نتایج جستجو برای: salen

تعداد نتایج: 813  

2017
V. Duraisamy

A series of substituted 2-(2-hydroxyphenylimino) phenolic (salen) derivatives (1-4) have been synthesized and their structures of obtained compound were characterized by analytical, FT-IR, UV-Vis and C{H}-NMR experimentally. The geometry structure optimization, frequencies (IR), NMR, electronic character, frontier molecular orbital (HOMO-LUMO) and first static hyperpolarizability (βtot) studies...

Journal: :The Journal of organic chemistry 2003
Luigi Cavallo Heiko Jacobsen

Presented are density functional calculations on various Mn(salen) systems that are active catalysts in the epoxidation of olefins. Correlation of various structural properties such as Mn=O bond strengths, atomic charges, and C-O distances of evolving bonds in transition state geometries with modified Hammett constants reveal a mechanistic picture of the epoxidation reaction, supporting previou...

Journal: :Dalton transactions 2011
Robert M Haak Ana M Castilla Marta Martínez Belmonte Eduardo C Escudero-Adán Jordi Benet-Buchholz Arjan W Kleij

The use of olefin metathesis as a construction tool for multimetallic salen-based structures is described. The approach involves mono- and diallyl-functionalized metallosalen complexes that can be directly coupled by metathesis leading to dimetallic species or mixtures of linear and cyclic oligomers. The metathesis of bis-allyl Ni(salen) complexes has been studied in detail. At high concentrati...

2008
Wai-Lun Man Hoi-Ki Kwong William W. Y. Lam Jing Xiang Tsz-Wing Wong Wing-Hong Lam Wing-Tak Wong Shie-Ming Peng Tai-Chu Lau

Reaction of [RuVI(N)(L1)(MeOH)]+ (L1 ) N,N′-bis(salicylidene)-o-cyclohexylenediamine dianion) with excess pyridine in CH3CN produces [Ru(L)(py)2] and N2. The proposed mechanism involves initial equilibrium formation of [RuVI(N)(L1)(py)]+, which undergoes rapid N · · · N coupling to produce [(py)(L1)RuIIINtN-RuIII(L1)(py)]2+; this is followed by pyridine substituion to give the final product. Th...

2013
Michael North James M Watson

Structurally well-defined bimetallic titanium(IV) (salen) and monometallic vanadium(V) (salen) complexes have been used as catalysts for the asymmetric addition of trimethylsilyl cyanide to β-nitroalkenes to produce chiral nitronitriles with ee values in the range of 79-89 % and conversions up to 100 % at 0 °C. The reaction conditions (solvent, temperature, time and vanadium complex counter-ion...

2014
Jing Du Fangyi Cheng Shiwen Wang Tianran Zhang Jun Chen

Carbonaceous materials containing non-precious metal and/or doped nitrogen have attracted tremendous attention in the field of electrochemical energy storage and conversion. Herein, we report the synthesis and electrochemical properties of a new family of nitrogen-doped metal/carbon (M/N/C, M = Fe, Co, Ni) nanocomposites. The M/N/C nanocomposites, in which metal nanoparticles are embedded in th...

Journal: :physical chemistry and electrochemistry 0

the electrochemical behavior of a modified carbon paste electrode (mcpe) with n,n′ethylenbis(salicylideneiminato)copper(ii) complex ([cu(ii)-salen]) was investigated as a newsensor for cystein. the britton-robinson buffer with ph 5, 10% modifier in electrode, potentialscanning rate of 20 mvs-1 and puls height of 50 mv were used as the optimum condition for thedetermination of cysteine using car...

Journal: :Chemical communications 2010
Szabina Góger Dóra Bogáth Gábor Baráth A Jalila Simaan Gábor Speier József Kaizer

This study reports the kinetics and mechanism of Fe(III)-catalyzed oxidative decarboxylation and deamination of a series of acyclic (α-aminoisobutyric acid, α-(methylamino)isobutyric acid, alanine, norvaline, and 2-aminobutyric acid) and cyclic (1-aminocyclopropane-1-carboxylic acid, 1-amino-1-cyclobutanecarboxylic acid, 1-aminocyclopentanecarboxylic acid, and 1-aminocyclohexanecarboxylicacid) ...

2015
Willem K Offermans Claudia Bizzarri Walter Leitner Thomas E Müller

Exploiting carbon dioxide as co-monomer with epoxides in the production of polycarbonates is economically highly attractive. More effective catalysts for this reaction are intensively being sought. To promote better understanding of the catalytic pathways, this study uses density functional theory calculations to elucidate the reaction step of CO2 insertion into cobalt(III)-alkoxide bonds, whic...

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