Molar-ratio method

The stoichiometry for the complexes formed with host 8 embedded in the bilayer membrane and the guest was investigated by the molar ratio method [62]. A plot of the [0] value for 8 against the concentration of Orange G reveals that 8 embedded in the bilayer vesicle forms a complex with Orange G in a 1 1 molar ratio. The same 1 1 stoichiometry was confirmed for other complexes. The formation constants (K) for the 1 1 host-guest complexes in the bilayer... 

The composition of iron(III) cupferronate in chloroform was determined photometrically at 325 and 385 nm by the molar ratio methods.101 At both wavelengths the composition of the complex was found to be Fe(PhN202)3. The crystal structure of the complex was determined by three-dimensional Fourier and least-square methods.102 The crystals are monoclinic with a = 12.50, b = 17.45, c = 11.15 A, / = 122° 19 and z = 4 the space group is F2X /a. The cupferron groups are unsymmet-rically attached to iron and are, therefore, crystallographically independent. The Fe—O bond seems to be ionic. 

Stability constants were determined from spectrophotometric titration data treated by molar-ratio method procedures. In all cases only 1 1 complexes were assumed to form. Thus, the molar absorbtivities and the conditional stability constants in Table IV reflect this assumption. 

Molar-Ratio Method. In this method, the concentration of one component is kept fixed and that of the other varied to give a series of [L]/[M] ratios. The absorbances of these solutions, measured at an absorption maximum for the complex M Lp, increase linearly up to the molar ratio of the complex, at which virtually the whole amount of both components is complexed (assuming little dissociation). Further addition of component L cannot increase the absorbance, and the line becomes horizontal, or shows a break if component L absorbs at the same wavelength (Fig. 

In rare cases, an excess component L may cause a decrease in absorbance owing to the stepwise formation of higher-order complexes that have smaller e values at this wavelength. The composition of molybdogermanic acid has been studied by the molar-ratio method [13] showing a ratio of 36 molybdate 1 germanate. 

The reaction mechanism of the present method was as reported earlier (Busev A.I., et al. 1981). Job s method of continuous variation and the molar ratio method were applied to ascertain the stoichiometric composition of the complex (MacCarthy P. and Zachary D.H.,... 

The molar ratio method demonstrated the formation of complexes of a stoichio-... 

The metal-ligand ratios and the formation constants of low M.W. complexes can be obtained by means of graphical methods such as Job s continuous variation [2], dilution method and molar ratios method [3,4], as well as by numerical methods [5] in the treatment of the complicated equilibria which have to be taken into account. For the polymeric complexes Job s method, which has been successfully applied to metal-enzyme complexes [6], Scatchard s method [7] and the numerical methods, modified for the polyelectrolyte effect, are still suitable. 

METHOD 3 [114]-Phenol and 30% H2O2 in molar ratios of 10 3 to 10 8 is heated at 70 C for 8-10 hours to give -15% catechol. Addition of tert-butyl alcohol increases the yield. 

Amination. Isopropyl alcohol can be aminated by either ammonolysis ia the presence of dehydration catalysts or reductive ammonolysis usiag hydrogeaatioa catalysts. Either method produces two amines isopropylamine [75-31-0] and diisopropylamine [108-18-9]. Virtually no trisubstituted amine, ie, triisopropyl amine [122-20-3], is produced. The ratio of mono- to diisopropylamine produced depends on the molar ratio of isopropyl alcohol and ammonia [7664-41-7] employed. Molar ratios of ammonia and hydrogen to alcohol range from 2 1—5 1 (35,36). 

A convenient method of compositional designation uses molar percentages of ester and carbonate linkages coupled with the molar percentages of iso- and terephthalate units in the polymer. A 70% ester, 30% carbonate polyester carbonate with 60 parts of isophthalate and 40 parts of terephthalate is designated 70(60/40)30. Similarly, a standard PC resin is 0(0/0)100, and a polyarjlate resin composed of a 1 1 molar ratio of iso- to terephthalate units esterfied with bisphenol A is designated 100(50/50)0. 

The recommended method to use to determine the actual theoretical stages at an actual reflux ratio is the Erbar/Maddox relationship. In the graph, N is the theoretical stages and R is the actual reflux ratio L/D, where L/D is the molar ratio of reflux to distillate. N, is the minimum theoretical stages and R, is the minimum reflux ratio. 

ZnTe The electrodeposition of ZnTe was published quite recently [58]. The authors prepared a liquid that contained ZnGl2 and [EMIM]G1 in a molar ratio of 40 60. Propylene carbonate was used as a co-solvent, to provide melting points near room temperature, and 8-quinolinol was added to shift the reduction potential for Te to more negative values. Under certain potentiostatic conditions, stoichiometric deposition could be obtained. After thermal annealing, the band gap was determined by absorption spectroscopy to be 2.3 eV, in excellent agreement with ZnTe made by other methods. This study convincingly demonstrated that wide band gap semiconductors can be made from ionic liquids. 

An initial solution was prepared by dissolving metallic niobium powder in 40% hydrofluoric acid. The dissolution was performed at elevated temperature with the addition of a small amount of nitric acid, HN03, to accelerate the process. The completeness of niobium oxidation was verified by UV absorption spectroscopy [21]. The prepared solution was evaporated to obtain a small amount of precipitate, which was separated from the solution by filtration. A saturated solution, containing Nb - 7.01 mol/1, HF - 42.63 mol/1, and corresponding to a molar ratio F Nb = 6.08, was prepared by the above method. The density of the solution at ambient temperature was p = 2.0 g/cc. Concentrations needed for the measurements were obtained by diluting the saturated solution with water or hydrofluoric acid. 

An unusual method has been used to prepare a hyperbranched polyimide starting from two monomers a difunctional A2 and a trifunctional B3. The gel formation can be avoided with careful control of the polycondensation conditions (molar ratio, order of the monomer addition, and low concentration). The A2 and B3 monomers were respectively 6FDA and tris(4-aminophenyl)... 

There is even a method for preparing carboxymethylated surfactants with a narrow polyoxyethylene chain distribution by using as catalyst metallic Na or NaH in a molar ratio of about 1 1 to the fatty alcohol [12,13]. 

The compounds AlYX are best prepared by direct reaction between the respective aluminum halide and chalcogenide in a sealed ampoule at 350°C. The reaction is complete after 2 weeks. In the case of the iodides, a mixture of A1 and I2 (molar ratio 3 10) is used instead of AII3. Other preparative methods, such as the reaction of an aluminum halide with Zn or Cd chalcogenide, or with the chalcogen itself, are applicable to the bromide and chloride only, and give poor yields (15-20%) (158, 159, 266, 327, 328). 

Imides can be prepared by the attack of amides or their salts on acyl halides, anhydrides, and carboxylic acids or esters. The best synthetic method for the preparation of acyclic imides is the reaction between an amide and an anhydride at 100°C catalyzed by H2S04. When acyl chlorides are treated with amides in a2 l molar ratio at low temperatures in the presence of pyridine, the products are N,N-diacylamides, (RCO)3N. ... 

In the Li-Rh system LiRh is prepared from rhodium metal foil and liq Li in a 25 at% excess of the 1 1 molar ratio. The mixture is heated in an iron crucible to 750-880°C in Ar. The direct reaction of the elements in a molybdenum crucible at 800°C for 7 d produces LiRh. Identical methods produce Lilr and Lilrj with which the rhodium compounds are isostructural . The reaction of Rh metal with LiH at 600°C gives the ternary hydrides Li4RhH4 and Li4RhH5. 

A more convenient method uses the oxidation of Sg, dissolved in CH2CI2 or CS2, by trifluoroperoxoacetic acid at temperatures between -10 and 0 °C (molar ratio 1 1.5) ... 

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