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In chemistry, a reaction step of a chemical reaction is defined as: "An elementary reaction, constituting one of the stages of a stepwise reaction in which a reaction intermediate (or, for the first step, the reactants) is converted into the next reaction intermediate (or, for the last step, the products) in the sequence of intermediates between reactants and products". [1]
Usage of monomer in the reaction: Rapid loss of monomer early in the reaction: Some monomer remains even at long reaction times Reaction steps: Similar steps repeated throughout reaction process: Different steps operate at different stages of mechanism (i.e. initiation, propagation, termination, and chain transfer) Average molecular weight
This type of polymerization is described as "chain" or "chain-growth" because the reaction mechanism is a chemical chain reaction with an initiation step in which an active center is formed, followed by a rapid sequence of chain propagation steps in which the polymer molecule grows by addition of one monomer molecule to the active center in ...
In chemistry, chain propagation (sometimes just referred to as propagation) is a process in which a reactive intermediate is continuously regenerated during the course of a chemical chain reaction. For example, in the chlorination of methane , there is a two-step propagation cycle involving as chain carriers a chlorine atom and a methyl radical ...
In chain-growth polymerization the propagation step is the addition of a monomer to the growing chain. The word kinetic is added to chain length in order to distinguish the number of reaction steps in the kinetic chain from the number of monomers in the final macromolecule, a quantity named the degree of polymerization. In fact the kinetic ...
The termination steps of free radical polymerization steps are of two types: recombination and disproportionation. [2] In a recombination step, two growing chain radicals (denoted by •) form a covalent bond in a single stable molecule. For the example of a vinyl polymer,
The C represents a chemical reaction which can be any elementary reaction step and is often called a "following" reaction. In coordination chemistry common C steps which "follow" electron transfer are ligand loss and association. The ligand loss or gain is associated with a geometric change in the complexes coordination sphere.
The dialkyl chlorophosphates formed are often too reactive to be isolated, though. For this reason, the synthesis of phosphates or phosphoramidates can follow the Atherton-Todd reaction in the presence of alcohols or amines. The following equation gives an overview over the Atherton-Todd reaction using the reactant dimethyl phosphite as an example: