Hydroxide, addition

There is no evidence for the existence of thallic hydroxide addition of hydroxide to an aqueous solution of a T1(III) salt gives TI2O2 instead. ThaHous hydroxide can be isolated as yellow needles by the hydrolysis of thaHous ethoxide [20398-06-5] which is conveniendy prepared as a heavy oH by the oxygen oxidation of thallium metal in ethanol vapor. ThaHous hydroxide darkens at room temperature and decomposes to TI2O and H2O on warming. 

Hydrous Oxides and Hydroxides. Hydroxide addition to aqueous zirconium solutions precipitates a white gel formerly called a hydroxide, but now commonly considered hydrous zirconium oxide hydrate [12164-98-6], 7 0 - 112 0. However, the behavior of this material changes with time and temperature. 

Alkali Metal Hydroxides. Addition of base to aqueous chloroformates cataly2es hydrolysis to yield the parent hydroxy compound (11). However, the use of a stoichiometric amount of alkaU metal hydroxides can lead to the symmetrical carbonate, especially from aryl chloroformates (12,13). 

Other options for the purification of CA include dissolution in hot water, aqueous ammonia, aqueous formaldehyde, or hot dimethylformamide followed by filtration to remove most of the impurities. The CA is recoverable by cooling the aqueous solution (84), acidifying the ammonium hydroxide solution (85), or cooling the dimethylform amide solution with further precipitation of CA by addition of carbon tetrachloride (86). Sodium hydroxide addition precipitates monosodium cyanurate from the formaldehyde solution (87). 

Even alkyl benzoate esters give only a small amount of exchange imder basic hydrolysis conditions. This means that reversal of the hydroxide addition must be slow relative to the forward breakdown of the tetrahedral intermediate. ... 

A. M. Selikhanovich, G. A. Chuprina, and A. N. Olejnikov. Reagent for treating drilling muds—contains acrylic polymer, sodium hydroxide, additional diethylene glycol, and water. Patent RU 2087515-C, 1997. 

For species 11 we will use the intrinsic barrier for hydroxide addition to trimethyl phosphate, G = 19 (calculated using rate and equilibrium data from reference 100) and assume the same value for the attack of hydroxide at sulfur on dimethyl sulfate. This (nonobservable) rate will be estimated using a Brpnsted type plot from the rate constants for diaryl sulfates (diphenyl sulfate,and bis p-nitrophenyl sulfate), estimated from the rate for phenyl dinitrophenyl sulfate,assuming equal contributions for the two nitro groups. This gives ftg = 0.95, and thus for dimethyl sulfate log k = 11.3... 

The chemistry of these phthalides has much in common with that of the compounds reviewed in the next chapter, i.e., the feMco-triarylmethanes, and in fact, the parent dyes of the two classes share the same basic chromophoric system. However, the latter are true redox systems, rather than pH indicators, and consequently have a different range of technical applications. The situation is complicated further in that the triarylmethane cationic dyes can also bleach at high pH, giving a hydroxide addition... 

Next, a series of runs was conducted to determine the effect of various alkali metal hydroxide additions along with the sponge nickel catalyst. The 50 wt. % sodium hydroxide and 50 wt. % potassium hydroxide caustic solution used in the initial test was replaced with an aqueous solution of the alkali metal hydroxide at the level indicated in Table 2. After the reaction number of cycles indicated in Table 2, a sample was removed for analysis. The conditions and results are shown in Table 2. The results reported in Table 2 show the level of 2° Amine in the product from the final cycle. The level of NPA in all of the mns was comparable to the level observed in the initial test. No significant levels of other impurities were detected. 

Addition of ammonium hydroxide and water were explored to evaluate their influence upon catalyst activity and selectivity. The data in this study suggest that there was little influence of ammonium hydroxide on reaction rate and selectivity. The data, however, were not sufficient to definitively define the role of these additives and investigation of these effects will be the subject of future exploration. Examination of Figure 3 may lead to the conclusion that water is actually harmful to the life of the catalyst but such a preliminary hypothesis is overly simplistic, acknowledging that the ammonium hydroxide additive comprises 70% water. 

The solution is stirred slowly and ca. 25 ml. of 2N cupric chloride solution is added slowly. The blue-green color of the cupric chloride is rapidly discharged and a brick red coloration occurs, followed by the precipitation of voluminous bright red crystals of the cuprous chelate of 2,3-diazabicyclo[2.2.1]hept-2-ene. The pH is adjusted to 5-6 by the addition of 5N ammonium hydroxide. Addition of 25 ml. of the cupric chloride solution followed by neutralization of the generated hydrochloric acid with 5iV ammonium hydroxide is repeated five times. The precipitate is collected by filtration and the filtrate is again treated with 25-ml. portions of cupric chloride solution and 5N ammonium hydroxide. The procedure is repeated until the filtrate is clear red at pH 3-4 and returns to a cloudy green at pH 6 with no further formation of precipitate (Note 5). 

Rubidium alum obtained by either method above is decomposed by treatment with alkali solutions for removal of aluminum and sulfate. Aluminum is precipitated as aluminum hydroxide. Addition of barium hydroxide to the filtrate removes sulfate, precipitating barium sulfate. Evaporation of the solution crystallizes rubidium as hydroxide. 

The carbonyl reactivity of pyrrole-, furan-, thiophene- and selenophene-2- and -3-carbaldehydes is very similar to that of benzaldehyde. A quantitative study of the reaction of Af-methylpyrrole-2-carbaldehyde, furan-2-carbaldehyde and thiophene-2-carbaldehyde with hydroxide ions showed that the difference in reactivity between furan- and thiophene-2-carbaldehydes was small but that both of these aldehydes were considerably more reactive to hydroxide addition at the carbonyl carbon than A-methylpyrrole-2-carbaldehyde (76JOC1952). Pyrrole-2-aldehydes fail to undergo Cannizzaro and benzoin reactions, which is attributed to mesomerism involving the ring nitrogen (see 366). They yield 2-hydroxymethylpyrroles (by NaBH4 reduction) and 2-methylpyrroles (Wolff-Kishner reduction). The IR spectrum of the hydrochloride of 2-formylpyrrole indicates that protonation occurs mainly at the carbonyl oxygen atom and only to a limited extent at C-5. 

These basic materials eventually are converted to their neutral salts by use of some alkaline material, such as sodium hydroxide. Additional, minor ingredients are added, e.g, sodium silicate or magnesium sulfate, to control alkalinity, odor, and aging stability. 

A commercially important mixed addition involves ethanal and an excess of methanal in the presence of calcium hydroxide. Addition occurs three times and the resulting trihydroxymethylethanal (which has no a hydrogens) undergoes a crossed Cannizzaro reaction (see Exercise 16-33) with more methanal to give a tetrahydroxy alcohol known as pentaerythritol ... 

Fig 11. Conversion of cetane versus lithium hydroxide addition for several cracking catalysts A, 19% AljOj/81% SiOs. B, 31% MgO/69% SiO, C, 12% BjO,/88% Al,Oa (48). (Reprinted with permission of the American Chemical Society.)... 

Hydroxide. Addition of acetic acid to a vessel contaminated with potassium hydroxide caused eruption of the acid.10... 

Sodium Hydroxide. Addition of liquid chlorine to 20% sodium hydroxide solution resulted in a violent reaction.31... 

Photolysis of 3-substituted pyridinium salt 234 in aqueous base provides the highly functionalized bicyclic aziridine 236, albeit in low yield (20%) <2005JOC5618>. Fortunately, the two regioisomers can be separated chromatographically. The reaction presumably proceeds through indiscriminant hydroxide addition onto an intermediate allylic cation 235. Compound 236 can be carried on to the desired acetamidocyclopentene derivative 237 in three steps and 80% yield (Scheme 42). 

Procedure Fill the titrator buret with the 0.05 N Sodium Hydroxide solution, and following the manufacturer s instructions, set the temperature to 30° and the pH set point to 7.0. Transfer 15.0 mL of the Substrate Emulsion to the titration cell, and add a small stirrer bar. Add 1.0 mL of the diluted Sample Preparation, and actuate the titrator. Record the rate of 0.05 N Sodium Hydroxide addition. Stop the titration after a constant (linear) rate of addition has been observed for 5 min. Determine the addition rate, in milliliters per minute, from the linear portion of the recording and record this value as R. 

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