نتایج جستجو برای: reaction temperature

تعداد نتایج: 839282  

Journal: :iranian journal of catalysis 2013
hassan tajik khodabakhsh niknam somayeh karimian

in this research, different alcohols and phenols are subjected to the reaction with hmds in the presence of ionic liquid and silica-supported catalysts. silylation was accomplished under mild reaction conditions at room temperature in short reaction times and good to excellent yields.

Journal: :iranian journal of catalysis 2013
bijan mombani godajdar ali reza kiasat

regarding the green chemistry's goals, dicationic magnetic room temperature ionic liquid open up new avenue to introduce an amazing and efficient system for facilitating catalyst recovery in different organic reactions. ability of this dicationic magnetic room temperature ionic liquid catalyst in the one-pot three-components condensation reaction of benzil, aromatic aldehyde, and ammonium aceta...

Journal: Polyolefins Journal 2014

A fourth-generation Ziegler-Natta catalyst was prepared to synthesize polypropylene (PP), which was stabilized by in situpolymerization employing lignin as antioxidant. The antioxidant properties of lignin were compared with those of the commercial antioxidant Irganox 1010. The presence of lignin in the reaction medium slightly decreased the catalytic activity of the reaction. The isotacticity ...

ژورنال: :international journal of new chemistry 0

in this study the reaction of the derivative , material [1,5-b]  tetrazolo [1,2,4] terry inflorescences (tta)  with boron nitride nano- cages in different conditions of temperature , density functional theory methods were studied . for this purpose, the material on both sides were geometrically optimized reaction , then the calculation of the thermodynamic parameters were performed on all of th...

Journal: :Organic & biomolecular chemistry 2010
Shigeo Kohmoto Shugo Hisamatsu Hakuei Mitsuhashi Masahiro Takahashi Hyuma Masu Isao Azumaya Kentaro Yamaguchi Keiki Kishikawa

Intramolecular [2+2] photocycloaddition of aromatic chain imides possessing bis-phenanthrene moieties afforded straight and cross ring closure products. The ratio of cycloadducts was dependent on reaction time and temperature, which resulted in a reversal of regioselectivity. The reaction was proved to involve a retro cycloaddition. The cross ring closure products were formed predominantly in t...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید بهشتی - دانشکده علوم 1371

we describe here a suitable approach for the synthesis of n-unsubstituted monocyclic b-lactams under mild reaction conditions by the annelation of imines with substituted acetylchlorides. in this method the reaily available phtalimidoacetyl chloride were allowed to react with - dibenzylideneiminotoluene (hydrobenzamide) in the presence of an equimolar amount of triethylamine in refluxing toluen...

The pseudo-first order rate constants and activation parameters have been determined using two methods, constant-temperature kinetic (CTK) and variable temperature kinetic (VTK), for the oxidative addition reactions of [Pt2Me2(C^N)2(µ-dppf)], (1a, C^N = deprotonated 2-phenylpyridine (ppy); 1b, C^N = deprotonated benzo[h]quinoline (bhq)) with MeI. The results obtained from VTK method are in agre...

Journal: :The American naturalist 2002
Stevan J Arnold Charles R Peterson

We present a model to test Osgood's ( 1978 ) proposition that viviparous snakes have optimal reaction norms for temperature-sensitive meristic traits, such as scale counts. Our model predicts that traits that are subject to temperature effects during development will evolve a flat or [Formula: see text]-shaped reaction norm (average scale count as a function of developmental temperature). We te...

Journal: :The American naturalist 2009
Jennifer L Knies Joel G Kingsolver Christina L Burch

Hotter is better is a hypothesis of thermal adaptation that posits that the rate-depressing effects of low temperature on biochemical reactions cannot be overcome by physiological plasticity or genetic adaptation. If so, then genotypes or populations adapted to warmer temperatures will have higher maximum growth rates than those adapted to low temperatures. Here we test hotter is better by meas...

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