نتایج جستجو برای: carbenes

تعداد نتایج: 999  

Journal: :Physical chemistry chemical physics : PCCP 2016
Sascha Gehrke Oldamur Hollóczki

In this work we present a set of force fields for nine synthetically relevant and/or structurally interesting N-heterocyclic carbenes, including imidazol-, thiazol-, triazol-, imidazolidin-, and pyridine-ylidenes. The bonding parameters were calculated by using a series of geometry optimizations by ab initio methods. For fitting the non-bonding interactions, a water molecule was employed as a p...

Journal: :Synfacts 2023

Key words SCAD - lactams N-heterocyclic carbenes single-carbon homologation

Journal: :Chemical communications 2005
Rohit Singh Steven P Nolan

The versatile nucleophilic organic catalysts N-heterocyclic carbenes (NHCs) have been shown to effectively mediate the transesterification of phosphorus esters under mild conditions; user-friendly imidazolium salts can also be employed as pre-catalysts.

Journal: :Journal of Industrial & Engineering Chemistry 1910

Journal: :Chemistry 2018
Stefan Vanicek Maren Podewitz Christopher Hassenrück Michael Pittracher Holger Kopacka Klaus Wurst Thomas Müller Klaus R Liedl Rainer F Winter Benno Bildstein

Oxidative addition of cobaltoceniumdiazonium bis(hexafluoridophosphate) with (pseudo)halide aurates gave gold(III) complexes containing zwitterionic cobaltoceniumide as a ligand. Its selenium derivative, cobaltoceniumselenolate, was obtained by an electrophilic aromatic substitution reaction of iodocobaltocenium iodide with Na2 Se. Spectroscopic and structural data in combination with DFT calcu...

Journal: :Journal of Materials Chemistry C 2022

Cyclometallated N-heterocyclic carbenes with an appended carbazole and chelating diphosphines brought together to achieve the first simple solution-processed green-emitting iTMC-LECs based on mononuclear Pt( ii ) complexes.

Journal: :Karadeniz fen bilimleri dergisi 2023

N-heterocyclic carbenes have initially attracted great attention of the chemists in consequence their catalytic activity. The favorable results were also obtained bioactivity studies for carbenes, and transition metal complexes following years. Theoretical methods deliver beneficial data about several activities molecules. One them is frontier orbital analysis, which supplies reactivity Another...

Journal: :Topics in Applied Physics 2022

Abstract The helium droplet is an ideal environment to spectroscopically probe difficult prepare molecular species, such as radicals, carbenes and ions. quantum nature of at 0.4 K often results in spectra that are sufficiently resolved evoke analysis line shapes fine-structure via rigorous “effective Hamiltonian” treatments. In this chapter, we will discuss general experimental methodologies a ...

2008
Laszlo Mercs Gaël Labat Antonia Neels Andreas Ehlers Martin Albrecht

A series of new piano-stool iron(II) complexes comprising monoand bidentate chelating N-heterocyclic carbene ligands [Fe(cp)(CO)(NHC)(L)]X have been prepared and analyzed by spectroscopic, electrochemical, crystallographic, and theoretical methods. Selectively substituting the L site with a series of ligands going from carbene to pyridine to CO suggests that CO is the strongest π acceptor, whil...

2009
Jin Wang Natalia V. Lebedeva Matthew S. Platz Malcolm D. E. Forbes

Time-resolved (CW) EPR spectroscopy at X-band has been used to detect free radicals created by H-atom abstraction reactions of photochemically generated carbenes in n-hexadecane solutions at room temperature. Three different carbenes were studied, formed via loss of nitrogen after photo-excitation of a substituted biphenyl diazo precursor. The TREPR signals from two different alkyl radicals and...

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