Sodium and Potassium Bases

Sodium and potassium bases are in the high-solubility category of neutralizing agents (Table 12.7). Their major advantage is ease of application. The most common high- 

Sodium hydroxide (NaOH) Very high 12 High-suspension solids 

Sodium carbonate (Na2C03) Very high -12 High-suspension solids 

Sodium bicarbonate (NaHCOj) Very high 8.3 High-suspension solids 

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The diene monomers give predominantly 1,4-polymers in hydrocarbon solvents if polymerized using lithium-based initiation. Isoprene, under these conditions, gives a predominantly cis-1,4 polymer but with butadiene the proportions of cis- and frans-1,4 are fairly evenly distributed. Once ain this phenomenon is characteristic of lithium compounds sodium- and potassium-based initiation gives mixed structures even in hydrocarbon solvents. Polymerization in polar solvents such as tetrahydrofuran leads to largely 3,4-polyisoprene or 1,2-butadiene with... 

Fractional crystallisation is based on favorable solubiUty relationships. Potassium chloride is much more soluble at elevated temperatures than at ambient temperatures in solutions that are saturated with sodium and potassium chlorides. Sodium chloride is slightly less soluble at elevated temperatures than at ambient temperatures in solutions that are saturated with KCl and NaCl. Working process temperatures are usually 30—110°C. The system,... 

Properties. Most of the alloys developed to date were intended for service as fuel cladding and other stmctural components in hquid-metal-cooled fast-breeder reactors. AHoy selection was based primarily on the following criteria corrosion resistance in Hquid metals, including lithium, sodium, and NaK, and a mixture of sodium and potassium strength ductihty, including fabricabihty and neutron considerations, including low absorption of fast neutrons as well as irradiation embrittlement and dimensional-variation effects. Alloys of greatest interest include V 80, Cr 15, Ti 5... 

With the exception of tall oil and castor oil acids, and acids used for sodium and potassium soaps, Tables 3, 4, and 5 provide detailed production and disposition information on the U.S. triglyceride-based fatty acids. These data show a 2—3%/yr growth rate between 1985 and 1990, virtually in line with world projections, with the most significant growth occurring in the stearic and coconut acid segments. 

If the equilibrium were established rapidly, reduction of the free ketone as it formed would result in a substantial loss of product. Lithium enolates are more covalent in character than are those of sodium and potassium and consequently are the least basic of the group. This lower thermodynamic basicity appears to be paralleled by a lower kinetic basicity several workers have shown that lithium enolates are weaker bases in the kinetic sense than are those of sodium and potassium." As noted earlier, conjugated enones... 

In IC this problem of electrolyte background is overcome by means of eluant suppression. Thus in the above example of sodium and potassium analysis, if the effluent from the separating column is passed through a strong base anion exchange resin in the hydroxide form (suppressor column) the following two processes occur ... 

In the Phadebas TM amylase test (72) (Pharmacia Labs) the substrate was a water insoluble cross-TTnked blue starch in tablet form which also contains some inert ingredients, sodium and potassium phosphate buffer salts and sodium chloride. This polymer was hydrolyzed by amylase into water soluble blue starch fragments. After centrifugation the absorbance of the blue supernatant was proportional to the activity of amylase present in the test samples. The day to day variation on a quality control serum had a coefficient of variation of 2.7% based on 30 days of data in our laboratory. The method is simple, reproducible and uses microquantities of serum. 

Ester enolates are somewhat less stable than ketone enolates because of the potential for elimination of alkoxide. The sodium and potassium enolates are rather unstable, but Rathke and co-workers found that the lithium enolates can be generated at -78° C.69 Alkylations of simple esters require a strong base because relatively weak bases such as alkoxides promote condensation reactions (see Section 2.3.1). The successful formation of ester enolates typically involves an amide base, usually LDA or LiHDMS, at low temperature.70 The resulting enolates can be successfully alkylated with alkyl bromides or iodides. HMPA is sometimes added to accelerate the alkylation reaction. 

The Vaughan-Williams classification of antiarrhythmic drugs has been criticized for a number of reasons. The classification is based on the effects of drugs on normal, rather than diseased, myocardium. In addition, many of the drugs may be placed into more than one class. For example, the class IA drugs prolong repolarization/refractoriness, either via the parent drug8,9 or an active metabolite,10 and therefore also maybe placed in class III. Sotalol is also a 3-blocker, and therefore fits into class II. Amiodarone inhibits sodium and potassium channels, is a non-competitive inhibitor of 3-receptors, and inhibits calcium... 

Concentration limits for chloride and acetate in PN typically are linked to limitations for sodium and potassium. The usual ratio of chloride acetate in PN is about 1 1 to 1.5 1. Chloride and acetate primarily play a role in acid-base balance. Acetate is converted to bicarbonate at a 1 1 molar ratio. This conversion appears to occur mostly outside the liver. Bicarbonate never should be added to or coinfused with PN solutions. This can lead to the release of carbon dioxide and potentially result in the formation of calcium or magnesium carbonate (very insoluble salts). 

The preparation of salts of organic compounds is one of the most important tools available to the for-mulator. Compounds for both IM and IV solutions may require high solubility in order for the drug to be incorporated into acceptable volumes for bolus administration (see Table 1). Sodium and potassium salts of weak acids and hydrochloride and sulfate salts of weak bases are widely used in parenterals requiring highly soluble compounds, based on their overall safety and history of clinical acceptance. 

Treatment of all four diasteromers of 72 with sodium or potassium bases yielded stilbenes with high stereoselectivity (Scheme 15) <2003T255>. Two of the diastereomers gave rise to some retro-aldol products. In two cases, hexacoordinate species were identified by the upheld 31P chemical shift (5—112 ppm). It was noted that phosphoranes that ring-closed to form hexacoordinate tricyclic species were the ones that did not undergo the retro-aldol reaction to produce aldehydes. The ring closure was disfavored for intermediates with steric repulsion between trifluoromethyl and phenyl groups. 

Sodium and potassium alkoxides are often used as bases in organic synthesis. 

Dioctyl sebacate (DOS) with relative permittivity e of 3.9 and 2-nitrophenyl octyl ether (NPOE) with e = 23.9 are the traditionally used sensor membrane plasticizers. The choice of a plasticizer always depends on a sensor application. Thus, NPOE appears to be more beneficial for divalent ions due to its higher polarity, but for some cases its lipophilicity is insufficient. Furthermore, measurements with NPOE-plasticized sensors in undiluted blood are complicated by precipitation of charged species (mainly proteins) on the sensor surface, which leads to significant potential drifts. Although calcium selectivity against sodium and potassium for NPOE-based membranes is better by two orders of magnitude compared to DOS membranes, the latter are recommended for blood measurements as their lower polarity prevents protein deposition [92],... 

The cyclisation of phenylglycine (4) to indoxyl (2) requires heating in the presence of strong bases (Scheme 4.1). The best results are obtained using sodamide at temperatures near 190 °C, preferably mixed with sodium and potassium hydroxides which give a eutectic of low melting point. 

The broader subject of the interaction of stable carbenes with main-group compounds has recently been reviewed. Accordingly, the following discussion focuses on metallic elements of the s and p blocks. Dimeric NHC-alkali adducts have been characterized for lithium, sodium, and potassium. For imidazolin-2-ylidenes, alkoxy-bridged lithium dimer 20 and a lithium-cyclopentadienyl derivative 21 have been reported. For tetrahydropyrimid-2-ylidenes, amido-bridged dimers 22 have been characterized for lithium, sodium, and potassium. Since one of the synthetic approaches to stable NHCs involves the deprotonation of imidazolium cations with alkali metal bases, the interactions of alkali metal cations with NHCs are considered to be important for understanding the solution behavior of NHCs. 

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