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Science. 309 (125th Anniversary). 1 July 2005. Unsolved Problems in Nanotechnology: Chemical Processing by Self-Assembly - Matthew Tirrell - Departments of Chemical Engineering and Materials, Materials Research Laboratory, California NanoSystems Institute, University of California, Santa Barbara [No doc at link, 20 Aug 2016]
A reversible reaction is a reaction in which the conversion of reactants to products and the conversion of products to reactants occur simultaneously. [1]+ + A and B can react to form C and D or, in the reverse reaction, C and D can react to form A and B.
Dynamic kinetic resolution in chemistry is a type of kinetic resolution where 100% of a racemic compound can be converted into an enantiopure compound. It is applied in asymmetric synthesis . Asymmetric synthesis has become a much explored field due to the challenge of creating a compound with a single 3D structure. [ 1 ]
Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur. The substance (or substances) initially involved in a chemical reaction are called reactants or reagents.
The transformation can be described using the Avrami equation as a plot of vs , yielding a straight line. Transformations are often seen to follow a characteristic s-shaped, or sigmoidal, profile where the transformation rates are low at the beginning and the end of the transformation but rapid in between.
Cascade reactions are often key steps in the efficient total synthesis of complex natural products. The key step in Heathcock's synthesis of dihydroprotodaphniphylline features a highly efficient cascade involving two aldehyde/amine condensations, a Prins-like cyclization, and a 1,5-hydride transfer to afford a pentacyclic structure from an acyclic starting material.
The Cram's rule of asymmetric induction named after Donald J. Cram states In certain non-catalytic reactions that diastereomer will predominate, which could be formed by the approach of the entering group from the least hindered side when the rotational conformation of the C-C bond is such that the double bond is flanked by the two least bulky groups attached to the adjacent asymmetric center. [3]
Phase transitions (phase changes) that help describe polymorphism include polymorphic transitions as well as melting and vaporization transitions. According to IUPAC, a polymorphic transition is "A reversible transition of a solid crystalline phase at a certain temperature and pressure (the inversion point) to another phase of the same chemical composition with a different crystal structure."