Stability to hydrolysis

Hydrolysis of an organometallic compoimd often involves nucleophilic attack by water, and hence is facilitated by the presence of empty low-lying orbitals on the metal atom. In agreement with this, the organic derivatives of the elements of Groups lA and HA, and of Zn, Cd, Al, Ga and In are readily hydrolysed. The rate of hydrolysis is dependent on the 

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Monobasic aluminum acetate is dispensed as a 7% aqueous solution for the topical treatment of certain dermatological conditions, where a combination of detergent, antiseptic, astringent, and heat-dispersant effects are needed (12). The solution, diluted with 20—40 parts water, is appHed topically to the skin and mucous membranes as a wet dressing (13). Burrow s solution, prepared from aluminum subacetate solution by the addition of a specific amount of acetic acid, is also used as a topical wet dressing. Standards of purity and concentration have been estabHshed for both pharmaceutical aluminum acetate solutions (13). Each 100 mL of aluminum subacetate solution yields 2.30—2.60 g of aluminum oxide and 5.43—6.13 g of acetic acid upon hydrolysis. For the Burow s solution, each 100 mL yields 1.20—1.45 g of aluminum oxide and 4.25—5.12 g of acetic acid. Both solutions may be stabilized to hydrolysis by the addition of boric acid in amounts not to exceed 0.9% and 0.6% for the subacetate and Burow s solutions, respectively (13). 

Without a doubt, tetrafluoroborate and hexafluorophosphate ionic liquids have shortcomings for larger-scale technical application. The relatively high cost of their anions, their insufficient stability to hydrolysis for long-term application in contact with water (formation of corrosive and toxic HF during hydrolysis ), and problems related to their disposal have to be mentioned here. New families of ionic liquid that should meet industrial requirements in a much better way are therefore being developed. FFowever, these new systems will probably be protected by state of matter patents. 

The author anticipates that the further development of transition metal catalysis in ionic liquids will, to a significant extent, be driven by the availability of new ionic liquids with different anion systems. In particular, cheap, halogen-free systems combining weak coordination to electrophilic metal centers and low viscosity with high stability to hydrolysis are highly desirable. 

Much of the recent literature relates to BfVbridged Co" cobaloximes based on dimethyl (89) or diphenyl glyoxime (104).110 The BfVbridged cobaloximes (e.g. 89) show greater stability to hydrolysis than analogous H-bridged species (e.g. 88). The diphenylglyoxime complexes (104) show enhanced air and hydrolytic stability... 

Bistline et al. [59] determined the stability to hydrolysis of sodium hexa-decanol, hexadecanol ether (2 EO), octadecanol ether (2 EO), and octadecanol... 

The formation of a strong intramolecular dative P—B bond in the hydro-borylation reaction of diallylphenylphosphine with triethylaminophenyl-borane results in a bicyclic product, l-borata-5-phosphoniabi-cyclo[3,3,0]octane (204) [Eq. (145)] (64JA5045). The presence of the dative bond in this compound is indicated by an NMR study and by its stability to hydrolysis and oxidation. 

How is DNA suitable as a carrier of genetic information While we do not entirely understand them, several features are present in DNA. First, because of the double-stranded nature and mode of replication, retention is enhanced. Second, DNA is particularly stable within both cellular and extracellular environments, and has a good stability to hydrolysis within an aqueous environment. Plant and animal DNAs have survived thousands of years. Using polymerase chain reactions (PCRs) we can reconstruct DNA segments allowing comparisons to modern DNA. 

Polyethersulfones 200 Good chemical resistance and stability to hydrolysis... 

The principal constituents of rosin (qv) are abietic and related acids. Tall oil (qv) is a mixture of unsaturated fatty and alicydic acids of the abietic family. Refined tall oil may be high in rosin acids or unsaturated acids, depending on the refining process. Ethoxylates of rosin acids, eg, dehydro abietic acid, are similar to fatty acid ethoxylates in surfactant properties and manufacture, except for their stability to hydrolysis. No noticeable decomposition is observed when a rosin ester of this type is boiled for 15 min in 10% sulfuric acid or 25% sodium hydroxide (90). Steric hindrance of the carboxylate group associated with the alicyclic moiety has been suggested as the cause of this unexpectedly great hydrolytic stability. 

Sulfation is the generation of an oxygen sulfur(IV) bond, where the oxygen is attached to the carbon backbone, in the most controlled manner possible, using some form of sulfur dioxide moiety. When sulfating alcohols, the reaction is strongly exothermic, Examples of feedstocks for such a process include alkenes, alcohols, or phenols. Unlike the sulfonates, which exhibit excellent stability to hydrolysis, the alcohol sulfates are readily susceptible to hydrolysis in acidic media, The sulfation of fatty alcohols and fatty polyalkoxylates has produced a substantial body of commercial detergents and emulsifiers. 

The molecular derivatives of platinum group metals are usually rather well soluble in organic solvents and volatile in vacuum. At normal pressure they demonstrate very low thermal stability and easily decompose producing fine metal powders. This decomposition occurs more easily for the derivatives of branched radicals as it is based on a P-hydrogen elimination process. An important feature of the chemical behavior of these alkoxide complexes is their rather high stability to hydrolysis. Some derivatives can even form outer sphere hydrates when reacted with water in organic solvents. This stability to hydrolysis can at least partially be due to the kinetic inertness of the complexes of this group. 

Triisopropylsilyl ethers iPr3Si-OR TIPS-OR - more stabile to hydrolysis than TMS... 

Compared to salts, acetyl acetonates offer better solubility in organic solvents and better stability to hydrolysis. They are likely to be less reactive than salts, because complexes of either iron or copper in their highest oxidation state with acetyl acetone are more stabile than at the lower oxidation state. 

He encouraged the use of isopropyl acetate (b.p. 89°C) instead of ethyl acetate (b.p. 77°C) because of its reduced water solubility and greater stability to hydrolysis. He preceded the phase transfer catalysis era using detergents to speed reaction rates and increase yields. His bag of tricks, as he would whimsically refer to his armory of techniques, was an eye opener for his more conventional disciples. 

As implied by their description, nonmetallized azo reds do not contain a precipitating metal cation and as such offer increased stability to hydrolysis in highly acidic or alkaline environments as compared to the metallized azo reds previously covered. 

Pteridine Studies. Part III. The Solubility and Stability to Hydrolysis of Pteri dines. 

Altering the substituents on the Cp rings also has radical effects on a variety of physical properties, including solid-state geometries, solubility, stability to hydrolysis, oxidation, and ligand extrusion, and others. 

DMU is highly reactive finish baths have to be used in a few hours Low stability to hydrolysis, low durability to laundering High chlorine retention... 

Better stability to hydrolysis and better washing durability than U/F products... 

Better stability to hydrolysis Fewer dyestuff restrictions, including brilliant shades... 

The stability to hydrolysis of lupanine (LXXIII) has been thoroughly studied [66, 67). Its equilibrium with lupaninic acid (LXXIV) in 0.2 N hydrochloric acid is 11.8% in 10 N hydrochloric acid 0%, and in 1 N potassium hydroxide 90% in favor of the acid. The equilibrium is achieved eight times more rapidly in acid than in alkaline solution. 

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