyst for intermolecular amination of Csp3−H bonds of 9,10-dihydroanthracene ( 2 a ) using 2,4,6-trimethyl phenyl azide ( 3 a ) as the nitrene source. The reaction is complete within one hour at 80 °C using as low as 2 mol % 1 -OEt2 with control in selectivity for single C−H amination versus double C−H amination. Catalytic C−H amination reactions can be extended to other substrates such as cyclohexadiene and xanthene derivatives and can tolerate a variety of aryl azides having methyl groups in both ortho positions. Under stoichiometric conditions the imido radical species [(tBupyrpyrr2)Fe{=N(2,6-Me2-4-tBu-C6H2)] ( 1 -imido) can be isolated in 56 % yield, and spectroscopic, magnetometric, and computational studies confirmed it to be an S = 1 FeIV complex. Complex 1 -imido reacts with 2 a to produce the ferrous aniline adduct [(tBupyrpyrr2)Fe{NH(2,6-Me2-4-tBu-C6H2)(C14H11)}] ( 1 -aniline) in 45 % yield. Lastly, it was found that complexes 1 -imido and 1 -aniline are both competent intermediates in catalytic intermolecular C−H amination. 相似文献
2.
Single‐molecule magnets based on lanthanides are very attractive due to their potential applications proposed in the area of microelectronic devices. Very recent advances in this area are due to the blend of conventional lanthanide chemistry with organometallic ligands, and several breakthrough achievements are attained with this combination. Ab initio methods based on multi‐reference CASSCF calculations are playing a vital role in the design and development of such molecules. In this minireview, we aim to appraise various contributions in the area of organometallic lanthanide complexes (those containing lanthanide‐carbon bonds) and describe how these robust wavefunction‐based methods have played a constructive role not only in rationalizing the observed magnetic properties but also proven to be a potential predictive tool with some selected examples. 相似文献
3.
Slow Magnetic Relaxation and Single‐Molecule Toroidal Behaviour in a Family of Heptanuclear {CrIIILnIII6} (Ln=Tb,Ho, Er) Complexes 下载免费PDF全文
Dr. Kuduva R. Vignesh Dr. Stuart K. Langley Abinash Swain Dr. Boujemaa Moubaraki Dr. Marko Damjanović Prof. Wolfgang Wernsdorfer Prof. Gopalan Rajaraman Prof. Keith S. Murray 《Angewandte Chemie (International ed. in English)》2018,57(3):779-784
The synthesis, magnetic properties, and theoretical studies of three heterometallic {CrIIILnIII6} (Ln=Tb, Ho, Er) complexes, each containing a metal topology consisting of two Ln3 triangles connected via a CrIII linker, are reported. The {CrTb6} and {CrEr6} analogues display slow relaxation of magnetization in a 3000 Oe static magnetic field. Single‐crystal measurements reveal opening up of the hysteresis loop for {CrTb6} and {CrHo6} molecules at low temperatures. Ab initio calculations predict toroidal magnetic moments in the two Ln3 triangles, which are found to couple, stabilizing a con‐rotating ferrotoroidal ground state in Tb and Ho examples and extend the possibility of observing toroidal behaviour in non DyIII complexes for the first time. 相似文献
4.
Mahapatro Abinash Kumar Alok Mahanta Pinakeswar 《Journal of Thermal Analysis and Calorimetry》2020,141(6):2635-2645
Journal of Thermal Analysis and Calorimetry - The present work is to study the effect of pressure on the gasification of sugarcane bagasse in a pressurized circulating fluidized bed reactor. The... 相似文献
5.
Prof. Dr. Peter Comba Prof. Dr. Markus Enders Dr. Michael Großhauser Dr. Markus Hiller Prof. Dr. Rüdiger Klingeler Dr. Changhyun Koo Dr. Dennis Müller Prof. Dr. Gopalan Rajaraman Abinash Swain Msia Tavhelidse Prof. Dr. Hubert Wadepohl 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(36):9372-9382
6.
Dr. Prabhakaran Rajasekar Abinash Swain Prof. Dr. Gopalan Rajaraman Prof. Dr. Ramamoorthy Boomishankar 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(39):10012-10015
The synthesis of cages with a polyradical framework remains a challenging task. Herein is reported an enantiomeric pair of quinoid-bridged polyradical tetrahedral palladium(II) cages that are stabilized by an unusual dianionic diradical form (dhbq..2−). These cages have been characterized by electron paramagnetic resonance and UV-visible spectroscopy, squid magnetometry and mass spectrometry. Single-crystal-derived X-ray investigations of the iso-structural cages built on fluoranilate linkers confirm the tetrahedral structure of the obtained radical cages. Theoretical calculations showed that the diradical state of the dhbq anions is more stable than the usual monoradical state. A weak ferromagnetic exchange between adjacent radical centers was observed in DFT studies. 相似文献
7.
Hepcidin is a small cysteine-rich peptide that plays an important role in antimicrobial activity and in maintaining iron homeostasis
in vertebrates. Here we report on the underlying mechanism that maintains high sequence diversities among the hepcidin-like
variants of perciform and pleuronectiform fishes. In contrast to mammals, maximum likelihood-based codon substitution analyses
revealed that positive Darwinian selection (nonsynonymous to synonymous substitution, ω > 1) is the likely cause of accelerated rate of amino acid substitutions in the hepcidin mature peptide region of these
fishes. Comparison of models incorporating positive selection (ω > 1) at certain sites with models not incorporating positive selection (ω < 1) failed to reject (p = 0) the evidence of positive selection among the codon sites of percifom and pleuronectiform hepcidin. The adaptive evolution
of this peptide in perciform and pleuronectiform fishes might be directed by pathogens when the host is exposed to new habitats/environments. 相似文献
8.
Zusammenfassung Die Bewegungsgleichungen für die Strömung einer nicht-Newtonschen Flüssigkeit nahe einem Staupunkt sind integriert worden nach der Kármán-Pohlhausen-Methode. Es ist gefunden worden, dass der Effekt der Querviskosität von einem dimensionslosen ParameterK=c
a/u abhängt. Die Grenzschichtdicke nimmt ab vonK=0 zuK=0,15 und wächst dann mitK, Die Wand-Scherbeanspruchung nimmt ab mit zunehmendemK, während die Normalkraft an der Wand unabhängig ist von Viskosität und Querviskosität. 相似文献
1