Association reaction mechanism

Selection of curing agent and associated reaction mechanism... 

Let us now turn our attention to Au, where a full catalytic cycle could unambiguously be observed by measuring the kinetics of the process at different temperatures [29]. At room temperature, oxygen reacts by a straightforward association reaction mechanism with the dimer anion, as determined from the measured product ion concentration as a function of the reaction time, and the negative dependence of the reaction rate with temperature ... 

The operations involved in the dissociative and associative reaction mechanisms for octahedral complexes. Two different shapes for intermediates are based on known shapes for these coordination numbers. 

Dissociative and associative reaction mechanisms involve two-step pathways and an intermediate. 

Using a combination of several in situ characterization methods to look at working catalysts, and catalytic reactions, from different perspectives, represents a substantial step toward elucidating the chemistry of catalyst materials and associated reaction mechanisms. 

The current density measured from the rotating electrode is contributed by both the current densities of electrode electron-transfer reaction and the reactant diffusion. In order to obtain the kinetic parameters of these two processes and their associated reaction mechanisms based on the experiment data, both the theories of electrode electron-transfer reaction and reactant diffusion should be studied and understood. In this chapter, the general theories for electrode kinetics of electron-transfer reaction and reactant diffusion will be given in a detailed level, and we hope these theories will form a solid knowledge for a continuing study in the following chapters of this book. 

In spite of frequent discussions on the validity of the concept of aromaticity, the term aromatic compound is still widely used. For the wide range of industrially produced aromatics, the definition of aromaticity based on Hiickel s rule and the associated reaction mechanisms is perfectly adequate. 

The methoxy species formed by the dissociation of methanol can react with a second methanol molecule to give dimethyl ether and a proton. This is termed the alkoxy intermediate for the consecutive direct reaction mechanism. Alternative reaction paths exist which can be described as associative reaction mechanisms in which the product of an association reaction is formed without the formation of an alkoxy intermediate species . For two coadsorbed methanol molecules, the most stable adsorption mode does... 

The creation of a new bond between two different molecules or molecular fragments through consecutive reaction steps is typically called a direct reaction mechanism. In each individual reaction step, a chemical bond between the molecule or molecular fragment and the catalyst surface is formed. The molecular fragments bonded to the catalyst surface can subsequently react with a second adsorbed molecule. In an associative reaction mechanism, a cluster of at least two molecules adsorbs at the reaction center. Bond formation and cleavage reaction, now occur as a single event within the adsorbate cluster consisting of several molecules. This is assisted by transient chemical bond formation with the catalyst surface. 

Alcohol (ROH) exchange with esters VO(OR)3 has been monitored by n.m.r. line-broadening techniques, for R = Pr , Pr, Bu , and n-pentyl. Activation enthalpies vary between 21.4 and 32.7 kJ mol, activation entropies between —129 and -150 JK" mol. These negative values are strongly suggestive of a predominantly associative reaction mechanism. ... 

The photocatalytic action of Ti02 (and other semicOTiductors) is initiated by the photo-production of excess electrons in the conducticni band (e cb) and holes in the valence band (h%b). The electron reduces the oxygen or the nitrogen dioxide while the hole oxidizes water vapor. The associated reactions mechanism could be [5]... 

This statement, however, has been challenged [41] because little resemblance of that spectrum to the literature spectrum [42] was found.An isomeric mixture of brominated biphenyls and an associated reaction mechanism were proposed instead [41]. It has been pointed out [43] that authentic brominated biphenyls have not been available for comparison. 

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