Reaction dependence

The selection of reactor pressure for vapor-phase reversible reactions depends on whether there is a decrease or increase in the number of moles and whether there is a system of single or multiple reactions. 

Bucherer reaction Bucherer discovered that the interconversion of 2-naphthol and 2-naphthylamine through the action of alkali and ammonia could be facilitated if the reaction was carried out in the presence of (HSO3]" at about 150 C. This reaction is exceptional for the ease with which an aromatic C —OH bond is broken. It is not of general application, it is probable that the reaction depends upon the addition of [HSO3]" to the normally unstable keto-form of 2-naphthol, and subsequent displacement of —OH by —NH2. 

Elementary reactions are characterized by their moiecuiarity, to be clearly distinguished from the reaction order. We distinguish uni- (or mono-), hi-, and trimoiecuiar reactions depending on the number of particles involved in the essential step of the reaction. There is some looseness in what is to be considered essential but in gas kinetics the definitions usually are clearcut through the number of particles involved in a reactive collision plus, perhaps, an additional convention as is customary in iinimolecular reactions. 

The reaction depends upon the catalytic influence of the cyanide ion, the mechanism being probably as follows ... 

The success of the last reaction depends upon the inertness of the ester carbonyl groups towards the organocadmium compound with its aid and the use of various ester acid chlorides, a carbon chain can be built up to any reasonable length whilst retaining a reactive functional group (the ester group) at one end of the chain. Experimental details are given for l-chloro-2-hexanone and propiophenone. The complete reaction (formation of ketones or keto-esters) can be carried out in one flask without isolation of intermediates, so that the preparation is really equivalent to one step. 

The relative extents to which enforced hydrophobic interactions and hydrogen bonding influence the rate of the Diels-Alder reaction depends on the particular reaction under study". 

Nitration can be effected under a wide variety of conditions, as already indicated. The characteristics and kinetics exhibited by the reactions depend on the reagents used, but, as the mechanisms have been elucidated, the surprising fact has emerged that the nitronium ion is preeminently effective as the electrophilic species. The evidence for the operation of other electrophiles will be discussed, but it can be said that the supremacy of one electrophile is uncharacteristic of electrophilic substitutions, and bestows on nitration great utility as a model reaction. 

The observation of nitration in nitromethane fully dependent on the first power of the concentration of aromatic was made later. The rate of reaction of /)-dichlorobenzene ([aromatic] = 0-2 mol [HNO3] = 8-5 mol 1 ) obeyed such a law. The fact that in a similar solution 1,2,4-trichlorobenzene underwent reaction according to the same kinetic law, but about ten times slower, shows that under first-order conditions the rate of reaction depends on the reactivity of the compound. 

The observation of nitration nitrosation for mesitylene is important, for it shows that this reaction depends on the reactivity of the aromatic nucleus rather than on any special properties of phenols or anilines. 

Success of the reactions depends considerably on the substrates and reaction Conditions. Rate enhancement in the coupling reaction was observed under high pressure (10 kbar)[l 1[. The oxidative addition of aryl halides to Pd(0) is a highly disfavored step when powerful electron donors such as OH and NHt reside on aromatic rings. Iodides react smoothly even in the absence of a... 

Carbonylation of propargylic carbonates proceeds under mild neutral conditions (50 °C, I-10 atm) using Pd(OAc)2 and Ph ,P as a catalyst, yielding the 2,3-alkadienoates 18 in good yields[9,10]. The 2.3-alkadienoates isomerize to 2,4-dienoates during the reaction depending on the solvents and reaction time. 2-Decynyl methyl carbonate is converted into methyl 2-heptyl-2,3-butadienoate (19) in 82% yield. 

The percentage of these various compounds during the reaction depends upon the experimental conditions. 

Because the carbon-halogen bond breaks m the slow step the rate of the reaction depends on the leaving group Alkyl iodides have the weakest carbon-halogen bond and are the most reactive alkyl fluorides have the strongest carbon-halogen bond and are the least reactive... 

The stereoselectivity of this reaction depends on how the alkene approaches the catalyst surface As the molecular model m Figure 6 3 shows one of the methyl groups on the bridge carbon lies directly over the double bond and blocks that face from easy access to the catalyst The bottom face of the double bond is more exposed and both hydrogens are transferred from the catalyst surface to that face... 

The foregoing conclusion does not mean that the rate of the reaction proceeds through Table 5.1 at a constant value. The rate of reaction depends on the concentrations of reactive groups, as well as on the reactivities of the latter. Accordingly, the rate of the reaction decreases as the extent of reaction progresses. When the rate law for the reaction is extracted from proper kinetic experiments, specific reactions are found to be characterized by fixed rate constants over a range of n values. 

The extent of such reactions depends on the monomer structure as well as the temperature and the solvent. 

This reaction has a positive free energy of 422.2 kj (100.9 kcal) at 25°C and hence energy has to be suppHed in the form of d-c electricity to drive the reaction in a net forward direction. The amount of electrical energy required for the reaction depends on electrolytic cell parameters such as current density, voltage, anode and cathode material, and the cell design. 

AH higher a-olefins, in the presence of Ziegler-Natta catalysts, can easily copolymerise both with other a-olefins and with ethylene (51,59). In these reactions, higher a-olefins are all less reactive than ethylene and propylene (41). Their reactivities in the copolymerisation reactions depend on the sise and the branching degree of their alkyl groups (51) (see Olefin polya rs, linear low density polyethylene). 

Oxidation. There are 10 types of oxidative reactions in use industriaHy (80). Safe reactions depend on limiting the concentration of oxidi2ing agents or oxidants, or on low temperature. The foUowing should be used with extreme caution salts of permanganic acid hypochlorous acid and salts sodium... 

In certain cases, alkanolamines function as reduciag agents. For example, monoethanolamine reduces anthraquiaone to anthranols, acetone to 2-propanol, and azobenzene to aniline (17). The reduction reaction depends on the decomposition of the alkan olamine iato ammonia and an aldehyde. Sinulady, diethan olamine converts o-chloronitrobenzene to 2,2 -dichloroazobenzene and y -dinitrobenzene to 3,3 -diamiQoazobenzene. 

The speed of the reaction depends both on the metal and on the alcohol, increasing as electropositivity iacreases and decreasiag with length and branching of the chain. Thus sodium reacts strongly with ethanol, but slowly with tertiary butyl alcohol. The reaction with alkaU metals is sometimes carried out ia ether, ben2ene, or xylene. Some processes use the metal amalgam or hydride iastead of the free metal. Alkaline earth metals and aluminum are often covered with an oxide film which hinders the reaction. 

Oxidation. Aromatic amines can undergo a variety of oxidation reactions, depending on the oxidizing agent and the reaction conditions. For example, oxidation of aniline can lead to formation of phenyUiydroxylamine, nitrosobenzene, nitrobenzene, azobenzene, azoxybenzene or -benzoquinone. Oxidation was of great importance in the early stages of the development of aniline and the manufacture of synthetic dyes, such as aniline black and Perkin s mauve. 

Reactions Depending on Both Amino and Carboxyl Groups. 

The total number of reactions depends on the number of constituents present in the hydrocarbon feedstock. As many as 2000 reactions can occur simultaneously. 

Syntheses of quiaones often iavolve oxidation because this is the only completely general method (103). Thus, ia several iastances, quiaones are the reagents of choice for the preparation of other quiaones. Oxidation has been especially usefiil with catechols and hydroquiaones as starting materials (23,24). The preparative utility of these reactions depends largely on the relative oxidation potentials of the quiaones (104,105). 

Soap as used in personal cleansing products has a long safe history of use. Modem soaps have been specifically formulated to be compatible with skin and to be used on a daily basis with minimal side effects. Excessive use of soap for skin cleansing can dismpt the natural barrier function of skin through the removal of skin oils and dismption of the Hpid bdayer in skin. This can result in imperfect desquamation or a dry appearance to skin and cause an irritation response or erythema, ie, reddening of the skin. Neither of these is a permanent response and the eHcitation of this type of skin reaction depends on the individual s skin type, the product formulation, and the frequency of use. 

Zirconium alkoxides readily hydrolyze to hydrous zirconia. However, when limited amounts of water are added to zirconium alkoxides, they partially hydrolyze in a variety of reactions depending on the particular alkoxide (222). Zirconium tetraisopropoxide [2171 -98-4] reacts with fatty acids to form carboxjiates (223), and with glycols to form mono- and diglycolates (224). 

The anode reaction depends on the electrolyte used, but the charge-transfer step is... 

The reaction involves the nucleophilic attack of a peracid anion on the unionized peracid giving a tetrahedral diperoxy intermediate that then eliminates oxygen giving the parent acids. The observed rate of the reaction depends on the initial concentration of the peracid as expected in a second-order process. The reaction also depends on the stmcture of the peracid (specifically whether the peracid can micellize) (4). MiceUization increases the effective second-order concentration of the peracid because of the proximity of one peracid to another. This effect can be mitigated by the addition of an appropriate surfactant, which when incorporated into the peracid micelle, effectively dilutes the peracid, reducing the rate of decomposition (4,90). 

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