While initially it seems as though methanol, an organic solvent would be incapable of dissolving a polar acid or base, the conjugate of the acidic and basic compound will dissolve in methanol. The conjugate acid and base were obtained by adding
The % of yield was 78% and melting point of the compound was 190 - 192 0C. Scheme 2: Synthesis of p-toluic hydrazide and 2-hydroxy-4 mehoxy Acetophenone Schiff base B. Synthesis of RAPPTH & HMAPPTH - V (IV) Schiff base Metal Complexes: The reagent p-Toluic hydrazide and Resacetophenone (2,4 Dihydroxyacetophenone) Schiff base was dissolved in 40ml of 50% methanol and V (IV) metal ions dissolved in 20ml of distilled water, this compounds mixture was stirred for 6 hours in the presence of sodium acetate. Orange red color metal complex (RAPPTH) was formed with good yield. This product washed several times with hot water and cold methanol to free from un reacted metal slats and ligand respectively and finally with ether and dried in vacuo over calcium chloride
1-Aryl-2,3,5-trimethylpyrazolium ionic liquids Melek Canbulat Özdemir1 and Beytiye Özgün* Department of Chemistry, Faculty of Science, Gazi University, 06500 Teknikokullar, Ankara, Turkey Abstract A series of new 1-aryl-2,3,5-trimethylpyrazolium ionic liquids were synthesized and characterized. The influence of electron-withdrawing and -donating substituent at the para-position of the phenyl ring (-NO2, -Cl, -Br, -H, -Me, -OMe) on the properties of synthesized salts were investigated by keeping alkyl part constant (methyl) for anions CH3SO3-, BF4- and PF6-. Thermal properties (melting points, thermal stabilities) and electrochemical stabilities (EW) of all salts were investigated. In addition, thermophysical properties ( density, viscosity and refractive index) of liquid salts at room temperature ( 2a,2b, 2d, 2e) were measured as a function of temperature. The results indicated that ordinarily electron-withdrawing substituents increases melting points of pyrazolium salts while –donating substituents decreases their melting points.
When Phenolphthalein is added to Soda water, the resultant solution is colourless. After titration with a strong base (sodium hydroxide), the solution will turn to pink as the solution becomes
When phase separation occurs alongside increasing temperature, especially upon reaching the melting point of HS polymer, a homogeneous viscous melt could form. For most polyurethane materials thermal degradation starts at the melting point of HS, while all mechanical properties reduce with dissolving of the HS area in the SS area. For applications where the applied temperature is discrete through the material thickness, it indeed becomes very difficult to predict the properties
Figure 1(c) reveals that when Cr(NO3)3 concentration increased from 0.2 to 1.2 M, the nanocellulose crystallinity progressively increased from 62.5 to 83.9% while maintaining reaction duration for 1.5 h, a solid-liquid ratio of 1:30 at 80 °C. At the same time, the product yield decreased almost linearly with increasing concentration of metal salt. This implied that the successive degradation of amorphous allomorphs after the catalytic hydrolysis process and this induces the exposure of high crystallite segment in the nanocellulose which led to increasing of crystallinity. However, it is worth mentioning that the increasing tendency of crystallinity index became slower when the metal salt concentration was higher than 0.8 M. Therefore, for better economic competence, 0.8 M of metal salt catalyst was selected as an optimum concentration for
This spectrophotometric assay uses the stable radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH) as a reagent. 2 mL of several different concentrations of the samples were mixed with 2 mL of 0.004% DPPH in methanol. The mixture was shaken vigorously and then immediately stored in the dark for 30 minutes at room temperature before placed in a UV-Vis spectrophotometer to monitor the decrease in absorbance at 517 nm. Methanol was used as a blank and methanol mixed with DPPH in methanol was used as a positive control. Ascorbic acid, a stable antioxidant, was used as a synthetic reference.
After the reaction, the mixture was permitted to settle overnight and the top layer (methanol–water) was separated. Filtration was used to remove insoluble catalyst in the mixture. Also the methanol in the lower layer was recovered using rotational evaporator under vacuum at 50
1 tablet of PBS were dissolved in 100 mL deionized water and kept at 4 °C. 2.2.5 Penicilin/streptomycin stock solution (PenStrap) The PenStrap solution was ready-made use purchased from GIBCO Company. 2.2.6 Trypsin (0.25 %, w/v)/EDTA 1X solution A 0.25% trypsin from bovine pancreas was used to detach the cultured cells from the flask. The trypsin solution was obtained from GIBCO Company. 2.2.7 Dimethyl sulfoxide (DMSO) ≥99% The DSMO acquired from Merck acts as cryoprotectant agent to reduce the formation of ice so that the cell death during the freezing process will prohibited.
The solution was filtered through 0.22 µm membrane filter and degassed by sonicate for 5minutes. Mobile phase A: 0.02M ammonium acetate buffer PH 4.0 Mobile phase B: Methanol The mobile phase was prepared by mixing Mobile phase A and Mobile phase B in the ratio of 35:65.Then it was filtered and degassed. The trial plot was shown in figure Diluent preparation: Taken 1000ml of methanol into a 1 litre mobile phase bottle, mixed well and degassed by sonicating for 5 minutes. Chromatographic conditions Instrument : LC-MS/MS 8030 Column : YMC pack pro C18 ,100 x 4.6mm, 3µm Flow rate : 1. ml/min Column temperature : Ambient Injection volume :