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  2. List of character tables for chemically important 3D point ...

    en.wikipedia.org/wiki/List_of_character_tables...

    These groups are characterized by i) an n-fold proper rotation axis C n; ii) n 2-fold proper rotation axes C 2 normal to C n; iii) a mirror plane σ h normal to C n and containing the C 2 s. The D 1h group is the same as the C 2v group in the pyramidal groups section. The D 8h table reflects the 2007 discovery of errors in older references. [4]

  3. Neighbouring group participation - Wikipedia

    en.wikipedia.org/wiki/Neighbouring_group...

    A classic example of NGP is the reaction of a sulfur or nitrogen mustard with a nucleophile, the rate of reaction is much higher for the sulfur mustard and a nucleophile than it would be for a primary or secondary alkyl chloride without a heteroatom. [5] Ph−S−CH 2 −CH 2 −Cl reacts with water 600 times faster than CH 3 −CH 2 −CH 2 ...

  4. Meso compound - Wikipedia

    en.wikipedia.org/wiki/Meso_compound

    One of the two meso isomers of 1,2,3,4-tetrafluorospiropentane, with S 4 symmetry. Since a meso isomer has a superposable mirror image, a compound with a total of n chiral centers cannot attain the theoretical maximum of 2 n stereoisomers if one of the stereoisomers is meso. [4] A meso isomer need not have a mirror plane.

  5. 1,2-Dichloropropane - Wikipedia

    en.wikipedia.org/wiki/1,2-Dichloropropane

    1,2-Dichloropropane is an intermediate in the production of perchloroethylene and other chlorinated chemicals. [4] It was once used as a soil fumigant , chemical intermediate, as well as an industrial solvent and was found in paint strippers, varnishes, and furniture finish removers but some of these uses have been discontinued.

  6. Topicity - Wikipedia

    en.wikipedia.org/wiki/Topicity

    Enantiotopic groups are identical and indistinguishable except in chiral environments. For instance, the CH 2 hydrogens in ethanol (CH 3 CH 2 OH) are normally enantiotopic, but can be made different (diastereotopic) if combined with a chiral center, for instance by conversion to an ester of a chiral carboxylic acid such as lactic acid, or if coordinated to a chiral metal center, or if ...

  7. Syn and anti addition - Wikipedia

    en.wikipedia.org/wiki/Syn_and_anti_addition

    In organic chemistry, syn-and anti-addition are different ways in which substituent molecules can be added to an alkene (R 2 C=CR 2) or alkyne (RC≡CR).The concepts of syn and anti addition are used to characterize the different reactions of organic chemistry by reflecting the stereochemistry of the products in a reaction.

  8. Crystallographic point group - Wikipedia

    en.wikipedia.org/wiki/Crystallographic_point_group

    For example, the point groups 1, 2, and m contain different geometric symmetry operations, (inversion, rotation, and reflection, respectively) but all share the structure of the cyclic group C 2. All isomorphic groups are of the same order , but not all groups of the same order are isomorphic.

  9. Cyclopropane - Wikipedia

    en.wikipedia.org/wiki/Cyclopropane

    Cyclopropane was first produced via a Wurtz coupling, in which 1,3-dibromopropane was cyclised using sodium. [4] The yield of this reaction can be improved by the use of zinc as the dehalogenating agent and sodium iodide as a catalyst. [22] BrCH 2 CH 2 CH 2 Br + 2 Na → (CH 2) 3 + 2 NaBr