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This is a list of unsolved problems in chemistry. Problems in chemistry are considered unsolved when an expert in the field considers it unsolved or when several experts in the field disagree about a solution to a problem.
organic, inorganic chemicals, proteins CASNo paid access only 130,000,000 ScrubChem scraped from PubChem "ScrubChem". 2,282,992 SDBS: Spectral Database for Organic Compounds National Institute of Advanced Industrial Science and Technology (AIST), Japan Organic compounds Spectra:IR Raman MASS ESR 1 H NMR 13 C NMR SDBS No curated "SDBS". 34,000
The Curtin–Hammett principle is a principle in chemical kinetics proposed by David Yarrow Curtin and Louis Plack Hammett.It states that, for a reaction that has a pair of reactive intermediates or reactants that interconvert rapidly (as is usually the case for conformational isomers), each going irreversibly to a different product, the product ratio will depend both on the difference in ...
In organic chemistry, the Hammett equation describes a linear free-energy relationship relating reaction rates and equilibrium constants for many reactions involving benzoic acid derivatives with meta- and para-substituents to each other with just two parameters: a substituent constant and a reaction constant.
The rule states that with the addition of a protic acid HX or other polar reagent to an asymmetric alkene, the acid hydrogen (H) or electropositive part gets attached to the carbon with more hydrogen substituents, and the halide (X) group or electronegative part gets attached to the carbon with more alkyl substituents. This is in contrast to ...
For that, a specific task in science was chosen: help organic chemists in identifying unknown organic molecules, by analyzing their mass spectra and using knowledge of chemistry. [1] It was done at Stanford University by Edward Feigenbaum , Bruce G. Buchanan , [ 2 ] Joshua Lederberg , and Carl Djerassi , along with a team of highly creative ...
In organic chemistry, Hückel's rule predicts that a planar ring molecule will have aromatic properties if it has 4n + 2 π-electrons, where n is a non-negative integer. The quantum mechanical basis for its formulation was first worked out by physical chemist Erich Hückel in 1931.
It is commonly used for the identification of organic compounds from electron ionization mass spectrometry. [ 3 ] [ 4 ] Organic chemists obtain mass spectra of chemical compounds as part of structure elucidation and the analysis is part of many organic chemistry curricula.