Methanol-water solutions

Note that if the water in the reaction is not of unit mole fraction (or nearly so), then its activity would have to be incorporated into equation 20.211. This could for example be in a mixed water/methanol solution. The water... 

The hydrophilic Au SR (RSH = GSH, h-GSH, (PG)SH, (SA)SH) clusters were ionized by the ESI method [15,16,18,23,24] (Figures 2 and 3c). The details of the ESI source are depicted in Figure 3c, together with typical pressures of the chambers under operation. A 50%(v/v) water-methanol solution of the fractionated Au SR cluster with a typical concentration of 0.5mg/mL was electro-sprayed into the ambient atmosphere through the stainless steel needle of a syringe biased at ca. — 3kV. The solution was delivered by a syringe pump (SP310I, World Precision... 

Syntheses of the tri-nuclear complexes were performed in water-methanol solution according to the reaction... 

HPLC ESI MS is also a useful tool in the analysis of non-anthraquinone red dyestuffs. The use of this technique allows the identification of carthamin as the main colour component of safflower.[34] Ten species of the genus Alkanna are extracted with hexane, and dissolved in water-methanol solution after evaporation. [47] Ammonium formate buffer (pH 3.0) was used as the mobile phase modifier. In the preparations, alkannin and many hydroxynaphthoquinones (alkannin derivatives) were identified by comparison of retention times, as mass spectra (in the NI mode) for all compounds consisted only of quasi-molecular peaks. 

Mild extraction was also found to be effective in the analysis of extracts of Flaveria haumanii, l in which quercetin, kaempferol, isorhamnetin as well as their glycosides and sulfate esters were identified. The obtained results were useful in the identification of the colourants from fibres from pre-Columbian Andean textiles extracted with the use of water-methanol solution with formic or hydrochloric acid. The components of each extract were separated on a reversed phase HPLC column and the eluates were monitored at... 

Hwang, D.W., Kim, H.G., Jang, J.S., Bae, S.W., Ji, S.M., Lee, J.S. 2004. Photocatalytic decomposition of water-methanol solution over metal-doped layered perovskites under visible light irradiation. Catal Today 93-5 845-850. 

Single crystals of the D-glucan from Acetobacter xijlinum were prepared in water-methanol solutions at room temperature. Using electron and X-ray diffraction, a hexagonal unit-cell, with a = h = 0.518 nm and c = 2.0 nm, was derived. It was concluded that the chain axes lie parallel to the surface of the lamellar crystals, that there are 2.5 water molecules per /3-D-Glcp residue, and that the structure is similar to that of cellulose hydrate II (Ref. 42). 

Bis adducts of terpyridyl, [Ni(terpy)2]X2, can be obtained in ethanol solutions. The mono adducts can be obtained by thermal decomposition of the corresponding bis adducts or by the reaction of excess nickel salt with the ligand in water-methanol solutions. The [Ni(terpy)2]X2 complexes (X = Cl, Br) are six-coordinate863 whereas the mono adducts NiLX2 are five-coordinate when X = C1 or Br864,865 and polynuclear six-coordinate when X = NCS.866 In the last complex the nickel atoms are ferromagnetically coupled. 

The yield is based on L-ascorbic acid (1) or the salt of 1, when this is possible. Each of a variety of metals (cadmium, cobalt, iron, magnesium, manganese, nickel, and zinc) was individually added to aqueous, or water-methanol, solutions of 29. The yields of L-ascorbic acid ranged from 40 to 85%. These reactions presumably proceed by way of the metal hydroxide. The yield is based on the weight of the salt of L-ascorbic acid. The yield is for the conversion of 28 into 29 into 1. Compound 29 was prepared by using Amberlite 200 (H+) ion-exchange resin it was also prepared directly from 27. 

Based on the above mentioned, the programme of theoretical and experimental investigation of the main parameters of coal-methanol (or its water solution) mixture pipeline transport should be opened. As the first step of the programme the comparison of power consumption (dependency of hydraulic gradient I on slurry flow velocity V and solid concentration Cs) for the pipeline transport of coal-water mixture and coal-methanol solution mixture was realised. The special laboratory measurements were made to define unknown input data of semi-empirical relationships, i.e. the limit volumetric concentration Cm and the coefficient of mechanical friction of coal in the water or water-methanol solution ka. The resultant comparison of the hydraulic gradient I of the coal-water and coal-methanol solution mixture flow is presented in Figure 2, where density of coal was pc = 1480 kg/m3, diameter of the pipe was D = 0.103 mm, the maximal grain size of coal dmax was less than 0.25 mm, volumetric concentration - C = 20 %. 

Figure 3. Comparison of dynamic viscosity p of a real water-methanol solution and its...

Solid state analysis of crystals obtained of receptor with acetate from water/methanol solutions reveal that once again the guanidiniocarbonylpyrrole cation exists in an extended conformation however in contrast to the proposed solution state model, the pyrrole NH points away from the guanidium NHs with the acetate anions bound by two separate receptor groups with solvent molecules helping to create a series of 2D arrays (figure 23c). 

Analytical methods have been published also for the more recent TKIs in early or late phase of clinical development, which comprise vatalanib [119] and axitinib [120], Abbas et al. have developed an analytical method for measurement of the anti-CML bosutinib in plasma of healthy subjects [88], Samples were extracted from plasma by LLE with carbonate buffer pH 10 and 1-chlorobutane (1 10, v/v) prior to evaporation and reconstitution in water/methanol solution (50 50, v/v). 

Lowry, GV and Johnson, KM. (2004) Congener-specific dechlorination of dissolved PCBs by microscale and nanoscale zerovalent iron in a water/methanol solution. Environ. Sci. Technol. 38, 5208-5216. 

The inertness of chromium (III) ion has allowed a complete characterization of the solvation of this ion in several mixed-solvent systems. For this inert transition metal ion of charge 3+, concern with the first shell coordination of solvent molecules can be viewed as a subdivision of coordination chemistry, a point of view less easily applicable to labile systems of metal ions with lower charge. Thus the approach used here is different from that used by A. K. Covington and co-workers (16) in their NMR studies of labile systems (e.g., sodium and cesium chlorides in water-methanol solutions (17)). 

Bis(2,4-pentanedionato)diaquocobalt(II) was first obtained b Gach by warming 2,4-pentanedione (acetylacetone) with precipitated cobalt(II) hydroxide. Jones prepared the compound by adding 2,4-pentanedione to an aqueous solution of hexaamminecobalt(II) ion. Recent workers have employed the method of Charles and Pawlikowski, which consists of adding sodium acetate solution to a water-methanol solution of cobalt(II) chloride and 2,4-pentanedione, followed by recrys-tallization from methanol. Bullen grew crystals from dimethyl-formamide for an x-ray diffraction study. 

Figure 5 Oxygen-oxygen spatial distribution functions g r) for a 3 1 water-methanol solution at 25 °C. Above Water-water correlations for g f) = 2.0. Below Methanol-oxygen density around water for an iso-surface threshold of 1.75.

Over the PtSnT samples the reaction of CO2 with ethylene was studied in the batch reactor. The results of the extraction of reaction products with an acidified 1 1 water-methanol solution are shown in Table 1. In these solutions, 3- and 2-hydroxypropanoic methyl esters were present. The products obtained depended on the reduction temperature T of PtSnT sample. For lower reduction temperatures (473 K and 573 K) both, 3- and 2-hydroxypropanoic methyl esters were obtained. The lower reduction temperature produced the higher quantity of HOCH2CH2COOMe and the lower of CH3CH(OH)COOMe. 

Figures 13.4a and 13.4b compare chromatograms published by Heme et al. [23] and chromatograms calculated from the data formd in their paper, assuming Langmuir competitive isotherms (Eq. 13.3) and numerical values of the other parameters that permit the best approximation of the experimental results. In this experiment, a sample containing acetonitrile, N,N-dimethylformamide, ethyl formate, fso-butanol, ethyl acetate and 1-pentanol is eluted on a C18 chemically bonded silica phase (Nucleosil C18), using a water-methanol solution containing 0.00025 M salicylamide, the UV-absorbing additive. The agreement between experimental and calculated chromatograms is excellent. It demonstrates the validity of the theoretical approach. The system peaks associated with the first five components, those that are eluted before the additive system peak (peak 6), are...

In the former case [32], the production rate of 99% pme enantiomers from the racemic mixture of R- and S-2-phenylbutyric acid was maximized as a function of the sample size and the mobile phase composition. The calculations were based on the column performance and the equilibrium isotherms of the two components (bi-Langmuir isotherms. Chapter 3). The separation was performed on immobilized bovine serum albumin, a chiral stationary phase, using water-methanol solution as the mobile phase. The retention times decrease with increasing methanol content, but so does the separation factor. For this reason, the optimum retention factor is around 3. Calculated production rates agree well with those measured (Table 18.4). The recovery yield is lower than predicted. 

The same ring contraction was also induced by boiling water or on heating at reflux in a water/methanol solution, but in this case methyl cyclopropanecarboxylate ( 20%) was also formed in addition to the expected cyclopropanecarbaldehyde. ... 

From irradiation of (147) in water-methanol solution the methoxy derivative (148) results and the anion produced from (149) gives (150). 

Electropolymerization. One coating method consists in the oxidative electropolymerization onto the surface of the electrode. Films of poly(oxy-phenylene) were initially deposited from a 1 1 (by volume) water methanol solution containing 0.25 M 2-allylphenol, 0.2 M 2-butoxyethanol, and 0.4 M ammonium hydroxide or allylamine by biasing the wires at a constant voltage of 4 volts for half an hour (50). Under these conditions the phenolic groups of the monomers are oxidized, generating a free radical, which ini-... 

This procedure uses readily available reagents and provides a simple and efficient method for nitrile synthesis. The entire sequence of four steps can be performed in a single day. Although product formation in the second step is presumably thermodynamically controlled, the cyanohydrazine is favored in all cases studied except with aryl ketones. A water-methanol solution of ammonium chloride and potassium cyanide can also be employed for the cyanohydrazine formation, but lower yields (ca. 60%) are obtained. The third step, a conveniently performed titration procedure with bromine as oxidant, can be effected with other oxidizing reagents such as 4-phenyl-4H-l,2,4-triazole-3,5-dione, ferl-butyl hypochlorite, and Jones reagent.12 The final diazene-... 

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