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  2. List of unsolved problems in chemistry - Wikipedia

    en.wikipedia.org/wiki/List_of_unsolved_problems...

    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.

  3. List of chemical databases - Wikipedia

    en.wikipedia.org/wiki/List_of_chemical_databases

    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 Serum Metabolome Database: The Metabolomics Innovation Centre: found in blood serum "Serum Metabolome DB". 4,651 Solvent Selection Tool ACS Green Chemistry ...

  4. Fragmentation (mass spectrometry) - Wikipedia

    en.wikipedia.org/wiki/Fragmentation_(mass...

    These reactions are well documented over the decades and fragmentation patterns are useful to determine the molar weight and structural information of unknown molecules. [ 1 ] [ 2 ] Fragmentation that occurs in tandem mass spectrometry experiments has been a recent focus of research, because this data helps facilitate the identification of ...

  5. Mass spectral interpretation - Wikipedia

    en.wikipedia.org/wiki/Mass_spectral_interpretation

    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.

  6. Internal standard - Wikipedia

    en.wikipedia.org/wiki/Internal_standard

    In NMR spectroscopy, e.g. of the nuclei 1 H, 13 C and 29 Si, frequencies depend on the magnetic field, which is not the same across all experiments. Therefore, frequencies are reported as relative differences to tetramethylsilane (TMS), an internal standard that George Tiers proposed in 1958 and that the International Union of Pure and Applied Chemistry has since endorsed.

  7. Bromine test - Wikipedia

    en.wikipedia.org/wiki/Bromine_test

    In organic chemistry, the bromine test is a qualitative test for the presence of unsaturation (carbon-to-carbon double or triple bonds), phenols and anilines. An unknown sample is treated with a small amount of elemental bromine in an organic solvent, being as dichloromethane or carbon tetrachloride. Presence of unsaturation and/or phenol or ...

  8. List of organic reactions - Wikipedia

    en.wikipedia.org/wiki/List_of_organic_reactions

    Cadiot–Chodkiewicz coupling; Cadogan-Sundberg indole synthesis; Camps quinoline synthesis; Cannizzaro reaction; Carbohydrate acetalisation; Carbonyl reduction

  9. Hammett equation - Wikipedia

    en.wikipedia.org/wiki/Hammett_equation

    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.