نتایج جستجو برای: aqueous solvents

تعداد نتایج: 124013  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه پیام نور - دانشگاه پیام نور استان یزد - دانشکده علوم 1390

در این تحقیق، ابتدا منگنز تترافنیل پورفیرین از طریق لیگاند محوری ایمیدازول به پلی مر متصل گردید و به وسیله روش های مختلفی مانند ir، uv-vis و sem مورد شناسایی قرار گرفت. سپس از این کاتالیست جهت بررسی هیدروژن زدایی ترکیبات مختلف 2-ایمیدازولین به وسیله ترشیوبوتیل هیدروپراکسید در حلال آب استفاده شد. در این بررسی، نیاز به اضافه کردن لیگاند محوری نبود و از این سیستم کاتالیستی تحت هر دو شرایط به همزدن...

2009
P. R. Sathesh Babu C. V. S. Subrahmanyam J. Thimmasetty R. Manavalan K. Valliappan S. A. Kedarnath

Solubility enhancement of meloxicam and rofecoxib, which are poorly soluble in water, was attempted. These are available in the form of solid dosage forms but not in solution dosage forms due to their low aqueous solubility. In this work, aqueous solubility of meloxicam and rofecoxib was improved using the biocompatible solvents such as ethanol, propylene glycol, glycerin, and PEG 400. Physico-...

Journal: :Journal of combinatorial chemistry 2003
Jae Wook Lee Ying Qi Louie Daniel P Walsh Young-Tae Chang

Novel nitrophenol solid supports based on various resin materials (polystyrene, TentaGel, macroporous, PEGA, and silica gel) are reported for facile amide and sulfonamide library synthesis. The broad choice of resin materials available will allow the reaction to occur successfully in solvents ranging from nonpolar organic solvents to aqueous media.

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2006
Hiromichi Yamada Hiroyuki Hayashi Takashi Yasui

Using 1-octanol/octane mixed solvents, the extraction of aluminum(III), gallium(III) and indium(III) with 8-quinolinol was carried out at 25 degrees C. The formation constants of the respective metal(III) 8-quinolinolates in the aqueous phase and their partition constants between the mixed solvents and water were determined based on an analysis of the extraction equilibria. The relationship bet...

2010
Malcolm J. D’Souza Stefan M. Hailey Dennis N. Kevill

The specific rates of solvolysis of S-methyl chlorothioformate (MeSCOCl) are analyzed in 20 solvents of widely varying nucleophilicity and ionizing power at 25.0 degrees C using the extended Grunwald-Winstein Equation. A stepwise S(N)1 (D(N) + A(N)) mechanism is proposed in the more ionizing solvents including six aqueous fluoroalcohols. In these solvents, a large sensitivity value of 0.79 towa...

2005
G. T. Hefter

The thermodynamics of fluoride ion solvation in nonaqueous and mixed aqueous solvents are reviewed. Gibbs energies of transfer , at^ O (F ) H20+ , indicate that the solvation of the fluoride ion is dominated by hydrogen bonding. Thus, at^ o ( ~ ) H 2 0 S is unfavourable for virtually all solvents, especially dipolar aprotics, and correlates well with solvent acceptor strength. The corresponding...

Journal: :Journal of Chemical Education 1968

Journal: :Origins of Life and Evolution of Biospheres 2020

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