Search results
Results from the WOW.Com Content Network
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]
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 ...
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.
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.
The molecular formula C 3 H 6 Cl 2 (molar mass: 112.98 g/mol, exact mass: 111.9847 u) may refer to: 1,2-Dichloropropane; 1,3-Dichloropropane
The possible screw axes are: 2 1, 3 1, 3 2, 4 1, 4 2, 4 3, 6 1, 6 2, 6 3, 6 4, and 6 5. Wherever there is both a rotation or screw axis n and a mirror or glide plane m along the same crystallographic direction, they are represented as a fraction n m {\textstyle {\frac {n}{m}}} or n/m .
In cine-substitution, the entering group takes up a position adjacent to that occupied by the leaving group. For example, cine-substitution is observed in aryne chemistry. [4] Tele-substitution occurs when the new position is more than one atom away on the ring. [5]
Many of the crystallographic point groups share the same internal structure. 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.