نتایج جستجو برای: imidazolium based salts

تعداد نتایج: 2959675  

2013
ANA MARIA ZBANCIOC ANCA MIRON COSTEL MOLDOVEANU GHEORGHITA ZBANCIOC

We report herein a feasible study concerning syntheses and structure of some diazolium salts with dihydroxyacetophenone skeleton of anticipated anticancer activity. A fast, general and facile method for preparation of 1,3-diazol salts via N-alkylation reactions under conventional heating and microwave irradiation is presented. The microwaves remarkably accelerated these N-alkylations, the react...

2011
Steffen Meyer Claudia Manuela Orben Serhiy Demeshko Sebastian Dechert Franc Meyer

A series of new and known bis(imidazolium) chloride and bromide salts bridged by either a methylene group (1−8, 10a,b) or an ethylene group (9a,b) and bearing different N substituents (Me, Et, Bn, tBu, Mes) have been reacted with [Fe{N(SiMe3)2}2]2 to yield the four-coordinate iron(II) complexes [LFeX2] (11−20; X = Cl, Br; L = chelating bis(imidazolylidene) ligand). Molecular structures of six o...

2005
Andrew P. Abbott Thomas J. Bell Sandeep Handa Barry Stoddart

The application of ionic liquids as environmentally benign reaction solvents for synthesis and catalysis has received extensive recent attention. In this regard we have developed ionic liquids based on the cheap and readily available components choline chloride (ChCl; HOCH2CH2N(Me)3?Cl) and zinc chloride as alternatives to the more commonly employed alkyl imidazolium-aluminium chloride mixtures...

Journal: :Dalton transactions 2007
Ermitas Alcalde Rosa M Ceder Cristina López Neus Mesquida Guillermo Muller Sandra Rodríguez

The synthesis of simple imidazolium-based ligand precursors containing a 1,3-alkylidene-2,4,6-trimethylbenzene spacer was examined and different synthetic protocols were applied depending on the nature of the alkylidene arm. For a methylene arm, simple dications 5a,b.2CI were obtained directly. The higher homologue counterparts were conveniently prepared by general multistep routes following a ...

Journal: :Dalton transactions 2009
Preston A Chase Austin L Gille Thomas M Gilbert Douglas W Stephan

The chemistry of frustrated Lewis pairs derived from N-heterocyclic carbenes and a number of Lewis acids has been probed. The combination of 1,3-bis[2,6-(di-iso-propyl)phenyl]-1,3-imidazol-2-ylidene (IDipp) (1) with B(C6F5)3 was shown to give the classical Lewis acid-base adduct (IDipp)B(C6F5)3 (2) which was unreactive. In contrast, the combination 1,3-di-tert-butyl-1,3-imidazol-2-ylidene (3) w...

Journal: :Dalton transactions 2011
Warren B Cross Christopher G Daly Rachel L Ackerman Ian R George Kuldip Singh

With a view to applications in bifunctional catalysis, a modular cross-coupling strategy has been used to prepare amine bis(imidazolium) salts (3a and 3b) and an amine mono(imidazolium) salt (6) as precursors to chelating amido-NHC ligands. Treating the pro-ligands 3 with 3 equivalents of the bulky base KHMDS and Pd(OAc)(2) or PtCl(2)(COD) gave the four amido bis(N-heterocyclic carbene) pincer ...

2006
Takafumi ARAO Kei SATO Kazuhiro KONDO Toyohiko AOYAMA

1 mimicking axial chirality, in which a chiral carbon center induces a preferred conformation 2a by rotation around an N–Ar bond which is fixed by formation of a chelate structure with metal (Fig. 1). In order to expand the scope of our chiral mimetic concept, we planned to develop a novel N-heterocyclic carbene ligand 3. The substituent R on the sp N group in the carbene ligand 3 may be confor...

Journal: :International Journal of Molecular Sciences 2008
Gerelt-Ireedui Sengee Narangerel Badraa Young Key Shim

We have designed imidazolium and piperazinium salts of pyropheophorbide-a in order to develop effective photosensitizers which have good solubility in polar and non polar media and to reveal the possible influences of the piperazine and imidazole moieties on the biological activities of pyropheophorbide-a. The phototoxicity of those pyropheophorbide-a salts against A549 cells was studied in vit...

Journal: :The journal of physical chemistry. B 2007
Jason W Traer James F Britten Gillian R Goward

On the basis of our solid-state NMR characterization of dynamics in two model salts, we draw the analogy to the fuel cell membrane candidate, phosphoric acid-doped poly(benzimidazole), and conclude that phosphate anion dynamics contribute to long-range proton transport, whereas the mobility of the polymer itself is not a contributing factor. This is contrasted with emerging membrane candidates,...

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